Injured Knee Research Articles

Outcomes following the operative treatment of intra-articular fracture combined with medial patellofemoral ligament reconstruction after patellar dislocation

PurposeWe examine the outcomes following operative treatment of intra-articular fracture combined with medial patellofemoral ligament (MPFL) reconstruction after patella dislocation.MethodsPatients were retrospectively identified from medical records using diagnostic and surgical procedure codes. Radiological anatomical parameters and bony abnormalities of injured knees were assessed from magnetic resonance images (MRI). Inclusion criteria were traumatic patellar dislocation with chondral or osteochondral fracture and MPFL rupture, operative treatment of a chondral or osteochondral fracture combined with MPFL reconstruction, and minimum follow-up of 2 years. Outcomes were measured using the Kujala score, Tegner activity scale, and the Knee injury and Osteoarthritis Outcome Score Quality-of-Life subscale (KOOS-QLS).ResultsDuring 2012 and 2015, 322 patients were treated because of patellar dislocation. Thirty-three patients had chondral or osteochondral fracture. Eleven patients (five males and six females) with a mean [standard deviation (SD)] age of 17.0 (6.5) years at the time of surgery met the inclusion criteria and were included. Five of the 11 patients had a subchondral and six an osteochondral fracture. Eight patients had a fracture in the patella and three in the femur. All patients had bony abnormalities in the knee. Nine out of 11 patients scored over 90/100 points on the Kujala scale and had good results on the Tegner scale [before surgery 5.0 (2.7) points versus after surgery 5.3 (1.6) points] and the KOOS-QLS [4.1 (4.2) points] outcome measures.ConclusionThe removal or fixation of the fracture fragment combined with MPFL reconstruction is a feasible option in the treatment of symptomatic osteochondral or subchondral fragment in traumatic patellar dislocation. The short-term outcomes are encouraging.Level of evidence: Level IV, retrospective case series.

Dynamic Ultrasound Assessment of the Anterior Tibial Translation for Anterior Cruciate Ligament Tears Diagnostic.

The aim of our study was to investigate the accuracy of dynamic ultrasound assessment of the anterior tibial translation, in diagnosing anterior cruciate ligament tears, and to assess its test–retest reliability. Twenty-three patients (32 ± 8.42 years; 69.56% males) with a history of knee trauma and knee instability participated in the study. Knee ultrasound was performed by an experienced orthopedic surgeon. The anterior tibial translation was measured in both knees and differences between the injured and uninjured knee were calculated. Side-to-side differences > 1 mm were considered a positive diagnosis of an ACL tear. The anterior tibial translation values were 3.34 ± 1.48 mm in injured knees and 0.86 ± 0.78 mm in uninjured knees. Side-to-side differences > 1 mm were found in 22 cases (95.65%). The diagnosis accuracy was 91.30% (95%CI: 71.96–98.92%) and sensitivity 95.45% (95%CI: 77.15–99.88%). The intraclass correlation coefficient showed an excellent test–retest reliability (ICC3,1 = 0.97 for the side-to-side difference in anterior tibial translation). The study highlights the accuracy and reliability of the dynamic ultrasound assessment of the anterior tibial translation in the diagnosis of unilateral anterior cruciate ligament tears. Ultrasound assessment is an accessible imaging tool that can provide valuable information and should be used together with physical examination in suspected cases of ACL injuries.

Quantitative evaluation of the tibiofemoral joint cartilage by T2 mapping in patients with acute anterior cruciate ligament injury vs contralateral knees: results from the subacute phase using data from the NACOX study cohort

Immediate cartilage structural alterations in the acute phase after an anterior cruciate ligament (ACL) rupture may be a precursor to posttraumatic osteoarthritis (PTOA) development. Our aim was to describe changes in cartilage matrix in the subacute phase of the acutely ACL-injured knee compared to the contralateral uninjured knee. Participants (n=118) aged 15-40 years with an acute ACL injury were consecutively included in subacute phase after acute ACL-injury and underwent MRI (mean 29 days post trauma) of both knees. Mean T2 relaxation times, T2 spatial coefficient of variation and cartilage thickness were determined for different regions of the tibiofemoral cartilage. Differences between the acutely ACL-injured and uninjured knee were evaluated using Wilcoxon signed-rank test. T2 relaxation time in injured knees was increased in multiple cartilage regions from both medial and lateral compartment compared to contralateral knees, mostly in medial trochlea and posterior tibia (P-value<0.001). In the same sites of injured knees, we observed significantly thinner cartilage. Moreover, injured knees presented shorter T2 relaxation time in superficial cartilage on lateral central femur and trochlea (P-value<0.001), and decreased T2 spatial coefficient of variation in lateral trochlea and load bearing regions of medial-central femoral condyle and central tibia in both compartments. Small but statistically significant differences were observed in the subacute phase between ACL-injured and uninjured knee in cartilage T2 relaxation time and cartilage thickness. Future longitudinal observations of the same cohort will allow for better understanding of early development of PTOA. NCT02931084.

Examining the Bone Bruise Patterns in Multiligament Knee Injuries With Peroneal Nerve Injury

Background: Tibiofemoral bone bruise patterns seen on magnetic resonance imaging (MRI) are associated with ligamentous injuries in the acutely injured knee. Bone bruise patterns in multiligament knee injuries (MLKIs) and particularly their association with common peroneal nerve (CPN) injuries are not well described. Purpose: To analyze the tibiofemoral bone bruise patterns in MLKIs with and without peroneal nerve injury. Study Design: Case series; Level of evidence, 4. Methods: We retrospectively identified 123 patients treated for an acute MLKI at a level 1 trauma center between January 2001 and March 2021. Patients were grouped into injury subtypes using the Schenck classification. Within this cohort, patients with clinically documented complete (motor and sensory loss) and/or partial CPN palsies on physical examination were identified. Imaging criteria required an MRI scan on a 1.5 or 3 Tesla scanner within 30 days of the initial MLKI. Images were retrospectively interpreted for bone bruising patterns by 2 board-certified musculoskeletal radiologists. The location of the bone bruises was mapped on fat-suppressed T2-weighted coronal and sagittal images. Bruise patterns were compared among patients with and without CPN injury. Results: Of the 108 patients with a MLKI who met the a priori inclusion criteria, 26 (24.1%) were found to have a CPN injury (N = 20 complete; N = 6 partial) on physical examination. For CPN-injured patients, the most common mechanism of injury was high-energy trauma (N = 19 [73%]). The presence of a grade 3 posterolateral corner (PLC) injury (N = 25; odds ratio [OR], 23.81 [95% CI, 3.08-184.1]; P = .0024), anteromedial femoral condyle bone bruising (N = 24; OR, 21.9 [95% CI, 3.40-202.9]; P < .001), or a documented knee dislocation (N = 16; OR, 3.45 [95% CI, 1.38-8.62]; P = .007) was significantly associated with the presence of a CPN injury. Of the 26 patients with CPN injury, 24 (92.3%) had at least 1 anteromedial femoral condyle bone bruise. All 20 (100%) patients with complete CPN injury also had at least 1 anteromedial femoral condyle bone bruise on MRI. In our MLKI cohort, the presence of anteromedial femoral condyle bone bruising had a sensitivity of 92.3% and a specificity of 64.6% for the presence of CPN injury on physical examination. Conclusion: In our MLKI cohort, the presence of a grade 3 PLC injury had the greatest association with CPN injury. Additionally, anteromedial femoral condyle bone bruising on MRI was a highly sensitive finding that was significantly correlated with CPN injury on physical examination. The high prevalence of grade 3 PLC injuries and anteromedial tibiofemoral bone bruising suggests that these MLKIs with CPN injuries most commonly occurred from a hyperextension-varus mechanism caused by a high-energy blow to the anteromedial knee.

Elevated Patellofemoral and Tibiofemoral T1ρ Relaxation Times Following a First Time Patellar Dislocation.

ObjectiveThe study was performed to evaluate cartilage within the knee following a first-time patellar dislocation, using elevated MRI-based T1ρ relaxation times as an indicator of low proteoglycan concentration. The hypothesis is that MRI-based T1ρ relaxation times for patellofemoral and tibiofemoral cartilage are significantly longer for knees being treated for patellar dislocation than for healthy control knees.DesignTwenty-one subjects being treated for a first-time, unilateral dislocation of the patella and 16 healthy controls participated in MRI-based T1ρ relaxation time mapping. Mean relaxation times were quantified for patellofemoral and tibiofemoral regions for injured knees, the contralateral knees, and healthy controls. T1ρ values for each region were compared between the 3 groups with generalized estimating equations. Linear regressions were also performed to correlate T1ρ relaxation times with time from injury.ResultsThe knees with a disloction had longer T1ρ relaxation times than the contralateral knees and control group at the medial patella and longer relaxation times than the control group at the lateral tibia (P < 0.05). T1ρ relaxation times at the medial patella also decreased with time from injury (r2 = 0.21, P = 0.037).ConclusionsCompositional changes to cartilage on the medial patella are related to traumatic impact during a dislocation. Potential exists for cartilage properties at the medial patella to improve with time. Cartilage degradation at the lateral tibia is not directly related to traumatic impact. The current baseline data are a starting point to characterize the pathway from a first-time dislocation to progressive cartilage degradation and osteoarthritis.

302 Abaloparatide as a novel therapy for posttraumatic osteoarthritis

OBJECTIVES/GOALS: Osteoarthritis (OA) is a cartilage destroying disease. We are investigating abaloparatide (ABL) activation of parathyroid hormone receptor type 1 (PTH1R), which is expressed by articular chondrocytes in OA. We propose ABL treatment is chondroprotective in murine PTOA via stimulation of matrix production and inhibition of chondrocyte maturation. METHODS/STUDY POPULATION: 16-week-old C57BL/6 male mice received destabilization of the medial meniscus (DMM) surgery to induce knee PTOA. Beginning 2 weeks post-DMM, 40 μg/kg of ABL (or saline) was administered daily via subcutaneous injection and tissues were harvested after 6 weeks of daily injections and 8 weeks after DMM surgery. Harvested joint tissues were used for histological and molecular assessment of OA using three 5 μm thick sagittal sections from each joint, 50 μm apart, cut from the medial compartment of injured knees. Safranin O/Fast Green tissue staining and immunohistochemistry-based detection of type 10 collagen (Col10) and lubricin (Prg4) was performed using standard methods. Histomorphometric quantification of tibial cartilage area and larger hypertrophic-like cells was performed using the Osteomeasure system. RESULTS/ANTICIPATED RESULTS: Safranin O/Fast Green stained sections showed a decreased cartilage loss in DMM joints from ABL-treated versus saline-treated mice. Histomorphometric analysis of total tibial cartilage area revealed preservation of cartilage tissue on the tibial surface. Immunohistochemical analyses showed that upregulation of Col10 in DMM joints was mitigated in the cartilage of ABL-treated mice, and chondrocyte expression of Prg4 was increased in uncalcified cartilage areas in ABL-treated group. The Prg4 finding suggests a matrix anabolic effect that may counter OA cartilage loss. Quantification of chondrocytes in uncalcified and calcified tibial cartilage areas revealed a reduction in the number of larger hypertrophic-like cells in ABL treated mice, suggesting deceleration of hypertrophic differentiation. DISCUSSION/SIGNIFICANCE: Cartilage preservation/regeneration therapies would fill a critical unmet need. We demonstrate that an osteoporosis drug targeting PTH1R decelerates PTOA in mice. ABL treatment was associated with preservation of cartilage, decreased Col10, increased Prg4, and decreased number of large hypertrophic-like chondrocytes in the tibial cartilage.

Current Standards of Early Rehabilitation after Anterior Cruciate Ligament Reconstruction in German Speaking Countries-Differentiation Based on Tendon Graft and Concomitant Injuries.

Background: Although anterior cruciate ligament reconstruction (ACLR) is a well-established procedure and is standardly performed by orthopedic surgeons all over the world, there does not seem to be a standard protocol for early rehabilitation. The purpose of this study was to give answers to the following questions: (i) Does (a) the use of a specific tendon graft, and (b) potentially additional therapy of concomitant pathologies influence surgeons’ choice of a distinct postoperative rehabilitation protocol after ACLR? (ii) To what extent do these rehabilitation recommendations differ? Methods: Retrospective analysis of currently used early rehabilitation protocols after ACLR in German-speaking countries (GER, AUT and SUI) was conducted. Rehabilitation criteria included weight bearing, range of motion (ROM), the utilization of braces, continuous passive/active motion therapy (CPM/CAM), rehabilitation training and sport-specific training. Tendon grafts were differentiated as hamstring (HAM) and bone–patellar tendon–bone grafts (BTB). Concomitant pathologies included meniscus injuries (+M) and unhappy triad injuries (+UTI). Results: Most of the surveyed protocols were differentiated according to the used tendon graft or additional therapy of concomitant injuries (ACLR-differentiated, n = 147 vs. ACLR without graft differentiation, n = 58). When comparing ACLR-HAM and ACLR-BTB, significant differences were found regarding weight bearing (p = 0.01), ROM (p = 0.05) and the utilization of braces (p = 0.03). Regarding ACLR+M, an overall significant decelerated rehabilitation could be detected. After ACLR+UTI-therapy, a significant delayed start to full weight bearing (p = 0.002) and ROM (p < 0.001) was found. Conclusions: Most orthopedic surgeons from German-speaking countries differentiate early rehabilitation after ACLR according to the tendon graft used and therapy of concomitant pathologies. No consensus about early rehabilitation after ACLR is available. However, tendencies for an accelerated rehabilitation after ACLR-BTB and a more restrained rehabilitation of multiple injured knees were detected.

Does the Extension Torque Control Differ between Injured and Uninjured Knees of ACL-Deficient Individuals?

Background: Knee extension torque control decreases after anterior cruciate ligament (ACL) rupture. There is a controversy in neuromuscular control changes on the uninvolved side. We intended to evaluate the steadiness and accuracy of quadriceps muscle control in the healthy and deficient sides of people with acute ACL rupture. Methods: In this cross-sectional study, thirteen men with ACL rupture (age: 27.8±7.0, body mass index (BMI): 24.7±2.25: 24.7, days from injury: 48.1±21.3) participated in the study. We measured quadriceps force control, which is quantitatively assessed by the standard deviation (SD) of joint torque for a predefined submaximal target. The accuracy of muscular control or performance of quadriceps is commonly quantified by the root mean square of error (RMSE) was also measured. A two-way analysis of variance was conducted to assess SD and RMSE of two levels of quadriceps contraction (30% of muscle voluntary contraction (MVC), 50% of MVC) across both healthy and deficient knees. Results: There was a significant main effect for SD and RMSE of MVC percentage (p<0.001). SD of quadriceps torque in 50% of MVC (1.44 ± 0.13) was higher than 30% of MVC (0.88 ± 0.1). In contrast, there was no significant main effect for SD and RMSE of knee condition. Conclusion: After unilateral ACL rupture, the neuromuscular system becomes defected and quadriceps muscle control is then reduced in the healthy side. Therefore, the healthy side is also vulnerable to ligamentous damage. Besides, with the increasing intensity of physical activities, neuromuscular control decreases and the risk of re-injury rises.

Osteoarthritis Progression after ACL Reconstruction Was Significantly Higher Than That of the Healthy Contralateral Knees: Long-Term Follow Up Study of Mean 16.4 Years.

Background: This study aimed to assess long-term progression of osteoarthritis (OA) after isolated anterior cruciate ligament (ACL) reconstruction in athletes compared to the healthy contralateral side. Methods: The study included 15 patients and 30 knees with a mean age of 40 years (range, 35–46) years, none of whom had had revision surgery or an injury to the contralateral side. The mean follow-up period was 16.4 years (range, 13–22). Clinical and radiographic assessment included the Tegner activity scale (TAS), International Knee Documentation Committee (IKDC) score, Knee injury and Osteoarthritis Outcome Score (KOOS), and Kellgren and Lawrence (KL) grade. The long-term results of the injured knees were compared with the status of the healthy contralateral side and compared with previously published mid-term results of the same cohort of patients. Results: Patients generally remained clinically asymptomatic or mildly symptomatic at final follow-up, which is reflected by a KOOS pain score of 33 points (maximum 36 points) and an IKDC total subjective score of 87% (maximum 100%). There was a significant difference between mid-term and final follow-up in terms of the function score of the IKDC subjective questionnaire (p = 0.031), compartment findings and donor site morbidity of the IKDC functional examination (both p = 0.034), and the total KOOS score (p = 0.047). The KL score indicated significant progression of OA from mid-term to final follow-up in the injured knees (p = 0.004) and healthy contralateral knees (p = 0.014). Mean OA grades of the injured knees were significantly higher compared with the healthy contralateral side (p = 0.006) at final follow-up, and two patients showed moderate to severe signs of OA in the injured knee. Conclusions: Although most patients remained clinically asymptomatic or mildly symptomatic, long-term progression of OA after isolated ACL reconstruction in athletes was significantly higher compared with the healthy contralateral knee.

The time from injury to surgery is an important factor affecting the mechanoreceptors at stump of torn anterior cruciate ligament.

Restoration of proprioceptive function after anterior cruciate ligament (ACL) reconstruction is as important as mechanical stability. For this purpose, remnant of the torn ACL is the only source of nerve endings. Our aim in this study is to investigate the quantity of mechanoreceptors in the remnants ACL stumps in injured knees and to correlate that with the quantity in intact ACL in control cases. 48 patients that underwent ACL reconstruction between January 2016 and December 2018 as study group and 20 knees of 10 fresh frozen cadavers that as control group included in the study. Remaining stumps from study group and native ACL from control group were collected and investigated with S100 immunostaining. The type and number of mechanoreceptors in standardized areas was determined. The correlation of number of mechanoreceptors and time to surgery after ACL rupture were evaluated. The free nerve endings (FNE) and total number of mechanoreceptors were significantly lower in the study group as compared to the control group (p < 0.001 and p = 0.004, respectively). The number of Golgi-Mazzoni corpuscle decreased significantly with time (p = 0.041 CC: -0.438). The time from injury to surgery is an important factor affecting the mechanoreceptors at stump of torn ACL. The surgeon and patient should be aware of the fact that delay in surgery could lead to the loss of mechanoreceptors.

Knee dynamics during take-off and landing in spike jumps performed by volleyball players with patellar tendinopathy.

[Purpose] Patellar tendinopathy is a common sports injury. The risk factors for this injury can be categorized as intrinsic, extrinsic, and dynamic. We examined the dynamic factors in this study. [Participants and Methods] The participants were volleyball players who were assigned to a patient group (n=6) if they had medial patellar tendinopathy in the left knee or to a control group (n=7) otherwise. The participants performed spike jumps, and their ground reaction force and three-dimensional kinematic data were recorded. Knee angle and moment data were extracted at the peak extension moment of take-off and landing. [Results] The two groups showed no differences in knee angles. A tendency for abduction/external rotation moments at take-off and landing on both sides was observed in the control group, while the patient group showed adduction and internal rotation moments at take-off and adduction moment at landing in the left (injured) knee. [Conclusion] The observed knee joint moments in the left (injured) knee of the patient group may have been involved in the pathophysiological mechanism underlying the development of patellar tendinopathy.

CLINICAL OUTCOMES OF TORQUE DEFICIT REDUCTION IN KNEE EXTENSORS AND FLEXORS AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

In this prospective study, we presented the effect of isokinetic training on the clinical outcome of rehabilitation in relation to the reduction of the torque deficit in thigh muscles (DEF) after anterior cruciate ligament (LCA) reconstruction. The prospective study followed 144 subjects, 72 women and 72 men, with a mean age of 28.20 ± 4.52, four months after anterior cruciate ligament reconstruction with a hamstring graft. Subjects were divided into two groups according to the type of rehabilitation treatment they underwent. Subjects of the isokinetic group (72 subjects, 36 males and 36 females), underwent kinesitherapy according to the isokinetic exercise protocol which consisted of a one-day isokinetic training lasting for thirty minutes, five times a week for six weeks. Subjects of the classical group (72 subjects, 36 males and 36 females) underwent kinesitherapy based on standard isotonic exercises to increase muscle strength, i.e. exercises with weights and in the gym. The difference in the outcome of rehabilitation was objectified by a concentric-concentric isokinetic test at an angular velocity of 60 °/s before the start, after three weeks and after six weeks of rehabilitation. The monitoring parameters were: torque deficit of the injured leg knee extensor in relation to the uninjured leg (EXDEF) -% and torque deficit of the knee flexor of the injured leg in relation to the uninjured leg (FLDEF) -%.

Twelve Weeks of a Staged Balance and Strength Training Program Improves Muscle Strength, Proprioception, and Clinical Function in Patients with Isolated Posterior Cruciate Ligament Injuries.

Ligament reconstruction is indicated in patients with an isolated posterior cruciate ligament (PCL) injury who fail conservative treatment. To eliminate the need for PCL reconstruction, an ideal rehabilitation program is important for patients with an isolated PCL injury. The purpose of this study was to investigate the improvement in functional outcome, proprioception, and muscle strength after a Both Sides Up (BOSU) ball was used in a balance combined with strength training program in patients with an isolated PCL injury. Ten patients with isolated PCL injuries were recruited to receive a 12 week training program as a study group. In the control group (post-PCL reconstruction group), ten subjects who had undergone isolated PCL reconstruction for more than 2 years were enrolled without current rehabilitation. The Lysholm score, IKDC score, proprioception (active and passive), and isokinetic muscle strength tests at 60°/s, 120°/s, and 240°/s, were used before and after training on the injured and normal knees in the study group, and in the post-PCL reconstruction group. The results were analyzed with a paired t-test to compare the change between pre-training, post-training, and the normal leg in the study group, and with an independent t-test for comparisons between the study and post-PCL reconstruction groups. Both the Lysholm and IKDC scores were significantly improved (p < 0.01) after training, and no difference was observed compared to the post-PCL reconstruction group. The active and passive proprioception was improved post-training compared to pre-training, with no difference to that in the post-PCL reconstruction group. Isokinetic knee quadriceps muscle strength was significantly greater post-training than pre-training in PCL injured knees at 60°/s, 120°/s, and 240°/s, and in hamstring muscle strength at 60°/s and 120°/s. Muscle strength in the post-training injured knee group showed no significant difference compared to that in the post-training normal leg and the post-PCL reconstruction group. The post-training improvement of muscle strength was higher in the PCL injured leg compared to the normal leg and there was no difference between the dominant and non-dominant injured leg in the study group. After 12 weeks of BOSU balance with strength training in patients with an isolated PCL injury, the functional outcome, proprioception, and isokinetic muscle strength were significantly improved, and comparable to the contralateral normal leg and the post-PCL reconstruction group. We suggest that programs combining BOSU balance and strength training should be introduced in patients with a PCL injury to promote positive clinical results.

The Lateral Femoral Condyle Index Is Not a Risk Factor for Primary Noncontact Anterior Cruciate Ligament Injury

Background: The lateral femoral condyle index (LFCI)—a recently developed measure of the sphericity of the lateral femoral condyle—was reported to be a risk factor for anterior cruciate ligament (ACL) injury. However, issues have been raised regarding how the index was measured and regarding the patient group and the knee in which it was measured. Purpose: To investigate the association between the LFCI and the risk of sustaining a primary, noncontact ACL injury, and to examine whether this association was moderated by the posterior-inferior–directed slope of the lateral tibial plateau. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A secondary analysis was conducted of deidentified magnetic resonance images of the uninjured knees of 86 athletes with ACL injury and the corresponding knees of 86 control athletes, matched for sports team, sex, and age. From those images, we measured the LFCI and the posterior-inferior–directed slope of the middle region articular cartilage surface of the tibial plateau’s lateral compartment. Conditional logistic regressions were performed to determine whether the LFCI was significantly associated with ACL injury risk and whether the lateral tibial compartment middle cartilage slope moderated this association. Data were analyzed for female and male participants separately as well as for both groups combined. Results: The LFCI was not found to be significantly associated with experiencing a primary, noncontact ACL injury for all analyses. The lateral tibial slope measure was not found to moderate the association between the LFCI and ACL injury. A conditional logistic regression analysis using the LFCI data of the injured knees, instead of the uninjured knees, of the participants with ACL injury revealed that the LFCI was significantly associated with ACL injury. Conclusion: In this population of athletically active female and male participants, the LFCI was not found to be a risk factor for noncontact ACL injury, regardless of the geometric features of the lateral tibial slope.

Knee Avulsion Injuries: What can I Get From a CT?

Acute bone and soft-tissue injuries to the knee are commonly seen in emergency departments as well as in the outpatient clinic. Most commonly, these injuries result from a direct blow, a fall, or a twisting injury. Prompt and accurate diagnosis relies heavily on imaging and is mandatory to facilitate adequate management and prevent potential complications [1]. Radiographs are usually the initial imaging modality in the evaluation of the acutely injured knee but have a low yield. Computed Tomography (CT) may be performed as the next imaging study for the evaluation of suspected radiographically occult fractures. In patients with radiographic diagnosis of knee fracture, CT is frequently performed for further classification and characterization of the fracture severity and for prediction or diagnosis of associated meniscal and ligamentous injuries [12]. The knee has numerous tendinous, ligamentous, and meniscal attachments, which make it particularly vulnerable to avulsion injuries after trauma. These include avulsions of the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL), Segond (small bony avulsion of the anterolateral ligament at the lateral tibial rim that indicates a ACL tear) and reverse Segond (small medial tibial avulsion fracture that indicates a PCL tear) fractures, fibular head avulsion fracture, arcuate complex avulsion, fracture avulsions of the medial collateral ligament, iliotibial band avulsion, avulsions of the semimembranosus, and quadriceps tendons, and patellar sleeve fractures. In the setting of acute twisting trauma to the knee, CT scan has high sensitivity and specificity in detecting bony avulsion fractures and a high negative predictive value for excluding ligamentous injuries (e.g.: ACL avulsion fracture) [3] (Figure 1). Radiologists should recognize the pattern of these injuries and their underlying mechanism to understand the substantial damage that it frequently represents. This presentation will outline the imaging appearances of common knee avulsion fractures. Specific examples will be used to highlight clinical relevance and learning points.

The Effect of Posterior Tibial Slope on the Risk of Revision Surgery After Anterior Cruciate Ligament Reconstruction

Background: A significant proportion of patients undergoing anterior cruciate ligament (ACL) reconstruction (ACLR) later experience graft failure. Some studies suggest an association between a steep posterior tibial slope (PTS) and graft failure. Purpose: To examine the PTS in a large cohort of patients about to undergo ACLR and to determine whether a steep PTS is associated with later revision surgery. Study Design: Case-control study; Level of evidence, 3. Methods: A retrospective review of a cohort undergoing isolated ACLR between 2002 and 2012 (with 8-19 years of follow-up) was conducted. Preoperative sagittal radiographs of knees in full extension were used for measurements of the PTS. There were 2 independent examiners who performed repeated measurements to assess the reliability of the method. Statistical analyses were performed to compare the PTS in the groups with and without later revision surgery. Results: A total of 728 patients, with a mean age of 28 years at the time of surgery, were included. Overall, 10% (n = 76) underwent revision surgery during the observation period. The group of injured knees had a significantly steeper PTS compared with the group of uninjured knees (9.5° vs 8.7°, respectively; P < .05). The mean PTS in the no revision group was 9.5° compared with 9.3° in the revision group (not significant). Dichotomized testing of revision rates related to PTS cutoff values of ≥10°, ≥12°, ≥14°, ≥16°, and ≥18° showed no association of PTS steepness (not significant) to graft failure. Patients with revision were younger than the ones without (mean age, 24 ± 8 vs 29 ± 10 years, respectively) and had a shorter time from injury to ACLR (mean, 14 ± 27 vs 24 ± 44 months, respectively) as well as a smaller graft size (8.2 vs 8.4 mm, respectively; P = .040). Conclusion: The current study did not find any association between a steep PTS measured on lateral knee radiographs and revision ACL surgery. However, a steeper PTS was seen in the group of injured knees compared with the group of uninjured (contralateral) knees. Independent of the PTS, younger patients, those with a shorter time from injury to surgery, and those with a smaller graft size were found to undergo revision surgery more often.

Immune cell profiles in synovial fluid after anterior cruciate ligament and meniscus injuries

BackgroundAnterior cruciate ligament (ACL) and meniscus tears are common knee injuries. Despite the high rate of post-traumatic osteoarthritis (PTOA) following these injuries, the contributing factors remain unclear. In this study, we characterized the immune cell profiles of normal and injured joints at the time of ACL and meniscal surgeries.MethodsTwenty-nine patients (14 meniscus-injured and 15 ACL-injured) undergoing ACL and/or meniscus surgery but with a normal contralateral knee were recruited. During surgery, synovial fluid was aspirated from both normal and injured knees. Synovial fluid cells were pelleted, washed, and stained with an antibody cocktail consisting of fluorescent antibodies for cell surface proteins. Analysis of immune cells in the synovial fluid was performed by polychromatic flow cytometry. A broad spectrum immune cell panel was used in the first 10 subjects. Based on these results, a T cell-specific panel was used in the subsequent 19 subjects.ResultsUsing the broad spectrum immune cell panel, we detected significantly more total viable cells and CD3 T cells in the injured compared to the paired normal knees. In addition, there were significantly more injured knees with T cells above a 500-cell threshold. Within the injured knees, CD4 and CD8 T cells were able to be differentiated into subsets. The frequency of total CD4 T cells was significantly different among injury types, but no statistical differences were detected among CD4 and CD8 T cell subsets by injury type.ConclusionsOur findings provide foundational data showing that ACL and meniscus injuries induce an immune cell-rich microenvironment that consists primarily of T cells with multiple T helper phenotypes. Future studies investigating the relationship between immune cells and joint degeneration may provide an enhanced understanding of the pathophysiology of PTOA following joint injury.

Fraturas da Eminência da Tíbia na Infância – Descrição de Abordagem Artroscópica e Resultados Funcionais

Pediatric fractures of the tibial eminence are relatively rare, equivalent to the anterior cruciate ligament rupture in the adult. Severely displaced tibial eminence fractures should be treated surgically. Arthroscopy is preferred as it allows for accurate diagnosis and treatment of associated lesions and reduction and fixation of all types of tibial spine fractures while reducing the morbidity associated with open techniques. We report the clinical and radiological results of two cases with displaced tibial eminence fractures, submitted to surgical treatment and the arthroscopic technique of internal fixation with absorbable suture. After a follow-up of 18 months both patients had great improvement. Radiographic exams confirm complete fracture healing at 6 weeks of follow-up. The International Knee Documentation Committee subjective score were excellent (96 and 98 points) and the range of motion of the injured knees were also similar to the no-injured knees. This arthroscopic technique is simple, reproducible and very useful in dealing with these fractures, allowing to obtain excellent functional results.

ACL INJURY AND RETURN TO SPORT

We followed 110 patients who had sustained an acute traumatic Haemarthrosis for a mean of 60 months. The arthrometer measurements within 90 days of injury revealed the injured knee was stable in 35 patients and unstable in 75. Thirty-five unstable patients had an ACL reconstruction within 90 days of injury. Surgical procedures performed &gt;90 days after injury included ligament reconstruction in 35 patients. Factors that correlated with patients who had late surgery for a meniscal tear or an ACL reconstruction &lt; (P 0.05) were preinjury hours of sports participation, arthrometer measurements, and patient age. Follow-up data are presented for the patient’s divided into four groups: I, early stable, no reconstruction; II, early unstable, no reconstruction; III, early reconstruction; and IV, late reconstruction. No patient changed occupation because of the knee injury. Hours per year of sports participation and levels of sports participation decreased in all groups. Joint arthrosis was documented by radiograph and bone scan. Joint surface injury abnormalities observed at surgery and meniscal surgery showed greater abnormalities by radiograph and bone scan scores (P&lt; 0.05). Reconstructed patients had a higher level of arthrosis by radiograph and bone scan. Anterior cruciate ligament injuries are common. The biggest the number of these injuries occur in sports activities, mainly those that involve deceleration, torsion, shear, and jumping movements. In a study on football team injuries in Albania, reported 2.4 injuries per year on an Albanian university football squad. Many patients remain disabled for sport afterwards an ACL injury; others appear to have minimal damage. Some patients develop secondary and degenerative meniscal ttaears knee arthritis; others show little joint deterioration. Few studies have documented the incidence of late meniscal tears after an ACL injury. Due to the variability of patient impairment after ACL injury and the lack of documentation that ACL surgery prevents degenerative arthritis, controversy over indications for ligament surgery. Moreover, a large number of patients do not often follow the entire functional rehabilitation process. The purpose of this prospective study was to document the outcome of the patient with ACL injury and the search for factors identifiable immediately after the injury correlating with a greater risk of functional impairment, secondary meniscus tears and joint arthrosis.

Novel classification for multi-ligament knee injury including both tibiofemoral joint factor and patellofemoral joint factor (193)

Novel classification for multi-ligament knee injury including both tibiofemoral joint factor and patellofemoral joint factor (193)