Articular step-off and risk of post-traumatic osteoarthritis. Evidence today

Biomechanical comparisons of plate placement for medial tibial plateau fractures (Schatzker type IV): A biomechanical study using porcine tibias

INTRODUCTION

Biomechanical studies on medial tibial plateau fractures (MTPFs) (Schatzker classification type IV) are currently few, while studies using locking plates (LPs) placed on medial proximal tibias are unavailable. Hence, we compared the biomechanical properties of plate osteosynthesis at the medial and anteromedial placements using large- and small-fragment LPs in porcine bones.

MATERIALS AND METHODS

MTPFs were internally fixed using LPs on 40 porcine tibias. Specimens were equally divided into four groups: medial placement using a large-fragment LP (LPs for the medial (LM) group), anteromedial placement using a large-fragment LP (LAM group), medial placement using a small-fragment LP (SM group), and anteromedial placement using a small-fragment LP (SAM group). The translation patterns of the constructs in each group were examined by cycling loading test (displacement and translation along the mechanical axis at 10-100, 100-500, 500-1000, 1000-1500, and 1500-2000 cycles). Then, articular gaps and step-off changes after 2000 cycles were compared among the four groups.

RESULTS

One-way analysis of variance (ANOVA) revealed no significant differences in displacement and translation during cyclic loading. One-way ANOVA followed by post hoc analysis revealed that the anterior gap was lower in LPs for the medial (LM) than in SM (P = 0.029) and SAM (P = 0.0026). The central gap was also lower in LM than in SM (P = 0.042) and SAM (P < 0.001), and it was lower in LAM than in SAM (P = 0.047). Likewise, the posterior gap was lower in LM than in LAM (P = 0.025) and SAM (P < 0.001). Furthermore, the central step-off of SAM was higher than that of LM, LAM, and SM (P < 0.001, P = 0.0014, and P = 0.0077, respectively). The posterior step-off was lower in LM than in SAM and LAM (P = 0.037 and P < 0.001), and it was also lower in SM than in SAM (P = 0.0082).

CONCLUSION

Medial LP placement for MTPFs in porcine bones resulted in significantly lower posterior step-offs after cyclic loading than anteromedial placement, and large-fragment LPs for MTPFs caused significantly lower fracture gaps in the central articular after cyclic loading than small-fragment LPs.

What Is the Patient-reported Outcome and Complication Incidence After Operative Versus Nonoperative Treatment of Minimally Displaced Tibial Plateau Fractures?

BACKGROUND

Much controversy remains about whether minimally displaced tibial plateau fractures should be treated operatively or nonoperatively. It is generally accepted that gaps and stepoffs up to 2 mm can be tolerated, but this assumption is based on older studies using plain radiographs instead of CT to assess the degree of initial fracture displacement. Knowledge regarding the relationship between the degree of fracture displacement and expected functional outcome is crucial for patient counseling and shared decision-making, specifically in terms of whether to perform surgery.

QUESTIONS/PURPOSES

(1) Is operative treatment associated with improved patient-reported outcomes compared with nonoperative treatment in minimally displaced tibial plateau fractures (fractures with up to 4 mm of displacement)? (2) What is the difference in the risk of complications after operative versus nonoperative treatment in minimally displaced tibial plateau fractures?

METHODS

A multicenter, cross-sectional study was performed in patients treated for tibial plateau fractures between 2003 and 2019 at six hospitals. Between January 2003 and December 2019, a total of 2241 patients were treated for tibial plateau fractures at six different trauma centers. During that time, the general indication for open reduction and internal fixation (ORIF) was intra-articular displacement of > 2 mm. Patients treated with ORIF and those treated nonoperatively were potentially eligible; 0.2% (4) were excluded because they were treated with amputation because of severe soft tissue damage, whereas 4% (89) were excluded because of coexisting conditions that complicated outcome measurement including Parkinson disease, cerebrovascular accident, or paralysis (conditions causing an inability to walk). A further 2.7% (60) were excluded because their address was unknown, and 1.4% (31) were excluded because they spoke a language other than Dutch. Based on that, 1328 patients were potentially eligible for analysis in the operative group and 729 were potentially eligible in the nonoperative group. At least 1 year after injury, all patients were approached and asked to complete the Knee injury and Osteoarthritis Outcome Scale (KOOS) questionnaire. A total of 813 operatively treated patients (response percentage: 61%) and 345 nonoperatively treated patients (response percentage: 47%) responded to the questionnaire. Patient characteristics including age, gender, BMI, smoking, and diabetes were retrieved from electronic patient records, and imaging data were shared with the initiating center. Displacement (gap and stepoff) was measured for all participating patients, and all patients with minimally displaced fractures (gap or stepoff ≤ 4 mm) were included, leaving 195 and 300 in the operative and nonoperative groups, respectively, for analysis here. Multivariate linear regression was performed to assess the association of treatment choice (nonoperative or operative) with patient-reported outcomes in minimally displaced fractures. In the multivariate analysis, we accounted for nine potential confounders (age, gender, BMI, smoking, diabetes, gap, stepoff, AO/OTA classification, and number of involved segments). In addition, differences in complications after operative and nonoperative treatment were assessed. The minimum clinically important differences for the five subscales of the KOOS are 11 for symptoms, 17 for pain, 18 for activities of daily living, 13 for sports, and 16 for quality of life.

RESULTS

After controlling for potentially confounding variables such as age, gender, BMI, and AO/OTA classification, we found that operative treatment was not associated with an improvement in patient-reported outcomes. Operative treatment resulted in poorer KOOS in terms of pain (-4.7 points; p = 0.03), sports (-7.6 points; p = 0.04), and quality of life (-7.8 points; p = 0.01) compared with nonoperative treatment, but those differences were small enough that they were likely not clinically important. Patients treated operatively had more complications (4% [7 of 195] versus 0% [0 of 300]; p = 0.01) and reoperations (39% [76 of 195] versus 6% [18 of 300]; p < 0.001) than patients treated nonoperatively. After operative treatment, most reoperations (36% [70 of 195]) consisted of elective removal of osteosynthesis material.

CONCLUSION

No differences in patient-reported outcomes were observed at midterm follow-up between patients treated surgically and those treated nonsurgically for tibial plateau fractures with displacement up to 4 mm. Therefore, nonoperative treatment should be the preferred treatment option in minimally displaced fractures. Patients who opt for nonoperative treatment should be told that complications are rare, and only 6% of patients might undergo surgery by midterm follow-up. Patients who opt for surgery of a minimally displaced tibial plateau fracture should be told that complications may occur in up to 4% of patients, and 39% of patients may undergo a secondary intervention (most of which are elective implant removal).

LEVEL OF EVIDENCE

Level III, therapeutic study.

Exposure of Hoffa Fractures Is Improved by Posterolateral and Posteromedial Extensile Approaches: A Qualitative and Quantitative Anatomical Study

BACKGROUND

The current literature lacks recommendations regarding surgical approaches to best visualize and reduce Hoffa fractures. The aims of this study were to (1) define surgical corridors to the posterior portions of the lateral and medial femoral condyles and (2) compare the articular surface areas visible with different approaches.

METHODS

Eight fresh-frozen human cadaveric knees (6 male and 2 female donors; mean age, 68.2 ± 10.2 years) underwent dissection simulating 6 surgical approaches to the distal femur. The visible articular surface areas for each approach were marked using an electrocautery device and subsequently analyzed using image-processing software. The labeled areas of each femoral condyle were statistically compared.

RESULTS

At 30° of flexion, visualization of the posterior portions of the lateral and medial femoral condyles was not possible by lateral and medial parapatellar approaches, as only the anterior 29.4% ± 2.1% of the lateral femoral condyle and 25.6% ± 2.8% of the medial condyle were exposed. Visualization of the lateral femoral condyle was limited by the posterolateral ligamentous structures, hence a posterolateral approach only exposed its central (13.1% ± 1.3%) and posterior (12.4% ± 1.1%) portions. Posterolateral extension by an osteotomy of the lateral femoral epicondyle significantly improved the exposure to 53.4% ± 2.7% and, when combined with a Gerdy's tubercle osteotomy, to 70.9% ± 4.1% (p < 0.001). For the posteromedial approach, an arthrotomy between the anteromedial retinaculum and the superficial medial collateral ligament, and one between the posterior oblique ligament and the medial gastrocnemius tendon, allowed visualization of the central (13.5% ± 2.2%) and the posterior (14.6% ± 2.3%) portions of the medial femoral condyle, while a medial femoral epicondyle osteotomy significantly improved visualization to 66.1% ± 5.5% (p < 0.001).

CONCLUSIONS

Visualization of the posterior portions of the femoral condyles is limited by the specific anatomy of each surgical corridor. Extension by osteotomy of the femoral epicondyles and Gerdy's tubercle significantly improved articular surface exposure of the femoral condyles.

CLINICAL RELEVANCE

Knowledge of the surgical approach-specific visualization of the articular surface of the femoral condyles might be helpful to properly reduce small Hoffa fragments.

Establishment and preliminary evaluation of CT-based classification for distal radius fracture

Establish a new classification system of distal radius fracture based on computed tomographic (CT), and evaluate its reliability and reproducibility preliminarily, and provide a new theoretical reference for clinicians to use the clinical classification system. The imaging data and clinical data of 204 inpatients with distal radius fracture during 6 years from January 1, 2014 to January 1, 2019 in orthopaedic department were analyzed retrospectively and classified based on CT. Three observers evaluated the image data of 48 randomly selected cases based on CT at different time nodes of T1 and T2. Cohen's kappa was used to calculate the consistency. At the last follow-up, patients' Disabilities of the Arm, Shoulder and Hand (DASH), Patient Rated Wrist Evaluation (PRWE), and VAS scores were collected. Among 204 cases, there were 12 cases of type 1, including 6 cases of type 1-D, 4 cases of type 1-V and 2 cases of type 1-R. There were 6 cases of type 2, including 2 cases of type 2-DV, 2 cases of type 2-DR and 2 cases of type 2-VR. There were 186 cases of type 3, including 32 cases of type 3-0, 127 cases of type 3-1 and 27 cases of type 3-2. There was no significant difference in DASH, PRWE and VAS scores among all types (P > 0.05). The results of interobserver reproducibility were kappa = 0.985, ICC = 0.984 in the first evaluation, kappa = 0.986, ICC = 0.986 in the second evaluation. The results of intraobserver reproducibility were O1 = 0.991, O2 = 0.991, O3 = 0.989 respectively. The new classification system of distal radius fracture based on CT has theoretical and practical significance for incision selection, fracture reduction and internal fixation. 123 classification system is clear, comprehensive, easy to understand and remember. Moreover, it has higher interobserver reliability and intraobserver reproducibility than other systems reported at present.

Prospective evaluation of the surgical stabilization and outcome of canine tibial plateau fractures in three cases

OBJECTIVE

To report the surgical approaches and stabilization of lateral and medial tibial plateau fractures (TPF), as well as the long-term outcome following repair.

STUDY DESIGN

Prospective series of three client-owned dogs.

ANIMALS

Three dogs.

METHODS

For the two lateral TPF cases (Unger type 41-B1), the surgical approach included separation of the lateral collateral ligament and long digital extensor tendon. The lateral meniscus was elevated to allow visualization of the tibial surface and assess fracture reduction. The first case was repaired using two 2.0 mm lag screws (with washers). The second case sustained a lateral TPF, fibular fracture and concurrent tubercle of Gerdy fracture. Both tibial fractures were stabilized using two 2.0 mm lag screws with washers and two 0.9 mm Kirschner wires (K-wires). A third case, diagnosed with an Unger type 41-B2 medial TPF, was treated using 0.9 mm K-wires and 22-gauge tension band.

RESULTS

There were no major complications noted. One minor complication occurred (screw yield two weeks postoperatively). By 8 weeks, all patients reached clinical union with good limb function. Owners were contacted 9-36 months postoperatively. LOAD scores and examinations were performed for two of three patients; the third patient was not contactable after relocating out of state. Both cases with completed questionnaires had a LOAD score of 5/52.

CONCLUSION

Tibial plateau fractures are rare in canine patients. While challenging, they can be successfully managed using a combination of lag screws, K-wires, and tension band.

CLINICAL SIGNIFICANCE

Surgical stabilization of TPF is feasible and may reduce the risk of meniscal injury.

Atypical anterior wall fracture extending to anterior inferior iliac spine with preservation of pelvic brim: A case report and literature review

Key Clinical Message

Anterior acetabular wall fractures that extend into the anterior inferior iliac spine are more likely to be unstable, and more likely to require surgical fixation.

Abstract

Conventional acetabular anterior wall fractures originate below the anterior inferior iliac spine (AIIS) level and involve the pelvic brim. Since surgical treatment is preserved for instability and hip incongruency, atypical variation of this fracture usually jeopardizes hip stability. We report on a 33-year-old case of an acetabular anterior wall fracture extending to the anterior inferior iliac spine. He was prepared for the stress test and hip stability checked, that was unstable in extension and external rotation. The joint was exposed with the Smith-Peterson approach. Hip congruency was restored, and the AIIS fragment was stabilized by open reduction. Acetabular anterior wall fracture involving AIIS with preservation of pelvic brim is a rare equivalent of anterior wall fracture that jeopardizes hip stability and should be managed surgically. Anterior approaches are preferred in order to visualize the joint.

A Comprehensive Review on Managing Fracture Calcaneum by Surgical and Non-surgical Modalities

This comprehensive review delves into the multifaceted landscape of calcaneal fractures, thoroughly examining their aetiology, clinical presentation, and diverse management strategies. Encompassing surgical and non-surgical approaches, the review scrutinises critical aspects such as patient compliance, rehabilitation protocols, and long-term follow-up considerations. Surgical modalities, propelled by recent innovations like minimally invasive techniques and advanced fixation materials, are juxtaposed with non-surgical interventions, emphasising the pivotal role of patient education and adherence to optimise outcomes. The synthesis of critical findings underscores the need for individualised care and multidisciplinary collaboration in clinical practice. Moreover, the review outlines recommendations for healthcare practitioners and identifies promising areas for future research, including biomechanical studies and telerehabilitation. This comprehensive exploration aims to contribute to the ongoing evolution of calcaneal fracture management, ultimately enhancing patient care and outcomes in this complex orthopaedic realm.

Limb position affects intraoperative assessment of condylar width

PURPOSE

We sought to define how changes in position and rotation of fluoroscopic imaging may affect the assessment of condylar widening intraoperatively.

METHODS

Thirty-three patients with tibial plateau fractures were prospectively identified and included in this study. Fluoroscopic images of the uninjured tibial plateau were obtained in (1) full extension and (2) slight flexion on foam ramp. Beginning with a plateau view, additional views of the tibial plateau were then obtained by rotating the fluoroscope around the knee in 5 degree increments up to 15 degrees in both internal and external rotation. Measurements of distal femoral condylar width (DFW), distal femoral articular width (FAW), proximal tibial articular width (TAW) and lateral plateau width (LPW) were performed.

RESULTS

LPW was decreased in flexion compared to extension at all degrees of rotation (p = 0.04-0.00001). There was a trend toward increasing LPW with increasing degrees of internal rotation which reached significance at 15˚ of internal rotation when the knee was flexed. On ANOVA, there was a significant difference of LPW with increasing degree of internal rotation when the knee was in flexion (p = 0.008), but not in extension. There were no differences in DFW, FAW, TAW and DFW/TAW at any point though LPW was decreased in flexion at all degrees of rotation. The FAW/TAW ratio was increased in flexion at all degrees of rotation.

DISCUSSION

The knee in flexion will underestimate the measurement of condylar width compared to the knee in full extension, by ~ 2 mm. Rotation of the knee, in comparison, did not have a significant effect on condylar width assessment.

LEVEL OF EVIDENCE

Diagnostic II.

Modern osteosynthesis of periarticular fractures: The role of provisional fixation revisited

Periarticular fractures are complex injuries affecting the joint articular surface, the subchondral area, the metaphyseal region, the surrounding soft tissue envelope and not infrequently the ligamentous structures. The management of these injuries has evolved over the years, from one stage to two stage procedures thus facilitating soft tissue resuscitation, adequate pre-operative planning and the use of biologics optimizing the conditions for definitive fixation for a successful long-term outcome. Provisional fixation constitutes an essential step in the surgical treatment of these fractures. Herein, the role of provisional fixation as well as strategies on how they should be applied are discussed. The aim is to revisit this important step of provisional fracture fixation since its introduction by Albin Lambotte, in the early 1900's.

Functional assessment and outcome following surgical treatment of displaced tibial plateau fractures: a retrospective analysis

PURPOSE

Patients with tibial plateau fractures (TPF) are at risk of long-term hampered bipedal locomotion. A retrospective single-center study using patient-related outcome measures and a sophisticated assessment of walking abilities was conducted.

METHODS

Adults receiving surgical treatment of an isolated TPF between January 2012 and December 2016 received the KOOS questionnaire together with the invitation for an extensive follow-up examination on the clinical outcome including standardized assessment of the walking abilities (loadsol® system). Outcome was assessed relative to the severity of the injury or time to follow-up. Fractures were classified according to AO/OTA and Luo, respectively.

RESULTS

58 out of 132 eligible patients filled in the questionnaire and participated at a median follow-up of 3.05 years after injury. For the categories "pain", "mobility", and "daily life activities", all patients were rather satisfied and this was virtually not related to the time between fracture and assessment. Relevant limitations were reported for "sports and recreational activities" and "quality of life". Loading of the previously fractured leg was most evidently changed on stairs and outdoor walking. Outcome was not related to either fracture type severity or time from injury.

CONCLUSION

Outcome after an isolated TPF is neither related to fracture type, severity of the fracture nor time from injury. Simple gait analysis techniques relying on different tasks appear to yield a more sophisticated image on functional deficits after TPF than classical exam of ground-level walking and correlate quite well with validated patient-related outcome measures as the KOOS.

Efficacy of Cal-Cemex as bone substitute for tibial plateau fractures

BACKGROUND

Various factors influence treatment and outcomes in tibial plateau fractures. Bone defects are among them. Many materials have been proposed to address this problem: allograft, bone-cements and various bone substitutes (BSM). Cal-Cemex (β-tricalciophosphate and polymethylmethacrylate) is a new hybrid bi-component BSM. A retrospective multicenter study was conducted based on the clinical experience of three European Hospitals, to demonstrate its clinical effectiveness, versatility and safety.

MATERIALS AND METHODS

From December 2016 to March 2022, 45 displaced tibial plateau fractures were treated with internal fixation and augmentation using Cal-Cemex. The average age was 55.9 years. According to Schatzker classification, we included 13 type II, 24 type III, 3 type V and 4 type VI fractures. The postoperative follow-up (FU) consisted of clinical and radiological examinations at 6 and 12 weeks and 1 year after surgery. A CT scan was performed preoperatively and 1 year after surgery. Full weight bearing was permitted after less than 6 weeks. Clinical data were collected from patient charts, while functional data were evaluated using the Rasmussen knee function score, the KOOS score and the Hospital for Special Surgery knee rating score (HSS), to evaluate the range of motion, axis and functionality of the knee.

RESULTS

The average FU was 42.8 months. CT scans taken at 1 year demonstrated a good surface osteointegration without radiolucent lines or osteolysis with good evidence of interdigitation and even bone ingrowth. At 1-year FU, the mean Rasmussen score was 24.7, the mean KOOS score was 90.7 and the mean HSS was 89.9 and the average full weight-bearing period 34.9. No patients had hardware failure or fracture secondary displacement.

DISCUSSION

Cal-Cemex combines biological features and good mechanical performances. It guarantees biocompatibility and osteoconductivity, although it is not fully reabsorbable; β-tricalciophosphate component gives macro- and microporosity that allow fluids to penetrate inside the material, to stimulate bone ingrowth.

CONCLUSIONS

The study suggests that Cal-Cemex is an option for tibial plateau fractures, where augmentation and support are necessary for early full weight bearing. The absence of major complications, ease of application, the possibility to cut and perforate this material support its extensive use in bone augmentation for trauma cases.

Adjunctive intraosseous wiring fixation technique for the comminuted distal humeral fractures

Distal humeral fractures are among the most challenging injuries to treat. Although precise repair of the articular surface is essential during surgery, accurate reconstruction of the metaphysis contributes to the overall stability of the fracture construct. The intraosseous wiring technique has been used for small-fragment fractures. However, its efficacy as an adjunct for distal humerus fixation has yet to be thoroughly investigated. This study aimed to demonstrate the applicability of this technique to comminuted, distal humeral fractures. In this retrospective case series, we describe 6 cases of intra-articular distal humerus fractures treated with this technique, followed by dual plating. We observed successful bone union in all patients, with the Mayo Elbow Performance Scores indicating "good" to "excellent" clinical outcomes for this procedure at the final follow-up. We believe that this intraosseous wiring technique should be an integral part of the toolbox of every surgeon because it is a relatively simple and highly effective procedure that requires no special instrument and can be used on various types of fractures.

Radiographic Evidence of Early Posttraumatic Osteoarthritis following Tibial Plateau Fracture Is Associated with Poorer Function

To determine if radiographic evidence of posttraumatic osteoarthritis (PTOA) following tibial plateau fracture correlates with poorer clinical and functional outcomes, patients with tibial plateau fractures were followed at 3, 6, and 12 months. All patients had baseline radiographs and computed tomography scan. Radiographs obtained at each follow-up were reviewed for healing, articular incongruence, hardware positional changes, and the development of postinjury arthritic change. Cohorts were determined based on the presence (PTOA) or absence (NPTOA) of radiographic evidence of PTOA. Demographics, fracture classification, complications, additional procedures, and functional status were compared between cohorts. Sixty patients had radiographic evidence of PTOA on follow-up radiographs at a mean final follow-up of 24.2 months. The NPTOA cohort was composed of 210 patients who were matched to the PTOA cohort based on age and Charlson comorbidity index. Mean time to fracture union for the overall cohort was 4.86 months. Cohorts did not differ in Schatzker classification, time to healing, injury mechanism, or baseline Short Musculoskeletal Function Assessment (SMFA). Patients with PTOA had a greater degree of initial depression and postoperative step-off, higher incidence of initial external fixator usage, higher rates of reoperation for any reason, and higher rates of wound complications. Associated soft tissue injury and meniscal repair did not coincide with the development of PTOA. Range of motion and SMFA scores were significantly worse at all time points in patients with PTOA. Although fracture patterns are similar, patients who required an initial external fixator, had a greater degree of initial depression or residual articular incongruity, underwent more procedures, and developed an infection were found to have increased incidence of PTOA. Radiographic evidence of osteoarthritis correlated with worse functional status in patients. The goal of surgery should be restoration of articular congruity and stability to mitigate the risk of PTOA, although this alone may not prevent degenerative changes. Patients with early loss of range of motion should be aggressively treated as this may precede the development of PTOA.

Initial and Residual 3D Fracture Displacement Is Predictive for Patient-Reported Functional Outcome at Mid-Term Follow-Up in Surgically Treated Tibial Plateau Fractures

BACKGROUND

Conventional measures of fracture displacement have low interobserver reliability. This study introduced a novel 3D method to measure tibial plateau fracture displacement and its impact on functional outcome.

METHODS

A multicentre study was conducted on patients who had tibial plateau fracture surgery between 2003 and 2018. Eligible patients had a preoperative CT scan (slice thickness ≤ 1 mm) and received a Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire. A total of 362 patients responded (57%), and assessment of initial and residual fracture displacement was performed via measurement using the 3D gap area (mm2). Patients were divided into four groups based on the 3D gap area size. Differences in functional outcome between these groups were assessed using analysis of variance (ANOVA). Multiple linear regression was used to determine the association between fracture displacement and patient-reported outcome.

RESULTS

Functional outcome appeared significantly worse when initial or residual fracture displacement increased. Multivariate linear regression showed that initial 3D gap area (per 100 mm2) was significantly negatively associated with all KOOS subscales: symptoms (-0.9, p < 0.001), pain (-0.0, p < 0.001), ADL (-0.8, p = 0.002), sport (-1.4, p < 0.001), and QoL (-1.1, p < 0.001). In addition, residual gap area was significantly negatively associated with the subscales symptoms (-2.2, p = 0.011), ADL (-2.2, p = 0.014), sport (-2.6, p = 0.033), and QoL (-2.4, p = 0.023).

CONCLUSION

A novel 3D measurement method was applied to quantify initial and residual displacement. This is the first study which can reliably classify the degree of displacement and indicates that increasing displacement results in poorer patient-reported functional outcomes.

Exposure of Tissue-Engineered Cartilage Analogs to Synovial Fluid Hematoma After Ankle Fracture Is Associated With Chondrocyte Death and Altered Cartilage Maintenance Gene Expression

BACKGROUND

The first stage of fracture healing consists of hematoma formation with recruitment of proinflammatory cytokines and matrix metalloproteinases. Unfortunately, when there is an intra-articular fracture, these inflammatory mediators are not retained at the fracture site, but instead, envelop the healthy cartilage of the entire joint via the synovial fluid fracture hematoma (SFFH). These inflammatory cytokines and matrix metalloproteinases are known factors in the progression of osteoarthritis and rheumatoid arthritis. Despite the known inflammatory contents of the SFFH, little research has been done on the effects of the SFFH on healthy cartilage with regard to cell death and alteration in gene expression that could lead to posttraumatic osteoarthritis (PTOA).

METHODS

SFFH was collected from 12 patients with intraarticular ankle fracture at the time of surgery. Separately, C20A4 immortalized human chondrocytes were 3-dimensionally cultured to create scaffold-free cartilage tissue analogs (CTAs) to simulate healthy cartilage. Experimental CTAs (n = 12) were exposed to 100% SFFH for 3 days, washed, and transferred to complete media for 3 days. Control CTAs (n = 12) were simultaneously cultured in complete medium without exposure to SFFH. Subsequently, CTAs were harvested and underwent biochemical, histological, and gene expression analysis.

RESULTS

Exposure of CTAs to ankle SFFH for 3 days significantly decreased chondrocyte viability by 34% (P = .027). Gene expression of both COL2A1 and SOX9 were significantly decreased after exposure to SFFH (P = .012 and P = .0013 respectively), while there was no difference in COL1A1, RUNX2, and MMP13 gene expression. Quantitative analysis of Picrosirius red staining demonstrated increased collagen I deposition with poor ultrastructural organization in SFFH-exposed CTAs.

CONCLUSION

Exposure of an organoid model of healthy cartilage tissue to SFFH after intraarticular ankle fracture resulted in decreased chondrocyte viability, decreased expression of genes regulating normal chondrocyte phenotype, and altered matrix ultrastructure indicating differentiation toward an osteoarthritis phenotype.

CLINICAL RELEVANCE

The majority of ankle fracture open reduction and internal fixation does not occur immediately after fracture. In fact, typically these fractures are treated several days to weeks later in order to let the swelling subside. This means that the healthy innocent bystander cartilage not involved in the fracture is exposed to SFFH during this time. In this study, the SFFH caused decreased chondrocyte viability and specific altered gene expression that might have the potential to induce osteoarthritis. These data suggest that early intervention after intraarticular ankle fracture could possibly mitigate progression toward PTOA.

Mismatch between Clinical-Functional and Radiological Outcome in Tibial Plateau Fractures: A Retrospective Study

BACKGROUND

The evaluation of tibial plateau fractures (TPF) encompasses the assessment of clinical-functional and radiological parameters. In this study, the authors aimed to investigate the potential correlation between these parameters by utilizing both the clinical-functional and the modified radiological Rasmussen score.

METHODS

In this retrospective monocentric study conducted at a level-I trauma center, patients who underwent surgery between January 2014 and December 2019 due to a TPF were included. The clinical-functional Rasmussen score prior to the injury, at 1-year postoperatively, and during the last follow-up (minimum 18 months) was assessed using a standardized questionnaire. Additionally, the modified radiological Rasmussen score was determined at the 1-year postoperative mark using conventional radiographs in two planes.

RESULTS

A total of 50 patients were included in this study, comprising 40% (n = 20) men, and 60% (n = 30) women, with an average age of 47 ± 11.8 years (range 26-73 years old). Among them, 52% (n = 26) had simple fractures (classified according to Schatzker I-III), while 48% (n = 24; according to Schatzker IV-VI) had complex fractures. The mean follow-up was 3.9 ± 1.6 years (range 1.6-7.5 years). The functional Rasmussen score assessed before the injury and at follow-up showed an "excellent" average result. However, there was a significant difference in the values of complex fractures compared to before the injury. One year postoperatively, both the clinical-functional score and the modified radiological score demonstrated a "good" average result. The "excellent" category was more frequently observed in the functional score, while the "fair" category was more common in the radiological score. There was no agreement between the categories in both scores in 66% of the cases.

CONCLUSIONS

The data from this retrospective study demonstrated that patients with TPF are able to achieve a nearly equivalent functional level in the medium-term after a prolonged recovery period, comparable to their pre-injury state. However, it is important to note that the correlation between clinical-functional and radiological parameters is limited. Consequently, in order to create prospective outcome scores, it becomes crucial to objectively assess the multifaceted nature of TPF injuries in more detail, both clinically and radiologically.

Radiographic Predictors of Conversion to Total Knee Arthroplasty After Tibial Plateau Fracture Surgery: Results in a Large Multicenter Cohort

BACKGROUND

Radiographic measurements of initial displacement of tibial plateau fractures and of postoperative reduction are used to determine treatment strategy and prognosis. We assessed the association between radiographic measurements and the risk of conversion to total knee arthroplasty (TKA) at the time of follow-up.

METHODS

A total of 862 patients surgically treated for tibial plateau fractures between 2003 and 2018 were eligible for this multicenter cross-sectional study. Patients were approached for follow-up, and 477 (55%) responded. The initial gap and step-off were measured on the preoperative computed tomography (CT) scans of the responders. Condylar widening, residual incongruity, and coronal and sagittal alignment were measured on postoperative radiographs. Critical cutoff values for gap and step-off were determined using receiver operating characteristic curves. Postoperative reduction measurements were categorized as adequate or inadequate on the basis of cutoff values in international guidelines. Multivariable analysis was performed to assess the association between each radiographic measurement and conversion to TKA.

RESULTS

Sixty-seven (14%) of the patients had conversion to TKA after a mean follow-up of 6.5 ± 4.1 years. Assessment of the preoperative CT scans revealed that a gap of >8.5 mm (hazard ratio [HR] = 2.6, p < 0.001) and step-off of >6.0 mm (HR = 3.0, p < 0.001) were independently associated with conversion to TKA. Assessment of the postoperative radiographs demonstrated that residual incongruity of 2 to 4 mm was not associated with increased risk of TKA compared with adequate fracture reduction of <2 mm (HR = 0.6, p = 0.176). Articular incongruity of >4 mm resulted in increased risk of TKA. Coronal (HR = 1.6, p = 0.05) and sagittal malalignment (HR = 3.7 p < 0.001) of the tibia were strongly associated with conversion to TKA.

CONCLUSIONS

Substantial preoperative fracture displacement was a strong predictor of conversion to TKA. Postoperative gaps or step-offs of >4 mm as well as inadequate alignment of the tibia were strongly associated with an increased risk of TKA.

LEVEL OF EVIDENCE

Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Combined approach versus single Henry approach for fixation of die-punch distal radius fractures: a retrospective study

BACKGROUND

Distal radius fracture (DRF) is one of the most common orthopaedic-related traumas. DRF patients with die-punch fractures have a higher risk of loss of reduction, poorer functional outcomes, and increased risk of complications even after open reduction and internal fixation (ORIF). According to the three-column theory, the lunate fossa is an important part of the intermediate column for load bearing. When the distal radius fracture involves the lunate fossa, adequate anatomical reduction can have an important impact on the prognosis of wrist function. Herein, we used the combined volar and dorsal approach, and the dorsal approach was used to assist in bone grafting or dorsal plate fixation in reducing fractures. We compare the combined approach versus the Henry approach for the fixation of die-punch distal radius fractures.

METHODS

We reviewed patients who were admitted for surgery for die-punch fractures from January 2016 to June 2021. The patients were followed-up after surgery to measure and evaluate their Gartland-Werley wrist score, wrist range of motion (ROM), and follow-up imaging data.

RESULTS

There were 21 patients in the volar locking plate (VLP) group and 10 patients in the combined approach group. The majority of fractures in the VLP and combined approach groups were AO B and C fractures, respectively. The cause of injury and AO fracture classification showed significant differences between the two groups, and there was no difference in age or sex between the two groups. There was no significant difference in ROM between the two groups, but the VLP group presented a better Gartland-Werley score and volar tilt angle, and the combined group presented better maintenance in radial height and articular congruity.

CONCLUSIONS

Reduction through the combined palmar and dorsal approach supplemented by bone grafting or dorsal plate fixation is an effective method for the treatment of die-punch distal radius fractures, which provides a new option for the treatment of die-punch fractures.

Reconstruction of a neglected hyperextension-bicondylar tibial plateau fracture 9 months after original injury and review of the literature. What outcomes can be expected?

Tibial plateau fractures range from simple to complex. Most complex injury types are managed surgically but for some, a decision is made to treat without surgery. We present a case that was managed non-operatively but due to failure of bone union, later required surgical intervention. We discuss the choice of management and potential risk factors influencing outcome.

How controlled motion alters the biophysical properties of musculoskeletal tissue architecture

INTRODUCTION

Movement is fundamental to the normal behaviour of the hand, not only for day-to-day activity, but also for fundamental processes like development, tissue homeostasis and repair. Controlled motion is a concept that hand therapists apply to their patients daily for functional gains, yet the scientific understanding of how this works is poorly understood.

PURPOSE OF THE ARTICLE

To review the biology of the tissues in the hand that respond to movement and provide a basic science understanding of how it can be manipulated to facilitate better functionThe review outlines the concept of controlled motion and actions across the scales of tissue architecture, highlighting the the role of movement forces in tissue development, homeostasis and repair. The biophysical behaviour of mechanosensitve tissues of the hand such as skin, tendon, bone and cartilage are discussed.

CONCLUSION

Controlled motion during early healing is a form of controlled stress and can be harnessed to generate appropriate reparative tissues. Understanding the temporal and spatial biology of tissue repair allows therapists to tailor therapies that allow optimal recovery based around progressive biophysical stimuli by movement.

Risk factors for intra-articular involvement in proximal humeral fractures

INTRODUCTION

Identification of intra-articular involvement in proximal humeral fractures is important for operative decision making. The aim of this study was to identify the risk factors associated with intra-articular involvement in proximal humeral fractures.

MATERIALS AND METHODS

One hundred consecutive three-dimensional computed tomography reconstructions of proximal humeral fractures were identified. The fracture lines were then accurately transcribed onto a two-dimensional superior view of the humeral head and each fracture was assessed for intra-articular involvement. Statistical analyses were undertaken to identify risk factors for intra-articular involvement and extent of involvement. Furthermore, for each risk factor, common fracture patterns were identified and compared to anatomical landmarks.

RESULTS

Overall, 58% of the fractures involved the articular surface. High-energy mechanism, female gender, age ≥ 65, and posterior dislocation were risk factors for intra-articular involvement. Low-energy mechanism, female gender, age ≥ 65, varus angulation, and posterior dislocation were risk factors for increased extension of the fracture onto the articular surface.

CONCLUSION

Intra-articular involvement in proximal humeral fractures is influenced by demographics and fracture characteristics (mechanism of injury, angulation, and dislocation). Patients with identified risk factors should be appropriately evaluated for intra-articular fractures during preoperative planning to assist in operative decision making.

LEVEL OF EVIDENCE

Basic science; anatomy study.

Influence of articular step-off on contact mechanics in fractures of the posterolateral-central tibial plateau - a biomechanical study

BACKGROUND

The posterior quadrants of the tibial plateau are frequently involved in OTA type C tibial plateau fractures. The biomechanical influence of a residual articular step-off of the posterolateral-central (PLC) segment, which is difficult to visualize intraoperatively, remains unclear. Therefore, aim of this study was to investigate the contact area and stress of the tibial plateau in cases of different articular step-offs of the PLC segment.

METHODS

Seven human cadaveric knees were used to simulate articular impressions of the PLC segment with step-offs of 1 mm, 3 mm, and 5 mm. The knees were axially loaded up to 150 N during a total of 25 dynamic cycles of knee flexion up to 90°. Pressure mapping sensors were inserted into the medial and lateral joint compartments beneath the menisci to measure articular contact area and stress.

RESULTS

Between 60° and 90° of knee flexion, increasing PLC segment impressions of the tibial plateau led to increasing contact stress and a significantly reduced contact area. The largest decrease in the contact area was 30 %, with an articular step-off of 5 mm (0.003). An increase in contact stress, especially from a 3-mm step-off, was measured, with a doubling of the mean contact stress at 3-mm and 5-mm step-offs and 90° knee flexion (p = 0.06/0.05).

CONCLUSION

From a biomechanical point of view, posterior impressions of the PLC segment greater than a 1-mm step-off should be addressed as anatomically as possible, especially in active patients with the need for higher knee flexion angles.

Intra-articular fragment mapping in associated both-column acetabular fractures

INTRODUCTION

Associated both-column acetabular fractures (ABC-AF) are complex. A detailed description of the morphology of the articular surface of the acetabulum is not reported. This study was designed to describe the morphology of the intra-articular fragments using a fracture mapping technique to provide reference in more appropriate approach selection in surgical treatment of the fractures.

MATERIALS AND METHODS

Three-dimensional reconstruction CT images from 100 cases of ABC-AFs were retrospectively analyzed using Mimics and 3-matic software. The fractured as well as the reduced three-dimensional models were investigated, and the intra-articular fragments were identified. The distribution of the fracture lines of each main fragment and the overlapping lines of all the fragments were verified on the images.

RESULTS

The articular surface of ABC-AFS consist of three types of fragments: column fragment (CF), wall fragment (WF) and isolated fragment (IF), with the total number varying from 2 to 6. CF characterized by long fracture lines exited to periphery of innominate bone while the lines of WF were confined to the walls. IF was a free fragment found in the dome and in the quadrilateral plate. The surface was composed only by CFs in 17 cases (17%), by CFs and WFs in 59 cases (59%) and by all fragments in 24 cases (24%). The distribution of the overall fracture lines was a "dumbbell shaped" pattern, starting from the infero-anterior aspect, passing through the junction of the fossa to the anterior lunate surface and extending into the posterior region of the acetabulum.

CONCLUSIONS

The articular fragments of ABC-AFs were composed of CFs, WFs and IFs. The junction of the fossa to the anterior lunate surface and the posterior region of the rim were mostly involved. The location of the articular fragments and their connections to the periphery of the innominate may be considered in selection of approaches.

COMBINED PLATE VERSUS EXTERNAL FIXATION FOR DISTAL RADIUS FRACTURES

Objectives

This study aimed to compare the functional and radiological results of patients who had intra-articular comminuted distal radius fractures and were operated on with external fixation percutaneous pinning or the volar-dorsal combined plate osteosynthesis.

Methods

In this study, 49 patients operated on and followed up for the comminuted distal radius fractures between May 2015 and January 2019 were retrospectively evaluated. The surgical outcomes of the patients, who were operated on with combined dorsal-volar plate osteosynthesis or external fixation percutaneous pinning, were compared in this study. Functional and radiological scores were evaluated and analyzed statistically.

Results

There was no statistical difference between external fixation and volar-dorsal combined plate groups regarding the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire, the Visual Analog Scale (VAS), the Mayo scoring system, range of motion, and grip strength values.

Discussion

Although the combined volar-dorsal plate osteosynthesis technique had a longer operation time and a more complicated surgical procedure, the combined volar-dorsal plate osteosynthesis had lower complication rates and permitted early mobilization. The combined volar-dorsal plate osteosynthesis could be an alternative to external fixation percutaneous pinning. Level of Evidence III, Therapeutic Studies Investigating the Results of Treatment.

Current concepts review. Management of proximal tibial fractures

The management of proximal tibial fractures has evolved significantly in recent years. While the main goals of treatment - stability, restoration of the mechanical axis, and smooth articular surfaces - remain the same, methods have advanced substantially. In diagnostics, technical progress in CT and MR imaging has led to a better three-dimensional understanding of the injury. Newly developed classification systems such as the three-column concept of Luo et al. and the 10-segment concept of Krause et al. take this into account. Accordingly, there is a trend towards tailored approaches for particular fracture localizations. Parallel to this development, there is increasing evidence of the advantages of arthroscopically assisted surgical procedures. This Current Concepts article reviews classifications, diagnostics, treatment options as well as complications in fractures of the proximal tibia.

Functional Outcome After Nonoperative Management of Tibial Plateau Fractures in Skeletally Mature Patients: What Sizes of Gaps and Stepoffs Can be Accepted?

BACKGROUND

Gap and stepoff measurements provide information about fracture displacement and are used for clinical decision-making when choosing either operative or nonoperative management of tibial plateau fractures. However, there is no consensus about the maximum size of gaps and stepoffs on CT images and their relation to functional outcome in skeletally mature patients with tibial plateau fractures who were treated without surgery. Because this is important for patient counseling regarding treatment and prognosis, it is critical to identify the limits of gaps and stepoffs that are well tolerated.

QUESTIONS/PURPOSES

(1) In patients treated nonoperatively for tibial plateau fractures, what is the association between initial fracture displacement, as measured by gaps and stepoffs at the articular surface on a CT image, and functional outcome? (2) What is the survivorship of the native joint, free from conversion to a total knee prosthesis, among patients with tibial plateau fractures who were treated without surgery?

METHODS

A multicenter cross-sectional study was performed in all patients who were treated nonoperatively for a tibial plateau fracture between 2003 and 2018 in four trauma centers. All patients had a diagnostic CT scan, and a gap and/or stepoff more than 2 mm was an indication for recommending surgery. Some patients with gaps and/or stepoffs exceeding 2 mm might not have had surgery based on shared decision-making. Between 2003 and 2018, 530 patients were treated nonoperatively for tibial plateau fractures, of which 45 had died at follow-up, 30 were younger than 18 years at the time of injury, and 10 had isolated tibial eminence avulsions, leaving 445 patients for follow-up analysis. All patients were asked to complete the validated Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire consisting of five subscales: symptoms, pain, activities of daily living (ADL), function in sports and recreation, and knee-related quality of life (QOL). The score for each subscale ranged from 0 to 100, with higher scores indicating better function. A total of 46% (203 of 445) of patients participated at a mean follow-up of 6 ± 3 years since injury. All knee radiographs and CT images were reassessed, fractures were classified, and gap and stepoff measurements were taken. Nonresponders did not differ much from responders in terms of age (53 ± 16 years versus 54 ± 20 years; p = 0.89), gender (70% [142 of 203] women versus 59% [142 of 242] women; p = 0.01), fracture classifications (Schatzker types and three-column concept), gaps (2.1 ± 1.3 mm versus 1.7 ± 1.6 mm; p = 0.02), and stepoffs (2.1 ± 2.2 mm versus 1.9 ± 1.7 mm; p = 0.13). In our study population, the mean gap was 2.1 ± 1.3 mm and stepoff was 2.1 ± 2.2 mm. The participating patients divided into groups with increasing fracture displacement based on gap and/or stepoff (< 2 mm, 2 to 4 mm, or > 4 mm), as measured on CT images. ANOVA was used to assess whether an increase in the initial fracture displacement was associated with poorer functional outcome. We estimated the survivorship of the knee free from conversion to total knee prosthesis at a mean follow-up of 5 years using a Kaplan-Meier survivorship estimator.

RESULTS

KOOS scores in patients with a less than 2 mm, 2 to 4 mm, or greater than 4 mm gap did not differ (symptoms: 83 versus 83 versus 82; p = 0.98, pain: 85 versus 83 versus 86; p = 0.69, ADL: 87 versus 84 versus 89; p = 0.44, sport: 65 versus 64 versus 66; p = 0.95, QOL: 70 versus 71 versus 74; p = 0.85). The KOOS scores in patients with a less than 2 mm, 2 to 4 mm, or greater than 4 mm stepoff did not differ (symptoms: 84 versus 83 versus 77; p = 0.32, pain: 85 versus 85 versus 81; p = 0.66, ADL: 86 versus 87 versus 82; p = 0.54, sport: 65 versus 68 versus 56; p = 0.43, QOL: 71 versus 73 versus 61; p = 0.19). Survivorship of the knee free from conversion to total knee prosthesis at mean follow-up of 5 years was 97% (95% CI 94% to 99%).

CONCLUSION

Patients with minimally displaced tibial plateau fractures who opt for nonoperative fracture treatment should be told that fracture gaps or stepoffs up to 4 mm, as measured on CT images, could result in good functional outcome. Therefore, the arbitrary 2-mm limit of gaps and stepoffs for tibial plateau fractures could be revisited. The survivorship of the native knee free from conversion to a total knee prosthesis was high. Large prospective cohort studies with high response rates are needed to learn more about the relationship between the degree of fracture displacement and functional recovery after tibial plateau fractures.

LEVEL OF EVIDENCE

Level III, prognostic study.

Posttraumatic Arthritis After Combined Plating of Distal Radius Fractures AO Type C: A 7-Year Follow-up of 97 Cases

BACKGROUND

Volar locking plate fixation is the most common method of operative fixation of distal radius fractures (DRFs). For more complex cases, combined plating is an option for stabilizing intra-articular fragments. The prevalence of posttraumatic arthritis (PA) after an intra-articular DRF, and its relation to patient-reported outcome measures (PROMs), remains unclear. The purpose of this study was to study the prevalence of PA and its correlation to clinical outcome measures.

METHODS

We evaluated 97 consecutive patients with intra-articular DRF, operated with combined plating, 7 years postoperatively. The primary outcome measure was the prevalence of radiographic PA. Secondary outcome measures included visual analog scale (VAS) pain score, hand grip strength, wrist range of motion (ROM), Patient-Rated Wrist Evaluation (PRWE) score, and Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score. Radiographic examination was performed between 1 and 7 years postoperatively.

RESULTS

The prevalence of PA was 29% at the 7-year follow-up. No correlation was found between PA and ROM, hand grip strength, PRWE, QuickDASH, VAS pain scores, or radiographic reduction. Median wrist ROM and grip strength were significantly inferior compared with the uninjured side. Hardware removal was performed in 51.5% of cases. There were 2 cases of tendon ruptures.

CONCLUSIONS

Combined plating can yield a good clinical outcome 7 years postoperatively and a low prevalence of PA. The presence of PA did not correlate to clinical outcome measures or to the accuracy of anatomical reduction 1 year postoperatively. The frequency of tendon ruptures was acceptable, but the high frequency of hardware removal is a concern.

A review of Risk Factors for Post-traumatic hip and knee osteoarthritis following musculoskeletal injuries other than anterior cruciate ligament rupture

Post-traumatic osteoarthritis (PTOA) is a common form of osteoarthritis that might occur after any joint trauma. Most PTOA publications mainly focus on anterior cruciate ligament (ACL) injuries. However, many other traumatic injuries are associated with PTOA, not only for the knee but also for the hip joint. We aim to identify and summarize the existing literature on the musculoskeletal injuries associated with knee and hip PTOA and their risk factors in determining those with a worse prognosis, excluding ACL injuries. Despite the narrative nature of this review, a systematic search for published studies in the last twenty years regarding the most relevant injuries associated with a higher risk of PTOA and associated risk factors for OA was conducted. This review identified the six more relevant injuries associated with knee or hip PTOA. We describe the incidence, risk factors for the injury and risk factors for PTOA of each. Meniscal injury, proximal tibial fracture, patellar dislocation, acetabular, femoral fractures and hip dislocations are all discussed in this review.

Operative strategy for tri-malleolar ankle fractures with posteromedial plafond involvement: a review of sixty six cases

PURPOSE

We aimed to summarize the radiographic and clinical outcomes in various conditions of tri-malleolar ankle fractures (TMFs) with posteromedial (PM) plafond involvement (TMF + PM) and determine the factors affecting their subjective clinical outcomes.

METHODS

Radiographic and clinical findings of 66 patients who underwent operative treatment for TMF + PM were retrospectively reviewed. The patients were classified into three groups according to the PM fracture line location. Type I fractures were defined when the PM fracture line extended medially beyond the PM corner of the distal tibia while type II fractures were those in which the PM fracture line was located laterally to the PM corner. Type III fractures were defined as medial malleolar avulsion fractures when the PM fracture integrated into the medial malleolus. Clinical outcomes were evaluated using a subjective rating scale (excellent, good, fair, poor, and bad). Satisfactory results were defined as excellent, good, and fair. Factors affecting satisfactory clinical outcomes were assessed using a binary logistic regression analysis. Independent variables included demographic, fracture-related, and operation-related factors and radiographic measurements at the final follow-up.

RESULTS

Satisfactory clinical outcomes were observed in 74.2% of the total patients; of these patients, 75.7% (28/37), 76.5% (13/17), and 66.7% (8/12) had type I, type II, and type III fractures, respectively. The binary logistic regression analysis revealed that age at the time of operation, number of incarcerated fragments (IFs), type of IFs, and postoperative articular step-offs (mm) were related to subjective clinical outcomes (all P < 0.05). A positive value for post-operative articular step-offs represented distal migration of the posterior malleolar fragments. The odds ratios for older age, increased numbers of IFs, rotated IFs, and positive articular step-offs were 0.936, 0.116, 0.020, and 0.295, respectively.

CONCLUSION

Because TMF + PM is highly unstable, a delicate approach is needed according to each patient's fracture condition. Although it is best to reduce the fractured articular surface, a negative step-off, rather than a positive step-off, would be more likely recommended if accurate reduction is impossible. This could be applied to manage IFs, especially when the IFs are rotated. Dimpling of the articular surface induced by the removal of a small IF was not related to unsatisfactory clinical outcomes.

Initial description of the TEKTONA® technique for tibial plateau depression fractures

Reduction of depressed tibial plateau fractures with TEKTONA® is a percutaneous technique done with fluoroscopy guidance whose aim is to preserve the soft tissues and avoid hemorrhage. The anatomical result is close to that of open reduction with benefits such as reduced pain and early motion. This procedure was first described for vertebral compression fractures but has recently been applied to intra-articular long bone fractures. It consists of reducing depressed fragments with a system of expandable strips mounted on a rigid clamp. Fixation of the reduced fragments is done with cement; percutaneous fixation can be added. This technique is an interesting alternative to standard treatments. Mastery requires good knowledge of the various steps and comprehensive analysis of the depression on CT scan.

Radiological malunion after ankle fractures in older adults : definitions and new thresholds derived from clinical outcome data from the AIM trial

AIMS

The rationale for exacting restoration of skeletal anatomy after unstable ankle fracture is to improve outcomes by reducing complications from malunion; however, current definitions of malunion lack confirmatory clinical evidence.

METHODS

Radiological (absolute radiological measurements aided by computer software) and clinical (clinical interpretation of radiographs) definitions of malunion were compared within the Ankle Injury Management (AIM) trial cohort, including people aged ≥ 60 years with an unstable ankle fracture. Linear regressions were used to explore the relationship between radiological malunion (RM) at six months and changes in function at three years. Function was assessed with the Olerud-Molander Ankle Score (OMAS), with a minimal clinically important difference set as six points, as per the AIM trial. Piecewise linear models were used to investigate new radiological thresholds which better explain symptom impact on ankle function.

RESULTS

Previously described measures of RM and surgeon opinion of clinically significant malunion (CSM) were shown to be related but with important differences. CSM was more strongly related to outcome (-13.9 points on the OMAS; 95% confidence interval (CI) -21.9 to -5.4) than RM (-5.5 points; 95% CI -9.8 to -1.2). Existing malunion thresholds for talar tilt and tibiofibular clear space were shown to be slightly conservative; new thresholds which better explain function were identified (talar tilt > 2.4°; tibiofibular clear space > 6 mm). Based on this new definition the presence of RM had an impact on function, which was statistically significant, but the clinical significance was uncertain (-9.1 points; 95% CI -13.8 to -4.4). In subsequent analysis, RM of a posterior malleolar fracture was shown to have a statistically significant impact on OMAS change scores, but the clinical significance was uncertain (-11.6 points; 95% CI -21.9 to -0.6).

CONCLUSION

These results provide clinical evidence which supports the previously accepted definitions. Further research to investigate more conservative clinical thresholds for malunion is indicated.Cite this article: Bone Jt Open 2022;3(10):841-849.

Distal Humerus Morphological Analysis of Chinese Individuals: A Statistical Shape Modeling Approach

Objective

A detailed analysis of the morphology of distal humeral articulation can help in the creation of anatomic prostheses of hemiarthroplasty. This study used statistical shape modeling to evaluate the 3D morphology of the distal humerus in healthy Chinese individuals and to investigate the proper articular morphology differences.

Methods

A statistical shape model (SSM) of the distal humerus was created using CT scans of 106 survey‐confirmed nonpathologic elbows. In addition, the articular components of each principal component (PC) were selected and fitted on the mean mode. The Euclidean point‐to‐mesh distance of articular modes was calculated as a measurement the proper change in the morphology of the articulation.

Results

The first seven PCs jointly accounted for 80.9% of the total variation (44.4%, 12.2%, 7.9%, 5.9%, 4.1%, 3.4% and 3%, respectively). In the mean model, the distance between the medial and lateral epicondyles was 57.4 mm, the width of the articulation was 42.1 mm, and the angle of the transepicondylar line (TEL) and C line was 4.8°. The articular surface differences of the first PC were significant (RMS: 1.43 mm in the −3 SD model and 2.38 mm in the +3 SD model), whereas under other conditions, the differences were not remarkable despite the maximum deformation not exceeding 1 mm.

Conclusion

A novel method (SSM) was used to evaluate the 3D morphology of the distal humerus in healthy Chinese individuals and investigate the proper articular shape differences. We found the proper shape of articular surface basically transformed into one variation pattern which was relevant to the bone size, even though the morphology of distal humerus possessed complicated variation modes. The findings of this study can be helpful to design the next generation of elbow hemiarthroplasty in the future.

Percutaneous surgery with balloon for tibial plateau fractures, results with a minimum of 5 years of follow-up

Tibial plateau fracture is a frequent entity for which surgical management is difficult both surgically and postoperatively, with multiple complications and often delayed recovery. The challenge lies in the anatomical reduction of the joint, the limitation of complications and the rapid functional recovery. Tuberoplasty appears to be an innovative technique that meets current expectations. The objective is to evaluate the reliability of tuberoplasty in reducing surgical risks and improving postoperative clinical results. This single-centre retrospective study included 30 patients with depressed tibial plateau fractures who underwent tuberoplasty from September 2011 to March 2014. Reduction analysis was performed by comparing pre-operative and post-operative depression from computed tomography (CT) data. Clinical outcomes were assessed by measuring flexion joint ranges, time to weight-bearing, KOOS questionnaire and a pangonogram. The mean depression was 7.4mm pre-operatively and 2.6mm [0;9] post-operatively, with 47% (14/30) having a residual depression of 2mm or less. Mean flexion at 6 weeks was 103° [30; 130]. Partial and total weight-bearing were allowed on day 47 [3; 150] and day 58 [20; 150], respectively. The mean KOOS score was 25.43 [1.15; 62.30] at a minimum of 5 years after surgery and the mean axis was 176.54° [172; 180]. There was one case of thrombophlebitis and one sensory-motor deficit in the common fibular nerve territory. The reduction of the tibial plateau observed in our study from tuberoplasty is in line with the literature results obtained from a conventional approach. Our results indicate that tuberoplasty is stable in the long term, has good functional results and early recovery with few complications. This preliminary study presents results that need to be investigated in a prospective randomised double-blind study.

Vertical Patella Fracture Fixed by Plate and Screws With Bone Graft: A Case Report

Fractures of the patella constitute approximately 1% of all skeletal injuries. The vertical pattern represents 12-17% and the open patella fracture represents 6-30%. We here represent a rare case constituting the presence of these two uncommon (vertical type patella fracture with depression of articular surface). A 22-year-old male had a close patella fracture after a road traffic accident. The fracture was classified as a vertical and comminuted pattern. A back slab above the knee was applied and then the patient was prepared for surgery. Open reduction and internal fixation of the patella by miniplate and bone graft restore the articular surface, which reduces the risk of post-traumatic osteoarthritis. At five months postoperatively, the patient had a satisfactory joint motion with full extension and 120° of joint flexion and returned to his daily life activities without restriction. Additionally, the patient was in good health and able to bear full weight. In conclusion, the treatment choice requires a thorough knowledge of the case to ensure good stability and avoid fracture displacement.

Revisiting the management of tibial plateau fractures

Three-dimensional imaging has changed the understanding and management of tibial plateau fractures. In the 1970s, Schatzker proposed a classification for tibial plateau fractures, which highlighted the morphology of the six principal types. More recently, this original classification was complimented by an extended one underscoring the importance of understanding where the split wedge fragment(s) is/are located in three dimensions. The extended classification introduced the split wedge fragment and the continuity of the rim as the determinants of joint stability and the critical role that this plays in the management of tibial plateau fractures. The current manuscript re-emphasizes contemporary concepts of tibial plateau stability and depicts key issues which must be considered when planning the definitive surgical fixation of tibial plateau fractures.

Combination of Lidocaine and IL-1Ra Is Effective at Reducing Degradation of Porcine Cartilage Explants

BACKGROUND

Posttraumatic inflammation after joint injury, ranging from sprains to articular fracture, contributes to the development of arthritis, and the administration of interleukin 1 (IL-1) receptor antagonist (IL-1Ra) is a potential intervention to mitigate this response. Although IL-1Ra mitigates cartilage degenerative changes induced by IL-1, lidocaine is used for local pain management in acute joint injury. Intra-articular delivery of both drugs in combination would be a novel and possibly disease-modifying treatment. However, it is not known whether the interaction with lidocaine at clinical concentrations (1%) would alter the efficacy of IL-1Ra to protect cartilage from the catabolic effects of IL-1.

HYPOTHESIS

Treatment of articular cartilage with IL-1Ra in combination with a clinically relevant concentration of lidocaine (1%) will inhibit the catabolic effects of IL-1α in a manner similar to treatment with IL-1Ra alone.

STUDY DESIGN

Controlled laboratory study.

METHODS

Fresh porcine cartilage explants were harvested, challenged with IL-1α, and incubated for 72 hours with IL-1Ra or a combination of IL-1Ra and lidocaine. The primary outcome was total sulfated glycosaminoglycan (sGAG) release. Additional experiments assessed the effect of storage temperature and premixing of IL-1Ra and lidocaine on sGAG release. All explants were histologically assessed for cartilage degradation using a modified Mankin grading scale.

RESULTS

The combination of IL-1Ra and lidocaine, premixed at various time points and stored at room temperature or 4°C, was as effective as IL-1Ra alone at inhibiting IL-1α-mediated sGAG release. Mankin histopathology scores supported these findings.

CONCLUSION

Our hypothesis was supported, and results indicated that the combination of IL-1Ra and lidocaine was as efficacious as IL-1Ra treatment alone in acutely mitigating biological cartilage injury due to IL-1α in an explant model.

CLINICAL SIGNIFICANCE

The combination of IL-1Ra and lidocaine is stable when reagents are stored in advance of administration at varying temperatures, providing clinically relevant information about storage of medications. The ability to premix and store this drug combination for intra-articular delivery may provide a novel treatment after joint injury to provide pain relief and block inflammation-induced catabolism of joint tissues.

Elderly unstable distal radius fractures a prospective cohort study of bone substitutes-augmented percutaneous pinning

Background

Based on debatable recommendations of using bone substitutes for filling of metaphyseal void in elderly unstable distal radius fractures; this study investigated the following question “Do bone substitutes effectively contribute to postoperative stability of k-wire fixation construct and accelerate healing in elderly unstable distal radius fractures?”.

Methods

This prospective cohort study was conducted from October 2014 to April 2021. According to use of bone substitutes, 40 patients of elderly unstable distal radius fractures were alternately allocated into; group-(A) of bone substitutes-augmented percutaneous pinning (19 patients); and group-(B) of non-augmented percutaneous pinning (21 patients). Groups were compared for preoperative patients’ demographics and postoperative ROM, Quick-DASH and Mayo Wrist scores, radiographic parameters (palmar tilt, radial height and inclination, ulnar variance and intra-articular step-off) and duration until radiographic fracture healing.

Results

Statistically, augmented and non-augmented groups were matched in terms of patients’ demographics (mean age; 58.7 vs. 62.0 years respectively, P-value = 0.25). All included fractures have healed with insignificantly longer duration in augmented group (7.1 vs. 6.8 weeks, P-value = 0.26). At 12-week postoperative evaluation, radiographic parameters of both groups were comparably well-maintained except for intra-articular step-off which showed significantly less secondary displacement in augmented group (0.1 vs. 0.4 mm, P-value = 0.01). There were insignificant differences in 6-month postoperative ROM, and Quick-DASH and Mayo Wrist scores.

Conclusion

Compared to its bone substitutes-augmented counterpart; non-augmented percutaneous pinning of elderly unstable distal radius fractures can offer advantages of comparable healing rates and functional and radiographic outcomes, less-invasive approach, shorter operative time and lower cost.

Level of evidence

III

When used to augment percutaneous pinning of elderly unstable distal radius fractures, bone substitutes did not significantly offer additional postoperative mechanical stability of fixation construct.

When used to augment percutaneous pinning of elderly unstable distal radius fractures, bone substitutes did not significantly accelerate fracture healing.

Compared to bone substitutes-augmented pinning; stand-alone percutaneous pinning of elderly unstable distal radius fractures can achieve comparable healing rates and satisfactory functional and radiographic outcomes; and in addition, less-invasive approach, shorter operative time and lower cost.

Intra-Articular Synovial Fluid With Hematoma After Ankle Fracture Promotes Cartilage Damage In Vitro Partially Attenuated by Anti-Inflammatory Agents

BACKGROUND

Intra-articular ankle fracture (IAF) causes posttraumatic osteoarthritis (PTOA), but the exact mechanism is unknown. Proinflammatory mediators have been shown to be present in the synovial fluid fracture hematoma (SFFH) but have not been linked to cartilage damage. The purpose of this study was to determine if the SFFH causes cartilage damage and whether this damage can be attenuated by commercially available therapeutic agents.

METHODS

Synovial fluid was obtained from 54 IAFs and cultured with cartilage discs from the dome of fresh allograft human tali and randomly assigned to one of the following groups: (A) control-media only, (B) SFFH from days 0 to 2 after fracture, (C) SFFH from days 3 to 9, (D) SFFH from days 10 to 14, (E) group B + interleukin 1 receptor antagonist (IL-1Ra), and (F) group B + doxycycline. The cartilage discs underwent histological evaluation for cell survival and cartilage matrix components. The spent media were analyzed for inflammatory mediators.

RESULTS

Cartilage discs cultured with SFFH in groups B, C, and D demonstrated significantly increased production of cytokines, metalloproteinases (MMPs), and extracellular matrix breakdown products. Safranin O staining was significantly decreased in group B. The negative effects on cartilage were partially attenuated with the addition of either IL-1RA or doxycycline. There was no difference in chondrocyte survival among the groups.

CONCLUSION

Exposure of uninjured cartilage to IAF SFFH caused activation of cartilage damage pathways evident through cartilage disc secretion of inflammatory cytokines, MMPs, and cartilage matrix fragments. The addition of IL-1Ra or doxycycline to SFFH culture partially attenuated this response.

CLINICAL RELEVANCE

IAFs create an adverse intra-articular environment consisting of significantly increased levels of inflammatory cytokines and MMPs able to damage cartilage throughout the joint. These data suggest that the acute addition of specific inflammatory inhibitors may decrease the levels of these proinflammatory mediators.

A lateral fracture step-off of 2mm increases intra-articular pressure following tibial plateau fracture

INTRODUCTION

The aim of this study was to evaluate the effects of increasing posttraumatic step-offs after lateral tibial plateau fracture reduction on the intra-articular pressure.

MATERIALS AND METHODS

In eight fresh-frozen human cadaveric knees with intact menisci, a standardized sagittal osteotomy of the lateral tibial condyle was performed as an OTA/AO type 41-B1 fracture-model. The fragment was fixed by a customized sled including an angular stable tibia plate to evaluate step-offs from 0 mm to 8 mm in 1mm increments. In a servo-hydraulic testing machine, an axial force was applied to the tibial plateau in 0° (700N), 15° (700N), 30° (700N), 60° (350N), and 90 ° (350N) of flexion while the joint pressure was recorded by two pressure sensors.

RESULTS

A 1mm step-off did not result in an increased joint pressure. At 60° of flexion a 2mm step-off increased the lateral joint pressure by 61.84kPa (P = 0.0027). In 30° of flexion, a 3mm step raised the lateral joint pressure by 66.80kPa (p = 0.0017), whereas in 0°, 15° and 90° of flexion, a 4mm step increased the pressure by >50kPa (P < 0.05). Concomitant medial joint pressure increments were lower than those in the lateral plateau. A significant increase of 19-24kPa in the medial joint pressure was detected in 90° of flexion with a 1mm lateral step (P = 0.0075), in 15° and 60° of flexion with a 2mm step (P < 0.05), in 0° of flexion with a 4mm step (P = 0.0215) and in 30° of flexion with a 7mm step (P = 0.0487).

CONCLUSION

Lateral fracture step-offs of 2mm or larger should be reduced intraoperatively to avoid large increases in lateral joint pressure.

Analysis of Our Open Reduction and Internal Fixation of Distal Radius Fractures in Adults: Are We Over Operating?

Background  Fractures of the distal radius are a common injury. The British Orthopaedic Association (BOA) and The British Society for Surgery of the Hand (BSSH) have released new guidelines outlining the management of these fractures, specifically identifying "thresholds for intervention," based on radiological parameters for management with open reduction and internal fixation (ORIF). Questions/Purposes  Have our distal radius fractures (DRFs), previously managed with ORIF, met the new guidelines' thresholds for intervention, based on radiological parameters? Patients and Methods  A retrospective assessment of DRFs treated with ORIF was performed between January 2017 and August 2018. Patients were categorized into three cohorts based on their age. The five radiological parameters of ulnar variance, dorsal tilt, radial inclination, radial height, and intra-articular step were measured on the initial plain radiograph, "pre-manipulation film," postplaster application radiograph, and "post-manipulation film." These were compared with the "thresholds for intervention" outlined in the BOA/BSSH guidelines. Results  A total of 94 patients underwent an ORIF with a mean age of 56 years (range 17-86 years). As many as 75.74% of patients on the "pre-manipulation film" met the "threshold for intervention" on at least one radiological parameter, while 53.57% of patients on the "post-manipulation" met at least one "threshold for intervention." Dorsal tilt was the parameter that most often met the threshold in both films at 53.37% and 40.11%, respectively. Conclusion  Within our trust, there is a tendency to over manage the distal radius fracture with ORIF, potentially resulting in unnecessary operations. Education surrounding the new guidelines will better serve our decision-making. Level of Evidence  This is a level III study.

Standard versus customised locking plates for fixation of schatzker ii tibial plateau fractures

AIM

3D-printed implants could improve the capture of fracture fragments for improved stability of tibial plateau fracture fixation. The aim of this study was to compare the biomechanical strength of fixation constructs using standard and customised 3D-printed proximal tibial locking plates for fixation of tibial plateau fractures.

METHODS

This is a biomechanical study utilising six pairs of cadaveric tibiae. Fractures were created in an identical fashion using an osteotome and mallet, and fixed using either a standard, commercially-available proximal tibia locking plate or a customised 3D-printed plate. Design and production of the customised plates followed a "3D printing at point-of-care" model. Customised stainless steel 316 L plates were produced within a local additive manufacturing laboratory based upon pre-operative CT scans. Determination of implant choice within each cadaver pair was performed via simple randomisation. Following fracture fixation, the tibiae were skeletalised and biomechanically tested using a customised loading jig and a size-matched femoral knee prosthesis. The constructs were loaded cyclically from 100 N to approximately three times the cadaveric body-weight at 5 Hz for 10 000 cycles. Every 1000 cycles, the test was paused and the tibia was physically checked for failure. If failure had not occurred by the end of the testing cycle, the construct was loaded to failure and the load at which the construct failed was noted.

RESULTS

Fixation constructs using the 3D-printed plates performed comparably to those using the standard plates. There was no significant difference in the degree of fracture fragment displacement in both constructs. Overall longitudinal construct stiffness and load to failure was higher in the 3D-plates group but this did not reach statistical significance.

CONCLUSION

Production of customised plates for proximal tibia fractures at point-of-care is feasible, however fixation constructs with these plates did not provide any biomechanical advantage over standard plates in terms of axial loading stiffness.

Radiological and Functional Assessment of Treatment Outcomes in Patients after Open Reduction with Internal Fixation (ORIF) of Acetabular Fractures

(1) Fracture of the pelvis usually happens in young men and results from high-energy trauma. It generates high social and economic costs and results in further health problems. It is therefore important to assess long-term treatment results. (2) The study (NCT04902209) involved 31 patients (mean age 43.6 ± 14.8 years). We conducted fixation assessment on the basis of radiographs and CT scans and functional assessment based on functional scales. (3) We observed more degenerative changes in the less precise reconstruction of the acetabulum (p = 0.075). We did not find statistically significant relationships between the area of surgical approach, the gravity of fracture, and the development of degenerative changes. We did not find statistically significant relationships between patients' functional states and the type of surgical approach or the complexity of the fracture. We found a positive correlation between the time of surgical treatment and patients' functional state (p = 0.04). Patients whose joint surfaces were reconstructed anatomically had significantly higher scores in functional scales (HHS p = 0.05, Merle p = 0.03). (4) Patients after surgical fixation of the acetabulum have low functional abilities. The quality of reconstruction of the loaded surface as well as the length of time post-surgery seems to be essential for the patients' functional state.

Does Time to Theatre Affect the Ability to Achieve Fracture Reduction in Tibial Plateau Fractures?

Surgical management of displaced tibial plateau fracture (TPF) is often delayed due to accompanying soft tissue injuries sustained at the time of injury. The primary aim of this study was to assess the effect of time to surgery on fracture reduction in cases of TPF. The secondary aim was to assess the effect of preoperative demographics and residual articular step on Lysholm Scores and Knee Injury and Osteoarthritis Outcome Scores (KOOS) following fixation. Patients between 2006 and 2017, managed by a single surgeon, were prospectively enrolled in the study. Reduction of articular step, defined as <2 mm, was assessed by a single blinded examiner. A total of 117 patients were enrolled, 52 with Schatzker II, 4 with Schatzker IV, and 61 with Schatzker VI fractures. Patients were followed up to a mean of 3.9 years. Analysis showed that the ability to achieve fracture reduction was negatively influenced by time to theatre, with the odds of achieving reduction decreasing 17% with each subsequent day post injury (p = 0.002). Furthermore, an increased time to theatre was associated with a reduced Lysholm score at one year (p = 0.01). The ability to achieve fracture reduction did not influence PROMs within the study period. We conclude that delay in surgical fixation negatively affects fracture reduction in TPF and may delay recovery. However, residual articular step does not necessarily influence PROMs over the mid-term.

The Tibial Plateau Map: Fracture Line Morphology of Intra-Articular Proximal Tibial Fractures

The purpose of this study was to characterize the patterns of a large series of tibial plateau fractures with the use of fracture mapping, with regard to different fracture types using the OTA/AO and Schatzker classification. Patients with intra-articular fractures of the tibial plateau were evaluated, using the OTA/AO and Schatzker classification on CT scans. For fracture mapping, the axial slice that completely displayed the tibial joint plane was first identified, then matched to a template congruently, and the fracture lines were identified and reproduced. In addition to epidemiological data (age and gender), the trauma mechanism (high-energy, low-energy, and pathological fracture) was recorded. In total, 271 patients with 278 intra-articular fractures of the tibial head were analyzed, including seven patients with both sides affected. The mean age was 49.1 years (men 46.3 years, women 53.5 years). The majority of fractures was caused by high-energy trauma. No significant difference could be shown with respect to trauma mechanism and resulting fracture type in terms of OTA/AO (p = 0.352) or Schatzker classification (p = 0.884). A significant difference could be found with respect to gender and resulting fracture type in terms of OTA/AO (p = 0.031). 170 (61.2%) were OTA/AO type B fractures, and 108 (38.8%) were type C fractures. Using the Schatzker classification, we found 53 type I (19.1%), 60 type II (21.6%), 27 type III (9.7%), 32 type IV (11.5%), 16 type V (5.8%), and 90 type VI (32.4%) fractures. The main affection was found in the lateral and intermedial column of the tibial plateaus, concerning both OTA/AO and Schatzker classification. The variability of intra-articular tibial head fractures is very high. In consequence, an individual analysis of fracture patterns and therapy planning by using CT scans is crucial.

Origins of the threshold for surgical intervention in intra-articular distal radius fractures

AIMS

The aim of this study was to identify the origin and development of the threshold for surgical intervention, highlight the consequences of residual displacement, and justify the importance of accurate measurement.

METHODS

A systematic review of three databases was performed to establish the origin and adaptations of the threshold, with papers screened and relevant citations reviewed. This search identified papers investigating functional outcome, including presence of arthritis, following injury. Orthopaedic textbooks were reviewed to ensure no earlier mention of the threshold was present.

RESULTS

Knirk and Jupiter (1986) were the first to quantify a threshold, with all their patients developing arthritis with > 2 mm displacement. Some papers have discussed using 1 mm, although 2 mm is most widely reported. Current guidance from the British Society for Surgery of the Hand and a Delphi panel support 2 mm as an appropriate value. Although this paper is still widely cited, the authors published a re-examination of the data showing methodological flaws which is not as widely reported. They claim their conclusions are still relevant today; however, radiological arthritis does not correlate with the clinical presentation. Function following injury has been shown to be equivalent to an uninjured population, with arthritis progressing slowly or not at all. Joint space narrowing has also been shown to often be benign.

CONCLUSION

Knirk and Jupiter originated the threshold value of 2 mm. The lack of correlation between the radiological and clinical presentations warrants further modern investigation. Measurement often varies between observers, calling a threshold concept into question and showing the need for further development in this area. The principle of treatment remains restoration of normal anatomical position. Cite this article: Bone Joint J 2021;103-B(9):1457-1461.

Initial displacement of the intra-articular surface after articular fracture correlates with PTA in C57BL/6 mice but not "superhealer" MRL/MpJ mice

Posttraumatic arthritis (PTA) occurs commonly after articular fracture and may arise, in part, from joint surface incongruity after injury. MRL/MpJ (MRL) "super-healer" mice are protected from PTA compared to C57BL/6 (B6) mice following articular fracture. However, the relationship between the initial displacement of the articular surface, biologic response, and susceptibility to PTA after fracture remains unclear. The objective of this study was to assess whether joint incongruity after articular fracture, as measured by in vivo micro-computed tomography (microCT), could predict pathomechanisms of PTA in mice. B6 and MRL mice (n = 12/strain) received a closed articular fracture (fx) of the left tibial plateau. Articular incongruity was quantified as bone surface deviations (BSD) for each in vivo microCT scan obtained from pre-fx to 8 weeks post-fx, followed by histologic assessment of arthritis. Serum concentrations of bone formation (PINP) and bone resorption (CTX-I) biomarkers were quantified longitudinally. Both strains showed increases in surface incongruity over time, as measured by increases in BSD. In B6 mice, acute surface incongruity was significantly correlated to the severity of PTA (R ²  = 0.988; p = .0006), but not in MRL mice (R ²  = 0.224; p = .220). PINP concentrations significantly decreased immediately post-fx in B6 mice (p = .023) but not in MRL mice, indicating higher bone synthesis in MRL mice. MRL/MpJ mice demonstrate a unique biologic response to articular fracture such that the observed articular bone surface displacement does not correlate with the severity of subsequent PTA. Clinical Relevance: Identifying therapies to enhance acute biologic repair following articular fracture may mitigate the risk of articular surface displacement for PTA.

Medial sided articular impaction in tibial plateau fractures

INTRODUCTION

Tibial plateau fractures are a heterogenous group of injuries with a variable amount of articular injury and are commonly associated with lateral sided articular impaction. Previous work has focused on describing the morphology of tibial plateau fractures, but has neglected description of medial sided articular impaction. The aim of this investigation was to assess the morphology of medial sided articular impaction in tibial plateau fractures, with specific attention directed toward the frequency, location, size, and associated fracture patterns.

METHODS

Skeletally mature patients presenting to a Level I trauma center from 2008-2018 with a tibial plateau fracture (AO/OTA 41B-C) were identified retrospectively. Fractures were classified by AO/OTA and Schatzker type. Radiographs and computed tomography (CT) scans were reviewed to identify and localize medial sided articular impaction. The location and surface area of impaction was characterized by creating frequency diagram heat maps from axial CT scans. Descriptive statistics were performed using standard measures.

RESULTS

Of the 1032 tibial plateau fractures included, 82 (7.9%) were noted to have medial sided articular impaction. Rate of impaction varied by fracture type (p = 0.03): Schatzker II, 2% (7 of 381); Schatzker IV, 21% (19 of 96); and Schatzker VI, 11% (56 of 524). Average total surface area of impaction was 9% of the total and 19% of the medial plateau area. Area of impaction varied by fracture type (p = 0.004): Schatzker II, 6% (95% confidence interval [CI], 4%-7%); Schatzker IV, 11% (95% CI, 9%-13%), and Schatzker VI, 9% (95% CI, 7%-11%). The area of impaction occurred primarily along the lateral aspect of the medial plateau in Schatzker II fractures, in the anteromedial quadrant of Schatzker IV fractures, and was evenly distributed across the medial plateau in Schatzker VI fractures.

CONCLUSIONS

Surgeons should be aware that medial articular impaction is present in approximately 8% of tibial plateau fractures. Schatzker IV fractures are most likely to have medial impaction and a larger proportion of the joint surface involved in these injuries.

Exploring partial intrinsic and extrinsic symmetry in 3D medical imaging

We present a novel methodology to detect imperfect bilateral symmetry in CT of human anatomy. In this paper, the structurally symmetric nature of the pelvic bone is explored and is used to provide interventional image augmentation for treatment of unilateral fractures in patients with traumatic injuries. The mathematical basis of our solution is based on the incorporation of attributes and characteristics that satisfy the properties of intrinsic and extrinsic symmetry and are robust to outliers. In the first step, feature points that satisfy intrinsic symmetry are automatically detected in the Möbius space defined on the CT data. These features are then pruned via a two-stage RANSAC to attain correspondences that satisfy also the extrinsic symmetry. Then, a disparity function based on Tukey's biweight robust estimator is introduced and minimized to identify a symmetry plane parametrization that yields maximum contralateral similarity. Finally, a novel regularization term is introduced to enhance similarity between bone density histograms across the partial symmetry plane, relying on the important biological observation that, even if injured, the dislocated bone segments remain within the body. Our extensive evaluations on various cases of common fracture types demonstrate the validity of the novel concepts and the accuracy of the proposed method.

Immune cell profiling in the joint following human and murine articular fracture

OBJECTIVE

Human and in vivo animal research implicates inflammation following articular fracture as contributing to post-traumatic arthritis. However, relevant immune cell subsets present following injury are currently undefined. Immunophenotyping human and murine synovial fluid may help to identify immune cell populations that play key roles in the response to articular fracture.

METHODS

Immunophenotyping by polychromatic flow cytometry was performed on human and mouse synovial fluid following articular fracture. Specimens were collected in patients with closed ankle fracture at the time of surgical fixation and from C57BL/6 mice with closed articular knee fracture. Immune cells were collected from injured and uninjured joints in mice via a novel cell isolation method. Whole blood samples were also collected. Immunohistochemistry (IHC) was performed on mouse synovial tissue to assess for macrophages and T cells.

RESULTS

Following intra-articular fracture, the prominent human synovial fluid immune cell subset was CD3+ T cells, containing both CD4+ and CD8+ T cells. In mice, infiltration of CD45+ immune cells in synovial fluid of the fractured limb was dominated by CD19+ B cells and CD3+ T cells at 7 days after intra-articular fracture. We also detected adaptive immune cells, including macrophages, NK cells, dendritic cells and monocytes. Macrophage and T cell findings were supported by IHC of murine synovial tissue.

CONCLUSIONS

Determining specific cell populations that mediate the immune response is essential to elucidating the chain of events initiated after injury and may be an important step in identifying potential immune signatures predictive of PTA susceptibility or potential therapeutic targets.