CT of Periarticular Adult Knee Fractures: Classification and Management Implications.

Periarticular knee fractures, which include fractures of the distal femur, tibial plateau, and patella, account for 5%-10% of musculoskeletal injuries encountered in trauma centers and emergency rooms. These injuries are frequently complex, with articular surface involvement. Surgical principles center on reconstruction of the articular surface as well as restoration of limb length, alignment, and rotation to reestablish functional knee biomechanics. Fixation principles are guided by fracture morphology, and thus, CT with multiplanar reformats and volume rendering is routinely used to help plan surgical intervention. Fractures involving the distal femur, tibial plateau, and patella have distinct management considerations. This comprehensive CT primer of periarticular knee fractures promotes succinct and clinically relevant reporting as well as optimized communication with orthopedic trauma surgeon colleagues by tying fracture type and key CT findings with surgical decision making. Fracture patterns are presented within commonly employed fracture classification systems, rooted in specific biomechanical principles. Fracture typing of distal femur fractures and patellar fractures is performed using Arbeitsgemeinschaft für Osteosynthesefragen/Orthopedic Trauma Association (AO/OTA) classification schemes. Tibial plateau fractures are graded using the Schatzker system, informed by a newer explicitly CT-based three-column concept. For each anatomic region, the fracture pattern helps determine the surgical access required, whether bone grafting is warranted, and the choice of hardware that achieves suitable functional outcomes while minimizing the risk of articular collapse and accelerated osteoarthritis. Emphasis is also placed on recognizing bony avulsive patterns that suggest ligament injury to help guide stress testing in the early acute period. ©RSNA, 2024 Supplemental material is available for this article.

Determination of the ideal plate for medial femoral condyle fracture fixation: an anatomical fit and biomechanical study.

BACKGROUND: The aim of this study is to determine the best plate to use as a substitute to fix a medial femoral condyle fracture. MATERIALS AND METHODS: The first part is to measure the best fit between several anatomical plates including the Proximal Tibia Anterolateral Plate (PT AL LCP), the Proximal Tibia Medial Plate (PT M LCP), the Distal Tibia Medial Locking Plate (DT M LCP) and the Proximal Humerus (PHILOS) plate against 28 freshly embalmed cadaveric distal femurs. Measurements such as plate offset and number of screws in the condyle and shaft shall be obtained. The subsequent part is to determine the compressive force at which the plate fails. After creating an iatrogenic medial condyle fracture, the cadavers will be fixed with the two plates with the best anatomical fit and subjected to a compression force using a hydraulic press. RESULTS: The PT AL LCP offered the best anatomical fit whereas the PHILOS plate offered the maximal number of screws inserted. The force required to create 2 mm of fracture displacement between the two is not statistically significant (LCP 889 N, PHILOS 947 N, p = 0.39). The PT AL LCP can withstand a larger fracture displacement than the PHILOS (LCP 24.4 mm, PHILOS 17.4 mm, p = 0.004). DISCUSSION AND CONCLUSION: Both the PT AL LCP and the PHILOS remain good options in fixing a medial femoral condyle fracture. Between the two, we would recommend the PT AL LCP as the slightly superior option.

Risk and Epidemiology of Periprosthetic Knee Fractures After Primary Total Knee Arthroplasty: A Nationwide Cohort Study.

BACKGROUND: Periprosthetic knee fractures (PPKFs) following total knee arthroplasty (TKA) are uncommon, but potentially serious injuries. We analyze the risk and risk factors for a PPKF in standard primary TKA patients who have osteoarthritis and a minimally (cruciate-retaining TKAs without a femoral box cut) or posterior-stabilized TKA. In addition, we report the risk for patients who have other underlying knee disorders and/or a higher level of TKA constraint. METHODS: All primary TKAs were identified from the Danish National Patient Register and the Danish Knee Arthroplasty Register using data between 1997 and 2022. Subsequent fractures were identified through the International Classification of Diseases diagnosis code, Nordic Medico-Statistical Committee procedure code, or indication for revision TKA. RESULTS: We included 120,642 standard primary TKA patients who had 1,659 PPKFs. The cumulated proportions were 0.4% (95% confidence interval (CI) 0.3 to 0.4) at 2 years 0.8% (0.7 to 0.8) at 5 years. At 10 years, the cumulated proportion was 1.7% (1.6 to 1.8), with 1.3% in the femur, 0.2% in the patella, and 0.2% in the tibia. Significant risk factors were (hazard ratio [HR] [95% CI]); ipsilateral hip arthroplasty (2.3 [2.0 to 2.6]); women (2.1 [1.8 to 2.4]), osteoporosis (1.4 [1.2 to 1.7]); age 80+ (1.4 [1.3 to 1.6]), uncemented TKA (1.3 (1.1 to 1.5) and Charlson Comorbidity Index score 3+ (1.4 [1.1 to 1.8]). An additional 22,624 primary TKA patients who had other underlying knee disorders and/or a higher level of implant constraint were included with 633 PPKFs. The 10-year cumulated proportions were 8.3% (95% CI 6.9 to 9.8) when the underlying disorder was a previous fracture, 2.8% (2.2 to 3.5) for rheumatic disorders, and 5.2% (2.6 to 10.6) for osteonecrosis. In patients who had condylar constrained knees, it was 6.9% (5.1 to 9.4), and 12.4% (8.0 to 16.04) for hinges. CONCLUSIONS: In standard primary TKA patients, the 10-year cumulated proportion of PPKFs was 1.7%, and ipsilateral hip arthroplasty, women, osteoporosis, advanced age, uncemented TKA and higher Charlson Comorbidity Index increased the risk. Higher risks were observed in non-osteoarthritis patients and/or patients who had a higher level of TKA constraint.

Mosaicplasty With High Tibial Osteotomy for Knee Subchondral Insufficiency Fracture Had Better Magnetic Resonance Observation of Cartilage Repair Tissue Scores With Less Bone Marrow Edema and Better Plug Union and Less Plug Necrosis Compared With Mosaicplasty Alone.

PURPOSE: To determine the magnetic resonance imaging (MRI) findings after mosaicplasty (MOS) for knee subchondral insufficiency fracture (SIFK), and to analyze the relationship between MRI findings and clinical outcomes. METHODS: We retrospectively reviewed the cases of consecutive patients who underwent MOS for SIFK with/without high tibial osteotomy (HTO) between January 1998 and December 2015. The MRI findings at 12 months after the surgery were assessed by the modified magnetic resonance observation of cartilage repair tissue (MOCART) score to determine the degree of bone marrow edema (BME), plug union, and plug necrosis. The clinical outcomes were assessed by Lysholm score to clarify the minimal clinically important difference (MCID) and patient acceptable symptom state analysis. RESULTS: In total, 58 patients (17 men and 41 women) were enrolled in this study. Among them, 30 knees were treated by MOS alone and 28 knees were treated by MOS with HTO. The MOCART scores of patients who received MOS alone were significantly lower in BME score (P = .0060), plug union score (P = .0216), and in plug necrosis score (P = .0326) than patients who received MOS with HTO. BME lesion was less likely to persist among elderly (odds ratio 1.20, P = .0248) and female (OR 41.8, P = .0118) patients. The MCID of Lysholm score was 6.6 in MOS alone and 8.4 in MOS with HTO cases, but there were no significant association between MRI findings and the postoperative Lysholm score. CONCLUSIONS: The MOS with HTO cases had better MOCART scores with less BME, better plug union, and less plug necrosis compared with MOS alone cases. Female and older patients had better resolution of BME, but there was no significant correlation between MRI findings and the postoperative Lysholm score. All cases in both groups showed improvement of Lysholm score exceeding MCID; thus, MOS may be effective as a joint preserving surgery for SIFK. LEVEL OF EVIDENCE: Level IV, clinical case series.

Editorial Commentary: Spontaneous Insufficiency Fracture of the Knee, Formerly Known as Spontaneous Osteonecrosis of the Knee, May Benefit From Combined Mosaicplasty and High Tibial Osteotomy: Better Together.

Spontaneous insufficiency fracture of the knee (SIFK) previously termed spontaneous osteonecrosis of the knee (SONK) is a painful knee condition that can occur spontaneously from unknown causes. Histology confirms that a subchondral insufficiency fracture is the true finding and osteonecrosis is a secondary and end-stage finding of the SIFK spectrum of disease. SIFK demonstrates a subchondral fracture and bone marrow edema (BME) on MRI and if left untreated, it can lead to collapse. SONK is most often diagnosed in middle-aged and older patients and is more common in females. It is usually found in the medial femoral condyle. Approximately one-third of patients progressed to total knee arthroplasty. Factors that contributed to disease progression included baseline arthritis, older age, location of the insufficiency fracture, meniscal extrusion, and varus malalignment. Positive outcomes have been reported when SIFK is treated with a combination of mosaicplasty (MOS) and high tibial osteotomy (HTO). And just as like MOS and HTO work better together, we need to collaborate to find solutions. We too are better together.

Arthroscopic percutaneous pullout suture transverse tunnel technique repair for tibial spine fractures in skeletally immature patients.

PURPOSE: We introduce an arthroscopic percutaneous pullout suture transverse tunnel (PP-STT) technique for repair tibial spine fractures (TSF) in skeletally immature patients (SIPs) to avoid damage to the tibial epiphyseal and evaluate the clinical and radiological outcomes of the PP-STT technique for repair TSF in SIPs. METHODS: Between February 2013 and November 2019, 41 skeletally immature patients were diagnosed with TSF; 21 patients were treated using the conventional transtibial pullout suture (TS-PLS) technique (group 1), and 20 patients were treated using the PP-STT technique (group 2). We compared clinical outcomes using the International Knee Documentation Committee (IKDC), Lysholm, Tegner, and visual analog scale (VAS) scores and participant sport levels, after a minimum of two year follow-up. Residual knee laxity was evaluated using Lachman and anterior drawer tests. Fracture healing and displacement were compared using X-ray. RESULTS: Significant improvements in clinical and radiological outcomes between preoperative and final follow-up (Lysholm, Tegner, IKDC, and VAS scores; Lachman and anterior drawer tests; and fracture displacement; p = 0.001) were achieved in both groups, with no significant between-group differences. Groups 1 and 2 exhibited no significant difference in time to radiographic healing (12.2 ± 1.3 weeks vs 13.1 ± 1.5 weeks, respectively; p = 0.513) or in the rate of return to sports level (19 (90.4%) vs 18 (90.0%), respectively; p = 0.826). CONCLUSION: Both surgical techniques provided satisfactory clinical and radiological outcomes. PP-STT may be a suitable alternative to protect the tibial epiphyseal for repair TSP in SIPs.

Meniscal injuries in skeletally immature children with tibial eminence fractures. Systematic review of literature.

PURPOSE: Although the mechanisms of injury are similar to ACL rupture in adults, publications dealing with meniscal lesions resulting from fractures of the intercondylar eminence in children are much rarer. The main objective was to measure the frequency of meniscal lesions associated with tibial eminence fractures in children. The second question was to determine whether there is any available evidence on association between meniscal tears diagnostic method, and frequencies of total lesions, total meniscal lesions, and total entrapments. METHODS: A comprehensive literature search was performed using PubMed and Scopus. Articles were eligible for inclusion if they reported data on intercondylar tibial fracture, or tibial spine fracture, or tibial eminence fracture, or intercondylar eminence fracture. Article selection was performed in accordance with the PRISMA guidelines. RESULTS: In total, 789 studies were identified by the literature search. At the end of the process, 26 studies were included in the final review. This systematic review identified 18.1% rate of meniscal tears and 20.1% rate of meniscal or IML entrapments during intercondylar eminence fractures. Proportion of total entrapments was significantly different between groups (17.8% in the arthroscopy group vs. 6.2% in the MRI group; p < .0001). Also, we found 20.9% of total associated lesions in the arthroscopy group vs. 26.1% in the MRI group (p = .06). CONCLUSION: Although incidence of meniscal injuries in children tibial eminence fractures is lower than that in adults ACL rupture, pediatric meniscal tears and entrapments need to be systematically searched. MRI does not appear to provide additional information about the entrapment risk if arthroscopy treatment is performed. However, pretreatment MRI provides important informations about concomitant injuries, such as meniscal tears, and should be mandatory if orthopaedic treatment is retained. MRI modalities have yet to be specified to improve the diagnosis of soft tissues entrapments. STUDY DESIGN: Systematic review of the literature REGISTRATION: PROSPERO N° CRD42021258384.

Isolated ballistic femoral condyle fractures: a case series of eighteen patients.

PURPOSE: Ballistic fractures of the femoral condyles are rare injuries with limited literature to help guide treatment. The purpose of this study is to report on the presentation, management, and outcomes for patients with isolated ballistic condylar fractures. METHODS: Eighteen patients between ages 16 and 65 with low-energy ballistic injuries isolated to the femoral condyles (OTA 33B) were included, 15 with CT imaging. Clinical records and imaging were reviewed, as well as treatment strategy. Fractures were classified by AO/OTA classification. Outcome and follow-up data were gathered at outpatient appointments and telephone calls. RESULTS: Of the 18 patients, 78% were treated operatively (61% with open reduction and internal fixation, 17% with removal of foreign body alone). There were two instances of traumatic vascular injury and no neurologic injuries. Furthermore, there were no identified infections. Only 58% of the patients had follow-up for more than 6 weeks with average KOOS Jr. Score of 50, and average VAS pain score of 5.2. CONCLUSIONS: Ballistic femoral condyle fractures are rare Orthopaedic injuries seen in relatively high frequency at our institution. Most (78%) were treated operatively and with few complications. These fractures are not easily classified according to common classification schemes and may benefit from more rigorous study to guide treatment and anticipate outcomes.

High reoperation and mortality rate after distal femoral replacement for periprosthetic knee fracture in the elderly.

PURPOSE: To analyze the outcomes of elderly patients with periprosthetic fractures around the knee operated on with a distal femur replacement (DFR). METHODS: We performed a retrospective case series study of eleven elderly patients who underwent DFR due to a periprosthetic fracture. Mean follow-up was 30.1 months (SD 28.1). Demographic, clinical and radiological data were reviewed. A descriptive analysis and a study of survival were conducted. Then, a comparative analysis between the patients who needed reoperation and did not need reoperation, and the patients who died and the patients who were alive during the follow-up was performed. RESULTS: Mean age was 77.1 years (SD 13.9). Reoperation rate was 36%, being infection the most common complication (27%). The risk of reoperation increased with a longer time between fracture and surgery. The 36.4% of patients died during the follow-up. Older age, need of blood transfusion and need of early reoperation were related to a higher risk of mortality. CONCLUSION: DFR could be a valuable option for knee periprosthetic fractures in elderly patients. However, surgeons should be aware of the high reoperation and mortality rate.

[Clinical study of electroacupuncture therapy on postoperative rehabilitation of patients with knee fractures].

OBJECTIVE: To investigate the effect of electroacupuncture therapy on postoperative rehabilitation training of patients with knee fractures. METHODS: Patients with knee fractures from July 2020 to July 2021 were randomly assigned to either the experimental group or a control group according to the double-blind principle. Both groups were given surgical treatment and postoperative conventional rehabilitation training. There were 40 cases in the control group, including 27 males and 13 females;the age ranged from 20 to 66 years old with an average of (36.46±6.29) years old, continuous passive motion (CPM) training was performed after operation. There were 40 patients in the experimental group, including 24 males and 16 females. The age ranged from 21 to 68 years old with an average of (37.62±7.08) years old, on the basis of the control group, electroacupuncture was given. After 4 weeks of intervention, the excellent rate of knee function score, visual analogue scale (VAS) before and after intervention, serum pain mediators, prostaglandin E (PGE), substance P (SP), bradykinin (BK), joint range of motion and quality of life were compared between the two groups. RESULTS: After 4 weeks of intervention, the Rasmussen score for knee function in the experimental group (24.15±1.36) scores was higher than that in the control group (21.25±2.20) scores (P<0.001). The VAS in the experimental group (2.04±0.51) scores was lower than that in the control group (2.78±0.60) after 4 weeks of intervention (P<0.05). Serum PGE (2.25±0.37) mg·L-1, SP (4.43±1.05) ng·ml-1, BK (2.67±0.68) ng·ml-1 in the experimental group were lower than those in the control group (3.91±0.44) mg·L-1, (6.12±1.37) ng·ml-1, (4.55±1.03) ng·ml-1 after 4 weeks of intervention(P<0.05);in the experimental group, the active knee flexion angle of the knee joint was (108.63±9.76)°, the active knee extension angle (-2.46±0.70)°, passive knee flexion angle (116.83±6.57)°, passive knee extension angle (1.44±0.38)° were better than control group (100.24±8.15)°, (-3.51±0.86)°, (111.04±8.22)°, (0.78±0.24)° (P<0.05);the experimental group's psychological score (73.12±5.08), physiological score (72.26±5.89), social function score (72.57±4.23), overall health score (75.12±5.16) were higher than that of the control group (68.49±4.13), (68.13±5.27), (69.04±3.42), and(70.88±3.97) respectvely(P<0.05). CONCLUSION: Electroacupuncture combined with CPM training after knee fracture surgery can significantly improve knee function and range of motion, reduce pain levels, and also improve quality of life and reduce the incidence of adverse events.

Clinical and Functional Outcomes of Suture Versus Headless Screw Fixation for Tibial Eminence Fractures in Children.

BACKGROUND: Suture and screw fixations are widely used to treat tibial eminence fractures (TEFs). Although a few biomechanical and clinical studies have compared suture fixation (SF) and screw fixation in the treatment of TEFs in children, no comparative clinical studies are available regarding headless screw fixation (HSF). PURPOSE: To evaluate the clinical and functional outcomes of children with TEF who underwent SF and HSF. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: The study included 24 patients treated with either SF (11 patients) or HSF (13 patients) within 1 month of TEF (type 2 or 3) without associated ligamentous and bone injury between 2015 and 2020. All patients were evaluated at a minimum 2-year follow-up in terms of Lysholm score, Tegner activity level, International Knee Documentation Committee subjective score, and isometric strength test. Knee stability was compared based on the Lachman test, pivot-shift test, and KT-1000 arthrometer side-to-side difference. RESULTS: No significant differences were found between the 2 groups in terms of Lysholm score, Tegner activity level, and International Knee Documentation Committee subjective score at follow-up. All patients were able to resume their daily activities within 6 months after the injury. However, flexion deficits (6°-10°) were found in 2 patients in the SF group and 1 patient in the HSF group, and extension deficits (3°-5°) were found in 3 patients in the SF group and 1 patient in the HSF group, without significant intergroup difference. Stability based on the Lachman test, pivot-shift test, and KT-1000 arthrometer side-to-side difference was also similar between the 2 groups at follow-up. No statistically significant difference was found between the 2 groups in isometric tests performed. CONCLUSION: The present study is the first to compare the clinical and functional results of SF and HSF techniques. The HSF technique demonstrated comparable clinical and functional outcomes, suggesting its potential as an alternative to the SF technique.

MRI-Based Classification for Tibial Spine Fracture: Detection Efficacy, Classification Accuracy, and Reliability.

RATIONALE AND OBJECTIVES: Recently, a new MRI-based classification for evaluating tibial spine fractures (TSFs) was developed to aid in treating these injuries. Our objective was to assess the detection efficacy, classification accuracy, and reliability of this classification in detecting and grading TSFs, as well as its impact on treatment strategy, compared to the Meyers and McKeever (MM) classification. MATERIALS AND METHODS: A retrospective study included 68 patients with arthroscopically confirmed TSFs. All patients had plain radiography and conventional MRI of the affected knee before arthroscopy. Three experienced radiologists independently reviewed all plain radiographs and MRI data and graded each patient according to MM and MRI-based classifications. The detection efficacy, classification accuracy, and inter-rater agreement of both classifications were evaluated and compared, using arthroscopic findings as the gold standard. RESULTS: The final analysis included 68 affected knees. Compared to the MM classification, the MRI-based classification produced 22.0% upgrade of TSFs and 11.8% downgrade of TSFs. According to the reviewers, the fracture classification accuracy of the MRI-based classification (91.2-95.6%) was significantly higher than that of the MM classification (73.5-76.5%, p = 0.002-0.01). The fracture detection rate of MRI-based classification (94.1-98.5%) was non-significantly higher than that of the MM classification (83.8-89.7%, p = 0.07-0.4). The soft tissue injury detection accuracy for MRI-based classification was 91.2-94.1%. The inter-rater reliability for grading TSFs was substantial for both the MM classification (κ = 0.69) and MRI-based classification (κ = 0.79). CONCLUSION: MRI-based classification demonstrates greater accuracy and reliability compared to MM classification for detecting and grading TSFs and associated soft tissue injuries.

Tibial Spine Fractures in the Child and Adolescent Athlete: A Systematic Review and Meta-analysis.

BACKGROUND: Tibial spine fractures (TSFs) are uncommon injuries that may result in substantial morbidity in children. A variety of open and arthroscopic techniques are used to treat these fractures, but no single standardized operative method has been identified. PURPOSE: To systematically review the literature on pediatric TSFs to determine the current treatment approaches, outcomes, and complications. STUDY DESIGN: Meta-analysis; Level of evidence, 4. METHODS: A systematic review of the literature was performed in accordance with the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) guidelines using PubMed, Embase, and Cochrane databases. Studies evaluating treatment and outcomes of patients <18 years old were included. Patient demographic characteristics, fracture characteristics, treatments, and outcomes were abstracted. Descriptive statistics were used to summarize categorical and quantitative variables, and a meta-analytic technique was used to compare observational studies with sufficient data. RESULTS: A total of 47 studies were included, totaling 1922 TSFs in patients (66.4% male) with a mean age of 12 years (range, 3-18 years). The operative approach was open reduction and internal fixation in 291 cases and arthroscopic reduction and internal fixation in 1236 cases; screw fixation was used in 411 cases and suture fixation, in 586 cases. A total of 13 nonunions were reported, occurring most frequently in Meyers and McKeever type III fractures (n = 6) and in fractures that were treated nonoperatively (n = 10). Arthrofibrosis rates were reported in 33 studies (n = 1700), and arthrofibrosis was present in 190 patients (11.2%). Range of motion loss occurred significantly more frequently in patients with type III and IV fractures (P < .001), and secondary anterior cruciate ligament (ACL) injury occurred most frequently in patients with type I and II fractures (P = .008). No statistically significant differences were found with regard to rates of nonunion, arthrofibrosis, range of motion loss, laxity, or secondary ACL injury between fixation methods (screw vs suture). CONCLUSION: Despite variation in TSF treatment, good overall outcomes have been reported with low complication rates in both open and arthroscopic treatment and with both screw and suture fixation. Arthrofibrosis remains a concern after surgical treatment for TSF, but no significant difference in incidence was found between the analysis groups. Larger studies are necessary to compare outcomes and form a consensus on how to treat and manage patients with TSFs.

Arthroscopic suture fixation of tibial spine fractures.

A tibial spine fracture refers to an intraarticular fracture of the osseous insertion of the anterior cruciate ligament at the proximal tibia, commonly seen in pediatric and adolescent patients. This fracture is classified based on the degree of displacement and the presence or absence of an intact posterior hinge point. For significantly displaced fractures, surgical reduction and fixation are often recommended. Both open and arthroscopic approaches have been described. This technical note describes our technique for arthroscopic-assisted reduction and fixation of tibial spine fractures using trans-osseous tunnels and suture fixation over a bone bridge. This technique restores native anatomy, provides fracture compression, and has favorable biomechanical properties, allowing for early range of motion.

Bilateral trochlear subchondral insufficieny fracture of the knee in a professional cyclist.

This case report presents a rare case of subsequent ipsilateral and contralateral subchondral insufficiency fracture of the knee (SIFK) in the trochlea of the femur within months, manifested in a professional cyclist. SIFKs in the trochlea have not yet been reported in the literature; however, their appearance in a professional cyclist might be explained by the amount of repetitive pressure on the patellofemoral joint when cycling. In both instances, atraumatic anterior knee pain occurred, resolving after conservative treatment for 6-9 weeks. The patient reached their previous activity level. The authors believe SIFK in the younger population may be more common than currently perceived due to its self-limiting behaviour and a lack of performing immediate MRIs in this younger group whenever an overload injury is suspected.

Dual-energy CT Virtual Non-Calcium Image is Beneficial for the Detection of Non-displaced Knee Fractures.

BACKGROUND: Early and accurate diagnosis is vital for avoiding the development of nondisplaced fractures to displaced fractures. Dual-energy CT (Computed Tomography) can detect bone marrow edema (BME), which may help to detect non-displaced fractures. AIM: To evaluate the value of DECT (Dual-Energy Computed Tomography) VNCa (Virtual noncalcium) images for improving diagnostic performance and confidence in acute non-displaced knee fractures. METHODS: 125 patients with clinical suspicion of knee fractures underwent both DECT and MR. Conventional linear-blended CT and VNCa images were obtained from DECT. First, five readers with varying levels of experience evaluated the presence of fractures on conventional linear-blended CT and graded their diagnostic confidence on a scale of 1 to 10. Then BME with VNCa images was evaluated and compared with MR. Finally, the VNCa images combined with conventional linear-blended CT images were used to reassess the presence of fractures and diagnostic confidence. Diagnostic performance and matched pair analyses were performed. RESULTS: 20 non-displaced knee fractures were detected. The consistency test of VNCa images and MR by five radiologists showed Kappa values are 0.76, 0.79, 0.81,0.85,and 0.90,respectively. The diagnostic performance of all readers was improved when using VNCa images combined with conventional linear-blended CT compared with that with conventional linear-blended CT alone. Diagnostic confidence was improved with combined conventional linear-blended CT and VNCa images (median score:8,8,9,9, and 10, respectively) compared with conventional linear-blended CT alone (median score:7,7,8,9, and 9). CONCLUSION: DECT VNCa images could improve the radiologists' diagnostic performance and confidence with varying levels of experience in the detection of non-displaced knee fractures.

Arthroscopically-assisted retrieval of a fractured polyethylene Oxford knee meniscal bearing: a case report.

Fracture of a polyethylene insert in a knee prosthesis is an uncommon but severe complication resulting in an unstable and malfunctioning knee that requires revision surgery. The aim of this paper was to present our experience with a minimally-invasive option for retrieving a posteriorly-migrated fragment of a mobile tibial bearing, which is a rare complication. We describe the management of a case of breakage of an Oxford knee medial bearing. Half of the mobile bearing was retrieved from the suprapatellar recess, while the other half had migrated posteriorly to the femoral condyle and was retrieved through an arthroscopically-assisted approach with the help of a posteromedial port. At the follow-up, no further complaints were reported by the patient, and activities of daily living were possible without pain or limitations. This report of a breakage of the mobile bearing following Oxford knee medial prosthesis placement demonstrates that in the event of breakage of the bearing, an arthroscopically-assisted approach is safe in the removal of the bearing and allows its replacement.

Screws or Sutures? A Pediatric Cadaveric Study of Tibial Spine Fracture Repairs.

BACKGROUND: Tibial spine fractures are common in the pediatric population because of the biomechanical properties of children's subchondral epiphyseal bone. Most studies in porcine or adult human bone suggest that suture fixation performs better than screw fixation, but these tissues may be poor surrogates for pediatric bone. No previous study has evaluated fixation methods in human pediatric knees. PURPOSE: To quantify the biomechanical properties of 2-screw and 2-suture repair of tibial spine fracture in human pediatric knees. STUDY DESIGN: Controlled laboratory study. METHODS: Cadaveric specimens were randomly assigned to either 2-screw or 2-suture fixation. A standardized Meyers-Mckeever type 3 tibial spine fracture was induced. Screw-fixation fractures were reduced with two 4.0-mm cannulated screws and washers. Suture-fixation fractures were reduced by passing 2 No. 2 FiberWire sutures through the fracture fragment and the base of the anterior cruciate ligament. Sutures were secured through bony tunnels over a 1-cm tibial cortical bridge. Each specimen was mounted at 30° of flexion. A cyclic loading protocol was applied to each specimen, followed by a load-to-failure test. Outcome measures were ultimate failure load, stiffness, and fixation elongation. RESULTS: Twelve matched pediatric cadaveric knees were tested. Repair groups had identical mean (8.3 years) and median (8.5 years) ages and an identical number of samples of each laterality. Ultimate failure load did not significantly differ between screw (mean ± SD, 143.52 ± 41.9 7 N) and suture (135.35 ± 47.94 N) fixations (P = .760). Screws demonstrated increased stiffness and decreased elongation, although neither result was statistically significant at the .05 level (21.79 vs 13.83 N/mm and 5.02 vs 8.46 mm; P = .076 and P = .069, respectively). CONCLUSION: Screw fixation and suture fixation of tibial spine fractures in human pediatric tissue were biomechanically comparable. CLINICAL RELEVANCE: Suture fixations are not biomechanically superior to screw fixations in pediatric bone. Pediatric bone fails at lower loads, and in different modes, compared with adult cadaveric bone and porcine bone. Further investigation into optimal repair is warranted, including techniques that may reduce suture pullout and "cheese-wiring" through softer pediatric bone. This study provides new biomechanical data regarding the properties of different fixation types in pediatric tibial spine fractures to inform clinical management of these injuries.

Arthroscopic-assisted Treatment of a Posterolateral Tibial Plateau Fracture with an Accompanying Tibial Eminence Fracture. Case Report.

Posterolateral tibial plateau fractures pose a challenge even to the most experienced orthopedic trauma specialists. Arthroscopic fracture management techniques have been emerging as an increasingly popular alternative in the treatment of selected tibial plateau fractures. This technique enables precise visualization of the articular surface of the tibia and its anatomical reduction with lateral meniscus repair, which further enables the restoration of biomechanical function of the meniscus and prevents early degeneration. In addition, this method minimizes soft tissue injury, shortens the duration of hospital stay and postoperative care, and enables treatment of accompanying intra-articular injuries. In our article, we present a case of posterolateral tibial plateau fracture with articular displacement and depression, and loss of support for the posterior margin of the lateral meniscus with an accompanying tibial eminence fracture. The fracture was treated with arthroscopic assistance. Anatomical reduction of the tibial eminence and the fragment of the posterolateral tibial plateau, as well as lateral meniscus repair was achieved intraoperatively. Postoperative radiographic assessment showed anatomical restoration of the articular surface. A full range of motion and pain-free knee stability were achieved following rehabilitation.