Pain and knee function in relation to degree of bone bruise after acute anterior cruciate ligament rupture

It is unknown whether the bone bruise that occurs in connection with acute anterior cruciate ligament (ACL) rupture is causing pain and dysfunction. We followed prospectively 17 patients [10 men, seven women, mean age 28 years (range 23-34)] with acute ACL rupture for 2 months. A magnetic resonance imaging (MRI) scan was performed shortly after the injury, and at 2 weeks, 1 month and 2 months. The patients reported the level of pain every day and filled in a Knee injury and Osteoarthritis Outcome Score sheet in connection with MRI. For every MRI of the knee, volume of bone bruise was calculated, and intensity was visually graded. Our study showed a reduction of the pain to 50% approximately 2 weeks after the injury, at which time the bone bruise was at maximum. There was a significant relationship between pain and the volume and intensity of the bone bruise in the medial tibia condyle, as well as pain and the bone bruise volume of the lateral femoral condyle. Patients with bone bruise of the medial tibia and patients with meniscal lesions had more pain. It is suggested that pain and decreased function after acute ACL injury most likely is related to soft tissue and cartilage injury and not to bone bruise.     

The weight-bearing knee after anterior cruciate ligament rupture

Unilateral weight bearing was simulated on 12 cadaver knees to quantitate anterior tibial translation (ATT) after anterior cruciate ligament (ACL) transection and to asses the role of the posteromedial structure and the hamstrings in controlling laxity. With the ACL intact, ATT was 3.5±2.8 mm in extension and 4.3±3.6 mm at 60° flexion. After sectioning the ACL, ATT was 6.5±4.7 mm in extension and 17.5±10 mm at 60° flexion (P=0.001). Applying a force in the hamstrings was unable to correct the pathological ATT observed after ACL section. Partial medial meniscectomy did not increase ATT after the ACL section. Disinsertion of the posterior horn of the medial meniscus and total medial meniscectomy increased ATT significantly compared to isolated ACL section. After ACL transection, sectioning the meniscotibial fibers or posteromedial capsule significantly increased ATT (6.5±0.5 mm in extension). Section of the postero-oblique ligament or popliteus tendon had no effect on ATT.     

Dynamic knee stability after anterior cruciate ligament rupture

A functional classification scheme has been devised to study knee stabilization strategies after anterior cruciate ligament rupture. A screening examination can determine which patients may be candidates for nonsurgical treatment (potential copers). A rehabilitation program that includes support surface perturbations can improve the potential coper's ability to stabilize the knee. Biomechanical, electromyographic, and clinical data support the classification scheme and perturbation training for improving dynamic knee stability.     

Relationship between bone bruise volume and the presence of meniscal tears in acute anterior cruciate ligament rupture

Purpose

To determine whether there is a relationship between the size of the bone bruise volume after an acute anterior cruciate ligament (ACL) rupture and the presence of meniscal tears in the medial and lateral compartment.

Methods

Following Institutional Review Board approval, 50 patients with an acute ACL rupture and MRI imaging within 30 days of injury were identified. Two musculoskeletal radiologists evaluated the lateral and medial menisci and graded them as one of the following: no meniscal tear, tear of one meniscus (medial or lateral) or tear of both menisci (medial and lateral). Sagittal T2 fat-suppressed images were used to calculate bone bruise volume. The relationship between bone bruise volume and the presence of a meniscus tear was calculated.

Results

Forty-three (86 %) patients had a bone bruise, 16 (32 %) patients had no tear, 7 (14 %) patients had lateral meniscus tear, 13 (26 %) patients had medial tear and 14 (28 %) patients had medial and lateral tears. There was a statistically significant difference in femoral bone bruise volume when comparing no meniscal tear to medial and lateral tears as well as when comparing medial or lateral tears to medial and lateral tears.

Conclusion

There is a statistically significant relationship between femoral bone bruise volume and the presence of meniscal tears in ACL injury, especially in the setting of medial and lateral pathology.

Level of evidence

Retrospective cohort study, Level III.     

The effect of proprioceptive knee bracing on knee stability after anterior cruciate ligament reconstruction

BackgroundInjury to the anterior cruciate ligament (ACL) is common among young athletes and can impact knee stability and control. Wearing proprioceptive knee braces can improve knee control and may reduce the risk factors associated with injury and re-injury, although the effect of such braces after ACL reconstruction (ACLR) is unclear.Research questionThis study aimed to determine the effect of proprioceptive knee bracing on knee control and subjective rating of participants post ACLR during three dynamic tasks.MethodsFifteen participants 2–10 years post ACLR performed a slow step down, single leg drop jump, and pivot turn jump with and without a proprioceptive knee brace. Knee kinematics in the sagittal (flexion – extension), coronal (abduction – adduction), and transverse (internal – external rotation) planes were collected using a 3D infrared system. Paired t-tests were performed to explore differences in knee angles and angular velocities between the no brace and brace conditions during the three tasks. After each task, subjective ratings regarding ease of the task were recorded.ResultsThe brace reduced the peak knee external rotation angle and range of motion in the transverse plane during the pivot turn jump task, and significantly increased the maximum knee flexion angular velocity during the single leg drop jump task. The majority of participants reported that tasks were easier to perform with the proprioceptive brace than without.SignificanceThis study confirms that proprioceptive knee braces can significantly influence knee kinematics during dynamic tasks post ACLR. The observed effects were clinically relevant.     

Simultaneous rupture of the anterior cruciate ligament and a knee tumor

We report two patients with simultaneous lesions about the knee; a traumatic injury (acute anterior cruciate ligament rupture) and a musculoskeletal tumour; that may be particularly misleading for the treating surgeon.     

Impact biomechanics of lateral knee bracing. The anterior cruciate ligament

We evaluated the effects of six different prophylactic braces on ACL ligament strain under dynamic valgus loads using a mechanical surrogate limb validated against human cadaveric specimens. Medical collateral ligament and anterior cruciate ligament peak forces, medial collateral ligament and anterior cruciate ligament tension initiation times, and impact safety factors were calculated for both braced and unbraced conditions. These tests were conducted to determine whether or not application of a prophylactic brace might provide protection to the anterior cruciate ligament under valgus loading conditions. The results of this study indicate that those braces that increased impact duration appear to differentially protect the anterior cruciate ligament more than the medial collateral ligament, and that most of the braces tested appear to provide some degree of protection to the anterior cruciate ligament under direct lateral impacts. These findings should be confirmed clinically.     

膝关节急性前交叉韧带撕裂的常见MRI征象分析

目的 :分析膝关节急性前交叉韧带(anterior cruciate ligament,ACL)撕裂的MRI征象,提高对ACL撕裂的术前诊断和评估能力。方法:回顾性分析117例经关节镜或手术证实急性ACL撕裂患者的临床及影像学资料,分析其MRI征象。结果:117例MRI直接征象主要为ACL纤维中断或部分不连续、弥漫性增粗并信号增高、走行异常、胫骨附着处撕脱骨折;间接征象主要为胫、股骨外侧髁的"对吻性"骨挫伤或骨折、后交叉韧带曲率增大、胫骨前移位、内侧副韧带损伤、内侧半月板撕裂。评估分析5种MRI直接征象得出,ACL走行异常具有相对高的诊断敏感度和特异度;5种MRI间接征象均诊断特异度高而敏感度低。结论 :MRI直接征象能较准确地诊断急性ACL撕裂,并评估其撕裂程度,可作为主要诊断依据;而MRI间接征象特异度较高、敏感度相对较低,不能作为主要诊断依据,但对明确诊断具有较大帮助,可作为辅助诊断依据。     

The effect of anterior cruciate ligament graft rotation on knee biomechanics

Purpose

The purpose of this study was to evaluate the effects on knee biomechanics of rotating the distal end of the bone-patellar tendon graft 90° in anatomic single-bundle (SB) anterior cruciate ligament (ACL) reconstruction with a porcine model.

Methods

Twenty (n = 20) porcine knees were evaluated using a robotic testing system. Two groups and three knee states were compared: (1) intact ACL, (2) deficient ACL and (3) anatomic SB ACL reconstruction with (a) non-rotated graft or (b) rotated graft (anatomic external fibre rotation). Anterior tibial translation (ATT), internal (IR) and external rotation (ER) and the in situ tissue force were measured under an 89-N anterior tibial (AT) load and 4-N m internal and external tibial torques.

Results

A significant difference from the intact ACL was found in ATT at 60° and 90° of knee flexion for rotated and non-rotated graft reconstructions (p < 0.05). There was a significant difference in the in situ force from the intact ACL with AT loading for rotated and non-rotated graft reconstructions at 60° and 90° of knee flexion (p < 0.05). Under IR loading, the in situ force was significantly different from the intact ACL at 30° and 60° of knee flexion for rotated and non-rotated graft reconstructions (p < 0.05). There were no significant differences in ATT, IR, ER and the in situ force between rotated and non-rotated reconstructions.

Conclusion

Graft rotation can be used with anatomic SB ACL reconstruction and not have a deleterious effect on knee anterior and rotational biomechanics. This study has clinical relevance in regard to the use of graft rotation to better reproduce the native ACL fibre orientation in ACL reconstruction.

     

Methods to diagnose acute anterior cruciate ligament rupture: a meta-analysis of instrumented knee laxity tests

Purpose

The aims of this meta-analysis were to determine the sensitivity and specificity of the KT 1000 Arthrometer, Stryker Knee Laxity Tester and Genucom Knee Analysis System for ACL rupture. It was hypothesized that the KT 1000 test is the most sensitive and specific. Secondly, it was hypothesized that the sensitivity and specificity of the KT 1000 arthrometer increase when the amount of Newton force is increased.

Methods

An electronic database search was performed using MEDLINE and EMBASE. All cross-sectional and cohort studies comparing one or more instrumented examination tests for diagnosing acute complete ACL rupture in living human subjects to an accepted reference standard such as arthroscopy, arthrotomy and MRI were included.

Results

The sensitivity of the KT 1000 Arthrometer with 69 N was 0.54. With 89 N, the sensitivity was 0.78 and the specificity 0.92, and with maximum manual force, the sensitivity was 0.93 and the specificity 0.93. For the Stryker Knee Laxity Tester, the sensitivity was 0.82 and the specificity 0.90. And for the Genucom Knee Analysis System, the sensitivity was 0.74 and the specificity 0.82.

Conclusion

The KT Arthrometer performed with maximum manual force has the highest sensitivity, specificity, accuracy and positive predictive value for diagnosing ACL rupture.

Level of evidence

Meta-analysis, Level I.     

Eighteen- to twenty-five-year follow-up after acute partial anterior cruciate ligament rupture.

Of 22 consecutive patients with minor knee instability after a partial rupture of the anterior cruciate ligament, all could be reexamined after a mean of 12 years and all but 1 could be reexamined after a mean of 20 years. Three patients needed surgery during the follow-up period, but nobody had an anterior cruciate ligament reconstruction. The Lysholm knee function score was excellent and did not change between 12 and 20 years. Patients had decreased their activities from contact sports before injury to physical fitness activities at the late follow-up. Four patients changed activities because of a knee problem. The quality of life score was somewhat higher than may be expected in an age-matched average population. At late follow-up, eight patients had a 1+ Lachman sign, two a 2+ Lachman sign, and one a positive pivot shift. Also at late follow-up, 7 knees showed no signs of radiographic osteoarthrosis, 10 had Fairbank's signs, and 3 had minor and 1 a major joint space reduction. Of the 12 patients with longitudinal radiographic observation, 3 knees had developed a higher degree of osteoarthrosis, and 9 had remained unchanged. The patients had a mean age of 48 years at the late follow-up. This suggests that the results may be regarded as final outcome after this specific knee injury.     

The effect of anterior cruciate ligament graft orientation on rotational knee kinematics

Purpose

To determine whether coronal graft orientation and tunnel placement for single-bundle anterior cruciate ligament (ACL) reconstruction is associated with tibial rotation excursion during functional activities.

Methods

Eighty-four patients who had undergone ACL reconstruction over a ten-year time span had tibial rotation measured during level walking, using a three-dimensional motion analysis system. Fifty-two patients also had measures taken during the more dynamic task of single-limb landing. During the 10-year period, the position of the graft was deliberately changed from a vertical to more horizontal orientation in the coronal plane. Post-operative radiographs were analysed for the coronal graft orientation and femoral and tibial tunnel positions. Radiographic measurements of graft orientation and tunnel position were then correlated with the amount of tibial rotational excursion recorded during the walking and landing tasks.

Results

For the single-limb landing task, a significant positive correlation was observed between the coronal graft angle and rotational excursion (R = 0.35, R ²  = 0.12, p = 0.01). This indicated greater rotational excursion was associated with vertical graft orientation, but only explained 12 % of the variance. No correlations were found between coronal graft angle and tibial rotation during level walking.

Conclusions

These findings support the notion that ACL graft orientation may play a role in rotational kinematics of the ACL-reconstructed knee, particularly during higher impact activities.

Level of evidence

IV.     

The effect of anterior cruciate ligament trauma and bracing on knee proprioception

We studied the effect that chronic anterior cruciate ligament disruption, functional bracing, and a neoprene sleeve have on knee proprioception by measuring the threshold to detection of passive knee motion in all three conditions. The threshold to detection of passive knee motion was worse in knees with chronic anterior cruciate ligament insufficiency when compared with uninjured knees. This difference was small, on average an additional 0.28 degree of flexion-extension rotation was required for the anterior cruciate ligament-deficient knee before the subject detected motion, and of questionable significance from a clinical and functional perspective. Wearing a functional brace or neoprene sleeve on the anterior cruciate ligament-deficient knee did not significantly change the threshold to detection of passive motion in comparison with the same knee without a brace, although improvements were observed. There was no relationship between the most common clinical means of characterizing altered biomechanics of the anterior cruciate ligament-deficient knee (that is, the magnitude of anterior-posterior knee laxity and the grade of pivot shift) and the threshold to detection of passive knee motion.     

Restoring knee joint kinematics after anterior cruciate ligament injury might inhibit synovial membrane inflammation

Sport Sciences for Health - We developed a novel controlled abnormal joint movement (CAJM) model that controls instability after traditional anterior cruciate ligament transection (ACL-T). We...     

Results of knee manipulations after anterior cruciate ligament reconstructions

We analyzed the results of knee manipulations in 42 knees that had persistent flexion or extension deficits after intraarticular ACL reconstructions. All manipulations were done under a spinal or general anesthetic and, in 10 cases, arthroscopic debridement of adhesions also was performed. The average time from reconstruction to manipulation was 7 months (range, 3 to 14 months) and the average followup was 26 months (range, 6 to 56 months). At manipulation, average flexion was increased from 95 degrees to 136 degrees and average extension from 11 degrees to 3 degrees. In no case was motion gained at the expense of joint stability and, at final followup, average flexion and extension were 127 degrees and 4 degrees, respectively. The final range of motion achieved was not affected by the time to manipulation, severity of premanipulation flexion deficit, or concomitant arthroscopic debridement of adhesions. However, knees with premanipulation extension deficits of greater than or equal to 15 degrees achieved significantly less final extension than knees with lesser premanipulation deficits. Overall, manipulations were a safe and effective method for improving both flexion and extension in 86% of the knees that had restricted motion after ACL reconstructions.     

The effect of anterior cruciate ligament reconstruction on the risk of knee reinjury

BACKGROUND: Although there is evidence that very active, young patients are better served with anterior cruciate ligament reconstruction, there is a lack of objective data demonstrating that future knee injury is prevented by these procedures. HYPOTHESIS: Anterior cruciate ligament reconstruction protects against reinjury of the knee that would require reoperation. STUDY DESIGN: Retrospective cohort study. METHODS: A cohort of 6576 active-duty army personnel who had been hospitalized for anterior cruciate ligament injury from 1990 to 1996 were identified. Using the Total Army Injury and Health Outcomes Database, the authors followed these individuals for up to 9 years and collected clinical, demographic, and occupational data. These data were evaluated with bivariate and multivariable analyses to determine the effect of anterior cruciate ligament reconstruction on the rate of knee reinjury that required operation. RESULTS: Of the 6576 study subjects, 3795 subjects (58%) underwent anterior cruciate ligament reconstruction and 2781 (42%) did not. The rate of reoperation was significantly lower among the anterior cruciate ligament reconstruction group (4.90/100 person-years) compared with those treated conservatively (13.86/100 person-years; P < .0001). Proportional hazard regression analyses adjusted for age, race, sex, marital status, education, and physical activity level confirmed that anterior cruciate ligament reconstruction was protective against meniscal and cartilage reinjury (P < .0001). Secondary medial meniscal injury was more common than secondary lateral meniscal injury (P < .003). Younger age was the strongest predictor of failure of conservative management leading to late anterior cruciate ligament reconstruction (P < .0001). CONCLUSIONS: Anterior cruciate ligament reconstruction protected against reoperation in this young, active population; younger subjects were more likely to require late anterior cruciate ligament reconstruction. CLINICAL RELEVANCE: Strong consideration should be given to anterior cruciate ligament reconstruction after anterior cruciate ligament injury in young, active individuals.