Meniscal injuries associated with acute anterior cruciate ligament tears in alpine skiers

Bone Bruises and Concomitant Meniscus and Cartilage Damage in Anterior Cruciate Ligament Injuries: A Systematic Review and Meta-Analysis

(1) Background: Bone bruises in acute anterior cruciate ligament (ACL) injuries are closely linked to the occurrence of simultaneous meniscal and cartilage damage. Despite the frequent occurrence of associated injuries including bone bruises, meniscus, and cartilage damage in patients with ACL injuries, a systematic review of the relationships between the presence of bone bruises and the extent of meniscus and cartilage injuries has yet to be conducted. (2) Methods: Multiple comprehensive databases, including MEDLINE, EMBASE, and the Cochrane Library, were searched for studies that evaluated the relationship between bone bruises and meniscus or cartilage injuries following ACL injuries. Study selection, data extraction, and meta-analysis were performed. The Methodological Index for Non-Randomized Studies (MINORS) was used for quality assessments, and Review Manager 5.3 was used for data analysis. (3) Results: Data were extracted from 22 studies encompassing a total of 2891 patients with ACL injuries. Among the included studies, six studies investigated the relationships between bone bruises and medial meniscus (MM) or lateral meniscus (LM) injuries, while three studies investigated the relationships between bone bruises and cartilage injuries. There were no significant correlations between the presence of bone bruises and MM injuries (relative risk (RR) = 1.32; p = 0.61). A quantitative analysis indicated that individuals with bone bruises had a 2.71-fold higher likelihood of sustaining LM injuries than those without bone bruises (RR = 2.71; p = 0.0003). The analysis confirmed a significant relationship between bone bruises and cartilage injuries (RR = 6.18; p = 0.003). (4) Conclusions: Bone bruises occur most frequently in the lateral compartment. Bone bruises resulting from ACL injuries are related to accompanying LM injuries and cartilage injuries. Knowing these associations and the frequency of injuries may allow orthopedic surgeons to promptly address ACL-related meniscus and cartilage injuries on MRI results and in future clinical practice.

Treating Combined Anterior Cruciate Ligament and Medial Collateral Ligament Injuries Operatively in the Acute Setting Is Potentially Advantageous

Combined injury of the anterior cruciate ligament (ACL) and medial collateral ligament (MCL) remains among the most common knee injury patterns in orthopaedics. Optimal treatment of grade III MCL injuries is still debated, especially when combined with ACL injury. Most patients with these severe injuries are treated conservatively for at least 6 weeks to allow for MCL healing, followed by delayed ACL reconstruction. Although acute treatment of the MCL was common in the 1970s, postoperative stiffness was frequently reported. Moreover, studies of such treatment failed to show clinical benefits of surgical over conservative treatment, and the MCL exhibited intrinsic healing capacity, leading to the consensus that all MCL injuries are treated conservatively. The current delayed treatment algorithm for ACL-MCL injuries has several disadvantages. First, MCL healing may be incomplete, resulting in residual valgus laxity that places the ACL graft at greater risk of failure. Second, delayed treatment lengthens the overall rehabilitation period, thereby prolonging the presence of atrophy and delaying return to preinjury activity levels. Third, the initial healing period leaves the knee unstable for longer and risks further intra-articular damage. Acute simultaneous surgical treatment of both ligaments has the potential to avoid these shortcomings. This article will review the evolution of treatment of ACL-MCL injuries and explain how it shifted toward the current treatment algorithm. We will (1) discuss why the consensus shifted, (2) discuss the shortcomings of the current treatment plan, (3) discuss the potential advantages of acute simultaneous treatment, and (4) present an overview of the available literature.

Imaging Review of Alpine Ski Injuries

Skiing is a continuously evolving winter sport, responsible for a considerable number of musculoskeletal injuries. Specific injury patterns and mechanisms in the upper and lower extremities, head, and spine are influenced by skier expertise and skill, position during injury, and environmental conditions. Predilection for certain joints and injury patterns have changed over time, largely due to technological advancements in equipment, increased awareness campaigns, and preventive protocols. Knowledge and understanding of these trends and developments can aid the radiologist to reach a timely and accurate diagnosis, thereby guiding clinical management and potentially reducing the overall incidence of debilitation and death.

In recreational alpine skiing, the ACL is predominantly injured in all knee injuries needing hospitalisation

PURPOSE

The knee joint still represents the most frequent anatomical injury location accounting for about one-third of all injuries in recreational alpine skiers. However, comprehensive information on current knee injury patterns in this populations is sparse.

METHODS

During the winter seasons 2016/17 and 2019/20, this retrospective questionnaire-based study was conducted in an Austrian sportclinic situated in a large ski area. Among a cohort of 282 recreational skiers (51.8% females), all injuries were diagnosed by the use of magnetic resonance imaging. Additionally, data were recorded on anthropometric characteristics, the perceived speed at the moment of injury, type of fall, physical fitness, self-reported skill level and risk-taking behaviour.

RESULTS

The anterior cruciate ligament (ACL) was injured in all knee injuries recorded. Of the total study sample, 64.5% (n = 182) were ACL injuries with concomitant injuries and about 35.5% (n = 100) were isolated ACL injuries, not involving any other structures of the knee joint. In general, most common concomitant injury diagnoses among ACL-injured recreational alpine skiers were injuries of the medial collateral ligament (MCL) (n = 92, 50.5%), medial meniscus (MM) (n = 73, 40.1%) and lateral collateral ligament (LCL) (n = 41, 22.5%). No significant differences regarding additionally recorded characteristics were found between ACL-injured individuals with concomitant injuries and those with isolated ACL injury.

CONCLUSIONS

Whereas, before the introduction of carving skis, the MCL was reported being the most common injured part of the knee, currently, the majority of knee injuries are ACL injuries accompanied by injury of other knee joint structures, i.e. the MCL, MM and LCL.

LEVEL OF EVIDENCE

Level III.

Ski and Snowboard - Related Orthopedic Injuries

Participation in skiing and snowboarding continues to increase. Both sports are associated with unique equipment and movement patterns, placing athletes at risk for several characteristic injuries. Although the axial skeleton and extremities are at risk for injury in both sports, skiing and snowboarding are associated with distinctive injury patterns. This article summarizes the epidemiology, risk factors, and specific injuries associated with skiing and snowboarding to better educate orthopedic surgeons regarding diagnosis and treatment of athletes partaking in these sports.

Anterior cruciate ligament tear due to non-contact mode of injury associated with higher incidence of meniscal and chondral damage

BACKGROUND

Forces acting on the knee are different in contact and non-contact mode of injuries causing anterior cruciate ligament (ACL) tear. Purpose of this study was to determine the effect of mode of injury on the occurrence of meniscal tear and chondral damage in ACL tear.

METHOD

72 athletes with acute ACL injury (<3 months) were enrolled in the study. Depending on the mode of injury, athletes were divided into two groups - group A (non-contact mode of injury) and group B (contact mode of injury). 49/72 athletes had the non-contact mode of injury (group A), and 23/72 athletes had contact mode of injury (group B). Meniscal tear and chondral damage seen at the time of ACL reconstruction surgery was noted. All athletes were assessed at 12 months follow-up for return to sports, Lysholm score, and WOMAC score.

RESULTS

In group A, 35/49 (71%) athletes and in group B, 9/23(39%) athletes had meniscal tear (p = 0.009). Medial meniscus was more commonly injured in group A [24/49] as compared to group B (5/23; p = 0.03). Chondral damage was also more commonly seen in group A [26/49] as compared to group B (5/23; p = 0.01). At one-year follow-up, 65% of the athletes from group B returned to sports as compared to 57% of the athletes from group A (p-value = 0.6). WOMAC score in group A and B was 95.5 ± 4.88 and 96 ± 4.39 respectively (p = 0.67). Lysholm score in group A and B was 1.02 ± 1.7 and 0.96 ± 1.2 respectively (p = 0.88).

CONCLUSION

Non-contact mode of injury was associated with a higher incidence of meniscal tear and chondral damage. However, the mode of injury does not affect the functional outcome of ACL reconstruction surgery.

Poorer dynamic postural stability in patients with anterior cruciate ligament rupture combined with lateral meniscus tear than in those with medial meniscus tear

Background

Only limited data are available regarding postural stability between anterior cruciate ligament (ACL)-injured patients with medial meniscus (MM) tear and those with lateral meniscus (LM) tear. The purpose of this study was to compare preoperative postural stability for both involved and uninvolved knees in ACL rupture combined with MM and LM tears. It was hypothesized that there would be a significant difference in postural stability between these two groups.

Methods

Ninety-three ACL-injured patients (53 combined with MM tears vs. 40 combined with LM tears) were included. Static and dynamic postural stability were evaluated with the overall stability index (OSI), anterior–posterior stability index (APSI), and medial–lateral stability index (MLSI) using stabilometry. Knee muscle strength was evaluated using an isokinetic testing device.

Results

In the static postural stability test, none of the stability indices showed significant differences between the two groups for both knees (p > 0.05). In the dynamic postural stability test for involved side knees, the OSI and APSI were significantly higher in the LM tear group compared to the MM tear group (OSI: 2.0 ± 0.8 vs. 1.6 ± 0.5, p = 0.001; APSI: 1.5 ± 0.6 vs. 1.3 ± 0.5, p = 0.023), but not the MLSI (p > 0.05). In the static and dynamic postural stability tests in each group, there were no significant differences between the involved and uninvolved side knees (p > 0.05). There was no significant difference in the knee muscle strength between the two groups (p > 0.05). All postural stability showed no significant correlation with knee muscle strength (p > 0.05).

Conclusion

Dynamic postural stability was poorer in patients with ACL rupture combined with LM tear than in those with MM tear. Therefore, close monitoring for postural stability would be necessary during preoperative and postoperative rehabilitation, especially for patients with ACL rupture combined with LM tear.

Level of evidence: Level III

Anatomic risk factor for meniscal lesion in association with ACL rupture

Background

To assess anatomic risk factors for meniscal lesions in association with acute ACL rupture. The primary hypothesis was that tibiofemoral anatomic measures will be different in those with and without concomitant meniscus tears.

Methods

A retrospective review of patients who underwent acute ACL reconstruction in the department was performed. All patients underwent a postoperative CT scan. The concavity and/or convexity on the femur and the tibia were measured by two blinded observers on the sagittal plane with different ratios, and these measures were compared in patients with and without meniscus tears in each compartment. Intra- and inter-rater reliabilities were assessed.

Results

Four hundred twelve patients (268 males and 144 females) were included from October 2012 to February 2015. One hundred sixty-seven patients had a medial meniscal tear (119 males/48 females), and 100 had a lateral meniscal tear (80 males/20 females). The mean time from injury to surgery was 3 months. The average ICC for all measurements was 0.87 (range 0.82–0.98) indicating good reliability. The medial femoral condyle was noted to be significantly longer than the medial tibial plateau in the sagittal plane in patients with a medial meniscal tear (p = 0.04), and the lateral femoral condyle was noted to be significantly longer than the lateral tibial plateau in the sagittal plane in patients with a lateral meniscal tear (p <  0.001). In addition, a less convex lateral tibial plateau was statistically correlated with a higher risk of lateral meniscal tear (p = 0.001).

Conclusions

A greater anteroposterior length of the medial/lateral femoral condyle relative to the medial/lateral tibial plateau is associated with an increased risk of meniscal lesions in association with acute ACL rupture. The lateral compartment in the male population appears to be the most at risk.

Trial registration

Retrospectively registered on May 12, 2016 (CPP sud-est II CAL n°2016-037)

Risk Factors for Concomitant Collateral Ligament Injuries in Children and Adolescents With Anterior Cruciate Ligament Tears

Background:

Risk factors for concomitant ligament injuries (CLIs) of the lateral collateral ligament (LCL) and medial collateral ligament (MCL) in children and adolescents with anterior cruciate ligament (ACL) tears are unknown.

Purpose:

To determine whether body mass index (BMI), sex, age, and injury mechanism are associated with CLIs in children and adolescents with ACL tears and whether CLIs are associated with meniscal and chondral injuries and a delay to surgery.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

We reviewed the records of patients aged ≤18 years with ACL tears from 2009 through 2013 for sex, age, height, weight, CLI, injury mechanism, intra-articular injury, and time to surgery. Patients were assigned to groups according to the presence of a CLI (CLI group) compared with the presence of an isolated ACL tear (ACL group). BMI was categorized as underweight, normal weight, or overweight/obese. The older group was defined as age ≥14 years for girls and ≥16 years for boys. Logistic regression, Mann-Whitney U tests, and chi-square tests were performed (alpha = 0.05).

Results:

We included 509 patients (267 girls) with a mean age of 15 years (range, 6-18 years) at the time of injury. There were 396 patients (78%) in the ACL group and 113 patients (22%) in the CLI group (90 with MCL, 11 with LCL, and 12 with both MCL and LCL injuries). Groups had similar proportions of overweight/obese patients (P = .619) and girls (P = .104). Older age (odds ratio [OR], 2.0 [95% CI, 1.3-3.3]) and contact injuries (OR, 2.2 [95% CI, 1.4-3.4]) were associated with CLIs. The CLI group had a higher proportion of chondral injuries (P = .001) but not meniscal injuries (P = .295) and presented to surgery earlier than the ACL group (P = .002).

Conclusion:

Older age and contact injuries were associated with CLIs in children and adolescents with ACL tears, whereas BMI category and sex were not. CLIs were associated with a higher proportion of chondral injuries but not meniscal injuries and were not associated with a delay to surgery.

Association of Compartmental Bone Bruise Distribution With Concomitant Intra-articular and Extra-articular Injuries in Acute Anterior Cruciate Ligament Tears After Noncontact Sports Trauma

Background:

Anterior cruciate ligament (ACL) injuries are frequently associated with bone bruises, and their presence may be associated with concomitant intra- and extra-articular injuries.

Purpose:

To investigate the prevalence and pattern of distribution of bone bruises in patients with acute ACL tears from noncontact sports trauma and their association with specific intra- and extra-articular injuries.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

A total of 168 patients underwent magnetic resonance imaging (MRI) within 6 weeks of sustaining an ACL tear. Information regarding their demographics as well as MRI evidence of bone bruise patterns and associated injuries was carefully documented. Univariate and multivariate logistic regression analyses were performed to determine the association between bone bruises and concomitant intra- and extra-articular injuries seen on MRI.

Results:

Bone bruises were observed in 155 (92.3%) of 168 patients. The prevalence of bone bruises was 83.9%, 78.6%, 56.5%, and 29.8% on the lateral tibial plateau, lateral femoral condyle, medial tibial plateau, and medial femoral condyle, respectively. A total of 110 (65.5%) patients had bone bruises in both the medial and lateral compartments of the knee, 41 (24.4%) had isolated lateral compartment bone bruises, 4 (2.4%) had isolated medial compartment bone bruises, and 13 (7.7%) did not have any bone bruises. None of the demographic factors were significantly associated with the presence or absence of bone bruises. The presence of bone bruises was significantly associated with lateral meniscal injuries (P = .05). Lateral compartment bone bruises were significantly associated with lateral meniscal injuries (P = .034), while bone bruises affecting both the lateral and medial compartments were significantly associated with medial collateral ligament (MCL) injuries (P = .044) and lateral collateral ligament (LCL) injuries (P = .038) in addition to lateral meniscal injuries (P = .022).

Conclusion:

Bone bruises are common in patients with acute ACL tears after noncontact sports injuries. The compartmental distribution of bone bruises is associated with concomitant intra- and extra-articular injuries. Bone bruises involving the lateral compartment of the knee are associated with lateral meniscal injuries, while bone bruises involving both the lateral and medial compartments of the knee are associated with MCL and LCL injuries in addition to lateral meniscal injuries.

Comparative postural stability in patients with lateral meniscus versus medial meniscus tears

BACKGROUND

Types of mechanoreceptors may differ between the medial and lateral menisci, suggesting that postural stability may differ between patients with medial and lateral meniscus tears. However, to date, postural stability has not been compared in patients with medial and lateral meniscus tears. This study used stabilometry to compare postural stability in patients with medial and lateral meniscus tears.

METHODS

Postural stability and thigh muscle strength were assessed in 24 patients with medial and 18 patients with lateral meniscus tears. Postural stability was determined by measuring the anteroposterior (APSI), mediolateral (MLSI), and overall (OSI) stability indices using stabilometry. Maximal torque (60°/s) of the quadriceps and hamstring was evaluated using an isokinetic testing device.

RESULTS

The three stability indices, OSI, APSI, and MLSI, in both involved and uninvolved knees were all significantly greater in patients with lateral than with medial meniscus tears. (P<0.001 for all OSI, APSI, and MLSI in both involved and uninvolved knees, except for P=0.005 for MLSI of involved knees). In patients with medial meniscus tears, both OSI (1.4±0.4 vs. 1.1±0.4, P=0.037) and MLSI (0.9±0.3 vs. 0.8±0.3, P=0.041) were significantly higher on the injured than the uninjured side. In patients with lateral meniscus tears, none of the stability indices differed significantly between injured and uninjured knee joints.

CONCLUSION

Postural stability of both the injured and uninjured knee joints was poorer in patients with lateral than with medial meniscus tears.

A Retrospective Analysis of Concurrent Pathology in ACL-Reconstructed Knees of Elite Alpine Ski Racers

Background:

Anterior cruciate ligament (ACL) tear is the most frequent injury in alpine ski racing, and there is a high prevalence of ACL reinjury. Limited data exist on the concurrent pathology with primary ACL tears in elite alpine ski racers and the magnitude of injury progression after primary ACL reconstruction (ACLR).

Purpose:

To evaluate (1) the involvement of intra-articular and multiligament pathologies at the time of primary ACLR, (2) the subsequent progression in meniscal/chondral injuries, and (3) the occurrence of ACL reinjury in elite alpine ski racers.

Study Design:

Case series; Level of evidence, 4.

Methods:

Primary ACLR operative reports (n = 28) were obtained for 32 elite alpine ski racers along with the reports of 20 operative procedures that occurred subsequent to primary ACLR. Operative reports were evaluated to identify the presence/location of multiligament injury, meniscal tears, and chondral lesions.

Results:

At the time of primary ACLR, a majority of knees (82%; 23/28) demonstrated concurrent injury compared with isolated ACL tears; 32% of knees sustained multiligament injuries (9/28), and 8 involved the ipsilateral medial collateral ligament (MCL). Of the ACL-injured knees, 54% had chondral lesions, of which 73% were sustained in the lateral knee compartment, and 82% of meniscal tears (14/17) were complex in nature. Bilateral ACL tears were seen in 22% of the participants, and 28% underwent ACL revision. In the case of ACL revision or future meniscal/chondral surgery, 60% of meniscal tears and 80% of chondral lesions had worsened since the time of primary ACLR.

Conclusion:

Concurrent injury was common in this group of elite ski racers. Primary ACL tears were typically accompanied by lateral compartment chondral lesions and complex meniscal tears that worsened over time. ACL/MCL tears were the most common multiligament injury pattern.

Acute MCL and ACL injuries: first results of minimal-invasive MCL ligament bracing with combined ACL single-bundle reconstruction

BACKGROUND

There is an on-going discussion whether to operatively treat combined grade II and III lesions of the medial collateral ligament (MCL) with anterior cruciate ligament (ACL) in the acute phase rather than conservative treatment of the MCL lesion with a delayed unitary ACL replacement. Another issue is the question how to technically address these MCL lesions. The aim of this study was, therefore, to analyze the results of simultaneous ACL replacement (hamstrings) in a single-bundle technique with a simultaneous MCL ligament bracing procedure.

METHODS

In this prospective non-randomized trial,, 16 patients were included with grade II and III lesions of the MCL. Surgical treatment was performed within 14 days (mean 10.4 days, SD ±2.3 days) by one single expert orthopedic surgeon using the semitendinosus tendon and Rigidfix® system for femoral and tibial fixation and 3.5 mm screws with one 1.3 mm PDS Cord for minimal-invasive MCL ligament bracing with screw fixation. Knee stability was measured with the Rolimeter® and KT-1000®. MCL stability was assessed in clinically and radiographically with valgus stress projections.

RESULTS

The mean patient age was 36.4 with six female and ten male patients. There were no surgical complications such as infections or healing disturbances. Mean operation time was 64 ± 6 min. The arthrofibrosis rate was 0 %. Medial knee stability was normal in full extension for all cases with no intra-individual side-to-side difference. Radiological assessed MCL stability revealed Δ values with a mean of 1.1 ± 1.3 mm compared to the contra-lateral side. The Lachman Test revealed a side-to-side difference of 1.6 mm with the KT-1000® and 2.6 ± 0.9 mm when measured with the Rolimeter®. Subjective clinical assessment revealed good results with a mean Lysholm Score of 89.1 points.

CONCLUSION

Acute ACL replacement and MCL ligament bracing with this novel technique revealed in this study good clinical results and objective restored knee stability without cases of knee stiffness or arthrofibrosis. The remarkable shortcoming is the small cohort number making further studies necessary.

A Case-Control Study Comparing Bone Bruising and Intra-articular Injuries in Patients Undergoing Anterior Cruciate Ligament Reconstruction With and Without Medial Collateral Ligament Tears

Background:

Concomitant injuries can occur in patients with combined anterior cruciate ligament (ACL) and medial collateral ligament (MCL) tears; however, no studies have compared these injuries in patients undergoing ACL reconstruction with an MCL tear to those with an intact MCL.

Purpose:

To compare bone bruising, meniscus tears, and chondral lesions in patients undergoing ACL reconstruction with an MCL tear (cases) to those with an intact MCL (controls).

Study Design:

Case-control study; Level of evidence, 3.

Methods:

Thirty-two cases and 352 controls were identified from a prospective registry. Bone bruising was confirmed on magnetic resonance imaging, and meniscus tears and chondral lesions were confirmed arthroscopically. Demographics and concomitant injuries were compared between cases and controls using exact chi-square tests. Multivariate logistic regression was used to calculate odds ratios (ORs) and 95% CIs adjusted for age, sex, body mass index, and mechanism and type of injury.

Results:

Cases had significantly more contact injuries than controls (58.1% vs 21.3%, P < .0001). The prevalence and odds of bone bruising of the lateral tibial plateau (89.7% vs 84.6%; P = .59; OR, 3.53; 95% CI, 0.45-27.71), lateral femoral condyle (82.8% vs 72.8%; P = .28; OR, 1.94; 95% CI, 0.64-5.88), medial tibial plateau (20.7% vs 31.7%; P = 0.29; OR, 0.53; 95% CI, 0.19-1.53), and medial femoral condyle (6.9% vs 8.3%; P ≥ .999; OR, 1.07; 95% CI, 0.21-5.40) did not differ significantly between cases and controls. The prevalence and odds of lateral meniscus tears (53.3% vs 43%; P = .34; OR, 1.85; 95% CI, 0.76-4.52), medial meniscus tears (31.3% vs 33.5%; P = .85; OR, 0.90; 95% CI, 0.37-2.21), and chondral lesions (16% vs 10.8%; P = .50; OR, 0.70; 95% CI, 0.15-3.21) also did not significantly differ between cases and controls.

Conclusion:

ACL-MCL injuries were most often due to a contact mechanism, whereas ACL tears without associated MCL injury were more frequently due to a noncontact mechanism. However, there were no significant differences in concomitant injuries in ACL-MCL knees versus ACL knees.

Squat Winnowing: Cause of Meniscus Injuries in Non-Athletic Females

Background:

Sports activities were thought to be the major cause of meniscus injury in both men and woman, but our observations of non-athletic females show that the cause of meniscus injury was unrelated to any type of sports activity.

Objectives:

This study revealed squat winnowing to be a major cause of meniscus injury in non-athletic females.

Patients and Methods:

This retrospective study was conducted in a tertiary care orthopaedic hospital which caters to a population of 10 million people. We assessed 120 non-athletic females who had received treatment in our hospital over a period of 2 years. The most probable cause of knee injury, per initial patient history, was recorded for all non-athletic females who presented clinical signs and symptoms of meniscus injury. The diagnoses were confirmed by relevant MRI and arthroscopy of patients’ knees. All females who engaged in athletic activity and other females with unrelated, non-traumatic knee pathologies were excluded from the study.

Results:

Through our study, we found that 42% (n = 50) of females suffered an injury during squat winnowing of rice, either at home or at work. Another 29% (n = 35) of females cited a history of slipping and spraining their knee as a cause of knee injury, while 19% (n = 16) of females suffered a knee injury during complex accidents such as a traffic accident. Finally, 13% (n = 16) of the females had no definite history of knee injury.

Conclusions:

Our observations add to the knowledge base of the various causes of meniscus tears; this study also revealed that socio-cultural factors influence and contribute to the mechanism of various types of knee injury.

Meniscal tears and articular cartilage damage in the dislocated knee

PURPOSE

Knee dislocations can cause significant damage to intra-articular knee structures, but currently there are limited data reporting articular cartilage and meniscal injuries in this setting. The purpose of this study is to (1) report the rate of concomitant intra-articular injuries at the time of multiligament reconstruction for knee dislocation, (2) determine whether the pattern of ligament injury is associated with the presence of chondral and meniscal injuries, and (3) assess the relationship between timing of surgery and incidence of chondral and meniscal injuries.

METHODS

The records of patients who sustained a knee dislocation between 1992 and 2013 were retrospectively reviewed. Patients included for further review had a PCL-based multiligament knee injury or a minimum of three disrupted ligaments, both indicative of knee dislocation. Patient demographics, ligament injury patterns, meniscal tears and chondral injuries at arthroscopy, and interval from injury to surgery were recorded. Early surgical intervention was defined as <3 months, delayed was between 3 and 12 months, and chronic was >12 months. Data analysis compared ligament injury pattern with chondral and meniscal injuries, as well as the rates of intra-articular injury by timing of surgery.

RESULTS

One-hundred and twenty-one patients (122 knees) were included (93 males, 28 females) with a median age at time of surgery of 31 years (range 15-62). Ninety-three knees (76 %) had associated chondral or meniscal injury. Sixty-seven knees (55 %) presented with meniscal tears (26 isolated medial, 27 isolated lateral, and 14 combined medial/lateral), while 52 knees (48 %) had chondral damage, most commonly in the medial compartment. Schenck classification as well as side of injury did not demonstrate consistent relationships with intra-articular injury. A higher incidence of damage to the lateral femoral condyle (20 % vs 3 %; p = 0.02), lateral tibial plateau (20 % vs 2 %; p < 0.01), and patella (40 % vs 13 %; p = 0.01) was found in the chronic group compared to the early group. The chronic group contained significantly more patients with bicompartmental and tricompartmental chondral lesions (25 % vs 6 %; p = 0.03 and 10 % vs 0 %; p = 0.02, respectively).

CONCLUSION

Meniscal tears and chondral damage occur frequently in patients with a knee dislocation. A longer interval from injury to surgical reconstruction is associated with higher rates of articular cartilage lesions, especially in multiple compartments.

LEVEL OF EVIDENCE

IV.

Efficacy of P188 on lapine meniscus preservation following blunt trauma

Traumatic injury to the knee leads to the development of post-traumatic osteoarthritis. The objective of this study was to characterize the effects of a single intra-articular injection of a non-ionic surfactant, Poloxamer 188 (P188), in preservation of meniscal tissue following trauma through maintenance of meniscal glycosaminoglycan (GAG) content and mechanical properties. Flemish Giant rabbits were subjected to a closed knee joint, traumatic compressive impact with the joint constrained to prevent anterior tibial translation. The contralateral limb served as an un-impacted control. Six animals (treated) received an injection of P188 in phosphate buffered saline (PBS) post trauma, and another six animals (sham) received a single injection of PBS to the impacted limb. Histological analyses for GAG was determined 6 weeks post trauma, and functional outcomes were assessed using stress relaxation micro-indentation. The impacted limbs of the sham group demonstrated a significant decrease in meniscal GAG coverage compared to non-impacted limbs (p<0.05). GAG coverage of the impacted P188 treated limbs was not significantly different than contralateral non-impacted limbs in all regions except the medial anterior (p<0.05). No significant changes were documented in mechanics for either the sham or treated groups compared to their respective control limbs. This suggests that a single intra-articular injection of P188 shows promise in prevention of trauma induced GAG loss.

Clinical, radiological, and morphological evaluations of posterior horn tears of the lateral meniscus left in situ during anterior cruciate ligament reconstruction

BACKGROUND

Recent studies have shown that lateral menisci have a higher healing potential and that they can be treated successfully without symptoms by being left in situ during anterior cruciate ligament (ACL) reconstruction. However, few studies have reported morphological results.

HYPOTHESIS

Stable posterior horn tears of the lateral meniscus left in situ during ACL reconstruction could be healed spontaneously and would result in not only successful clinical outcomes but also morphological restoration.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Among 367 patients who underwent primary ACL reconstruction between 2008 and 2010, 53 patients who had lateral meniscus tears that were left in situ were analyzed. These patients were evaluated subjectively and radiologically and compared with a matched control group that underwent ACL reconstruction without any other structural disorders. Of the 53 patients with stable posterior horn tears of the lateral meniscus left in situ, 28 patients were assessed by second-look arthroscopic surgery and magnetic resonance imaging (MRI).

RESULTS

The mean follow-up of the study group and the control group was 36.47 and 37.26 months, respectively. There were no statistical differences in postoperative clinical outcomes between the 2 groups. Clinical results of both groups including the Lysholm score, Tegner activity score, and International Knee Documentation Committee (IKDC) score significantly improved. In the subgroup composed of 28 patients, follow-up MRI showed 25 (89%) and 24 (86%) healed menisci in sagittal and coronal views, respectively. Twenty-one (75%) were considered to be completely healed, and 5 (18%) were incompletely healed on second-look arthroscopic surgery.

CONCLUSION

Stable posterior horn tears of the lateral meniscus left in situ at the time of ACL reconstruction revealed successful clinical outcomes compared with isolated ACL injuries and showed considerable healing and functional restoration of tears with repeat MRI and second-look arthroscopic surgery. Therefore, leaving stable posterior horn tears of the lateral meniscus in situ during ACL reconstruction should be considered.

Can rotatory knee laxity be predicted in isolated anterior cruciate ligament surgery?

PURPOSE

Despite the overall success of the surgical anterior cruciate ligament (ACL) reconstruction, some patients still present with instability symptoms even after the surgery, mainly due to the presence of associated lesions. At present, the pivot shift test has been reported to be the benchmark to assess rotatory knee laxity. The purpose of this study was to quantitatively evaluate rotatory knee laxity at time-zero in order to determine whether detected post-reconstruction laxity was predictable by its value measured before the reconstruction, which was hypothized to be influenced by the presence of associated lesions.

METHODS

Rotatory knee laxity was retrospectively analysed in 42 patients, including two different ACL reconstructions. The maximal anterior displacement and the absolute value of the posterior acceleration reached during the reduction of the tibial lateral compartment were intra-operatively acquired by using a navigation system and identified as discriminating parameters. For each parameter, statistical linear regression analysis (line slope and intercept) was performed between pre- and post-reconstruction values.

RESULTS

No statistically significant influence of the initial posterior acceleration on the post-reconstruction outcome was found (line slope, p > 0.05), although a statistically significant line intercept was indeed identified (p < 0.001). A statistically significant influence on the surgery outcome was instead found for the initial value of the anterior tibial displacement (line slope = 0.39, p = 0.004), meaning that, on average, about 40 % of the post-reconstruction lateral compartment displacement could be explained by the corresponding pre-reconstruction value. Both of these findings highlighted the importance of intra-operative quantification of rotatory knee laxity to identify correct indications for the surgery.

CONCLUSIONS

This study provided important implications for the future possibility of defining a quantifying tool able to assess rotatory knee laxity during ACL reconstruction. This could allow detection of additional injuries to secondary restraints by easily performing rotatory knee laxity tests, which in turn could reduce post-surgical recurrence of knee instability.

Defining the terms acute and chronic in orthopaedic sports injuries: a systematic review

BACKGROUND

Although many authors report on acute injuries and chronic injuries in the orthopaedic literature, the actual terms are seldom explicitly defined.

HYPOTHESIS

Much of the literature pertaining to sports injuries that are acute or chronic does not define these terms. It is believed that definitions will provide clarity and specificity in future literature.

STUDY DESIGN

Systematic review.

METHODS

A systematic review of 116 articles was conducted to determine whether and how the terms acute and chronic were defined as they pertain to several commonly treated conditions: Achilles tendon rupture, distal biceps tendon rupture, pectoralis major tendon rupture, anterior cruciate ligament (ACL) tear, anterior shoulder instability, and acromioclavicular (AC) joint dislocation. Articles were isolated from various databases and search engines by use of keywords to identify relevant literature.

RESULTS

This study determined that the terms acute and chronic for each injury are defined, respectively, as follows: Achilles tendon rupture: <1 week, >4 weeks; distal biceps tendon rupture: <6 weeks, >12 weeks; pectoralis major tendon rupture: <6 weeks, >6 weeks; ACL tear: <6 weeks, >6 months; anterior shoulder instability: <2 weeks, >6 months; AC joint dislocation, <3 weeks, >6 weeks.

CONCLUSION

The current literature varies greatly in defining the terms acute and chronic in common sports injuries. The vast majority of authors imply these terms, based on the method of their studies, rather than define them explicitly. Injuries involving tendons showed greater consistency among authors, thus making a definition based on consensus easier to derive. The literature on ACL and shoulder instability in particular showed great variability in defining these terms, likely representing the more complex nature of these injuries and the fact that timing of surgery in the majority of patients does not particularly affect the complexity of the surgical approach and treatment.

CLINICAL RELEVANCE

Defining injuries as acute or chronic is clinically relevant in many cases, particularly concerning tendon injuries, where these terms have implications regarding the anatomic pathologic changes and tissue quality, which may necessitate augmentation and alter the initial surgical plan. In cases where these terms are less pertinent to operative treatment considerations, they bring clarity to the discussion of the acuity of the injury (as it pertains to time from insult).

Diagnosis of ACL and meniscal injuries: MR imaging of knee flexion versus extension compared to arthroscopy

The aim of the study was to evaluate whether MR Imaging of the knee at 30° and 55° of flexion can improve the diagnosis of anterior cruciate ligament and menisci injuries compared to arthroscopy and imaging during extension of the knee joint. Knee joints from 40 patients with clinical suspicion of an anterior cruciate ligament (ACL) rupture were examined using MRI while the knee joint was either extended or flexed at 30° and 55° of knee flexion. A standard MR knee coil was used at extension, whereas at 30° and 55° of flexion a non-metallic positioning device and a flexible surface coil was placed ventral to the patella. Sagittal T2-weighted TSE sequences were acquired. In 29 of 40 patients, arthroscopy results were compared to the MRI examinations. Image quality of MRI examinations was evaluated using a three-point rating scale in a blinded fashion. Images were compared between groups and rated as better quality, same quality, or worse quality. Additionally, each angle MRI was compared to arthroscopy results. Partial ACL ruptures were diagnosed with 63% accuracy using MR imaging at 30° and 55° of knee flexion compared to 50% accuracy during knee extension. MRI imaging of complete ACL ruptures resulted in 83% accuracy of diagnosis when imaged at 30° flexion, 93% accuracy at 55° flexion, and 83% accuracy at extension. The accuracy of diagnosing medial meniscus lesions was 73% at extension, 64% at 30° flexion and 73% at 55° of flexion. MR imaging was only able to diagnose lateral meniscus tears with 55% accuracy in all three knee positions. The diagnosis of meniscal tears was more difficult due to small peripheral tears. The improved results in the diagnosis of ACL tears in response to 30° flexion and in particular in response to 55° flexion were based on the fact that the anterior cruciate ligament moved further away from the intercondylar roof with increased knee flexion. During flexion the ligament tension decreased, which causes the anterior cruciate ligament to have cylindrical shape and therefore made visualization of the injury easier. In conclusion, MR Imaging of the knee at 55° of flexion and less at 30° of flexion allows an improved diagnosis of injuries to the anterior cruciate ligament as compared to MRI examinations at extension. The diagnosis of meniscal injuries, however, was not superior at both flexion positions compared to commonly performed examinations at knee extension.

Knee joint examinations by magnetic resonance imaging: The correlation of pathology, age, and sex

Aims:

The aim of our study was to investigate the incidence and coexistence of multiple knee joint pathologies and the distribution of knee joint pathologies according to age and sex.

Patients and Methods:

A retrospective analysis was performed using the clinical data of patients evaluated with magnetic resonance imaging (MRI) of the knee joint. Data from 308 patients examined between August 2002 and July 2003 were included into this study. A Pearson correlation analysis was performed to examine the relationship between the pathological findings and the age and sex of the patients.

Results:

The ages of the patients ranged between 1 and 74 years (mean: 43.3 years). Age was significantly correlated with meniscal degeneration and tears, medial collateral ligament degeneration, parameniscal cyst, and chondromalacia patellae. There was a significant correlation between male gender and anterior cruciate ligament injury. Meniscal injury was significantly correlated with bursitis, as well as medial collateral ligament injury. Bone bruise was significantly correlated with medial collateral ligament injury, lateral collateral ligament injury, Baker's cyst, and anterior cruciate ligament injury. Chondromalacia patellae was significantly correlated with anterior cruciate ligament injury, patellae alta, and osteochondral lesion. Bursitis (in 53.2% of the patients) followed by grade-II meniscal degeneration (in 43% of the patients) were the most common knee pathologies observed by MRI.

Conclusions:

MRI findings of select knee pathologies are significantly correlated with each other and the age and sex of the patient.

Simulation of Anterior Cruciate Ligament Deficiency in a Musculoskeletal Model with Anatomical Knees

Abnormal knee kinematics and meniscus injury resulting from anterior cruciate ligament (ACL) deficiency are often implicated in joint degeneration even though changes in tibio-femoral contact location after injury are small, typically only a few millimeters. Ligament reconstruction surgery does not significantly reduce the incidence of early onset osteoarthritis. Increased knowledge of knee contact mechanics would increase our understanding of the effects of ACL injury and help guide ACL reconstruction methods. Presented here is a cadaver specific computational knee model combined with a body-level musculoskeletal model from a subject of similar height and weight as the cadaver donor. The knee model was developed in the multi-body framework and includes representation of the menisci. Experimental body-level measurements provided input to the musculoskeletal model. The location of tibio-menisco-femoral contact as well as contact pressures were compared for models with an intact ACL, partial ACL transection (posterolateral bundle transection), and full ACL transection during a muscle driven forward dynamics simulation of a dual limb squat. During the squat, small changes in femur motion relative to the tibia for both partial and full ACL transection push the lateral meniscus in the posterior direction at extension. The central-anterior region of the lateral meniscus then becomes “wedged” between the tibia and femur during knee flexion. This “wedging” effect does not occur for the intact knee. Peak contact pressure and contact locations are similar for the partial tear and complete ACL transection during the deep flexion portion of the squat, particularly on the lateral side. The tibio-femoral contact location on the tibia plateau shifts slightly to the posterior and lateral direction with ACL transection.

Meniscal tear repaired with Fast-Fix sutures: clinical results in stable versus ACL-deficient knees

AIM

The aim of this prospective study was to analyze the results of meniscal tears repaired with Fast-Fix All-inside suture in stable versus anterior cruciate ligament (ACL)-deficient knees.

PATIENTS

Forty patients, everybody professional players, all underwent arthroscopic surgery, were divided into two groups and followed-up for at least 24 months. Group A (stable knee affected with isolated meniscal tears) consisted of 20 patients treated exclusively with Fast-Fix suture. Group B (ACL-deficient knees affected with meniscal tears) consisted of 20 patients in which we performed a Fast-Fix suture with concurrent ACL reconstruction (hamstring duplicated). Comparing both Groups together, we have noticed that the good clinical result of meniscal sutures with ACL reconstruction associated has occurred faster than isolated meniscal suture, regardless of the meniscus, the knee, and age of the patient. In fact 6 months after surgery, in Group A, there was a success by 65% against 85% for the Group B with 8.3 points International Knee Documentation Committee (IKDC) difference in favor of the latter. Whereas 24 months after surgery, the percentage was increased achieving 90% in Group A and 95% in Group B with 12.6 points IKDC difference in favor of the Group B. A statistical analysis of variable, both after 6 and 24 months, showed a significant improvement of knee conditions for patients with ACL reconstruction.

CONCLUSION

In conclusion, other than observing the better results in meniscal tears with ACL-deficient knee, we observed that among all cases the best healing occurred in patients affected by meniscal longitudinal vertical tears located in Red-Red zone of external meniscus with an extension of 10 mm in ACL-deficient knee, treated with Fast-Fix suture and ACL reconstruction associated.

Does chronic medial collateral ligament laxity influence the outcome of anterior cruciate ligament reconstruction?: a prospective evaluation with a minimum three-year follow-up

We have shown in a previous study that patients with combined lesions of the anterior cruciate (ACL) and medial collateral ligaments (MCL) had similar anteroposterior (AP) but greater valgus laxity at 30° after reconstruction of the ACL when compared with patients who had undergone reconstruction of an isolated ACL injury. The present study investigated the same cohort of patients after a minimum of three years to evaluate whether the residual valgus laxity led to a poorer clinical outcome. Each patient had undergone an arthroscopic double-bundle ACL reconstruction using a semitendinosus-gracilis graft. In the combined ACL/MCL injury group, the grade II medial collateral ligament injury was not treated. At follow-up, AP laxity was measured using a KT-2000 arthrometer, while valgus laxity was evaluated with Telos valgus stress radiographs and compared with the uninjured knee. We evaluated clinical outcome scores, muscle girth and time to return to activities for the two groups. Valgus stress radiographs showed statistically significant greater mean medial joint opening in the reconstructed compared with the uninjured knees (1.7 mm (SD 0.9) versus 0.9 mm (SD 0.7), respectively, p = 0.013), while no statistically significant difference was found between the AP laxity and the other clinical parameters. Our results show that the residual valgus laxity does not affect AP laxity significantly at a minimum follow up of three years, suggesting that no additional surgical procedure is needed for the medial collateral ligament in combined lesions.

Bone contusion and associated meniscal and medial collateral ligament injury in patients with anterior cruciate ligament rupture

BACKGROUND

The present study examined the prevalence of bone contusions in patients with anterior cruciate ligament (ACL) injury as well as its association with tears of the lateral meniscus, medial meniscus, and medial collateral ligament (MCL).

METHODS

Eighty-one patients with an arthroscopy-proven ACL rupture for whom magnetic resonance images (MRI) were acquired within six weeks after the initial trauma were examined. The bone contusions on the lateral femoral condyle, lateral aspect of the tibial plateau, medial femoral condyle, and medial aspect of the tibial plateau were documented. The injury to MCL was also observed with MRI. The tears of the lateral meniscus and medial meniscus were detected during arthroscopy. The prevalence of lateral meniscus, medial meniscus, and MCL injuries was compared with the existence of the bone contusions.

RESULTS

Sixty-eight (84%) of the eighty-one knees had bone contusions on magnetic resonance imaging. The prevalence of bone contusions was 68%, 73%, 24%, and 26% in the lateral femoral condyle, lateral aspect of the tibial plateau, medial femoral condyle, and medial aspect of the tibial plateau, respectively. There were two fractures of the posterolateral aspect of the tibial plateau and two fractures of the posteromedial aspect of the tibial plateau. The overall prevalences of injury to the lateral meniscus and medial meniscus were 54% (forty-four of eighty-one) and 51% (forty-one of eighty-one), respectively. The prevalence of MCL injuries was 22% (eighteen of eighty-one). The prevalences of lateral meniscus (p = 0.010), medial meniscus (p = 0.011), and MCL (p = 0.066) injuries increased as the bone contusion progressed from being absent, to involving only the lateral compartment, and finally to involving both lateral and medial compartments.

CONCLUSIONS

Bone contusions were prevalent in patients with ACL ruptures, and injuries of the menisci and the MCL tended to increase with the progression of bone contusion. The contrecoup mechanism of bone contusion on the medial compartment resulting from an ACL injury was supported. These results suggest that a higher-energy injury led to a more extensive bone contusion and a greater prevalence of associated injury of other anatomic structures in the knee.

The knee meniscus: structure-function, pathophysiology, current repair techniques, and prospects for regeneration

Extensive scientific investigations in recent decades have established the anatomical, biomechanical, and functional importance that the meniscus holds within the knee joint. As a vital part of the joint, it acts to prevent the deterioration and degeneration of articular cartilage, and the onset and development of osteoarthritis. For this reason, research into meniscus repair has been the recipient of particular interest from the orthopedic and bioengineering communities. Current repair techniques are only effective in treating lesions located in the peripheral vascularized region of the meniscus. Healing lesions found in the inner avascular region, which functions under a highly demanding mechanical environment, is considered to be a significant challenge. An adequate treatment approach has yet to be established, though many attempts have been undertaken. The current primary method for treatment is partial meniscectomy, which commonly results in the progressive development of osteoarthritis. This drawback has shifted research interest toward the fields of biomaterials and bioengineering, where it is hoped that meniscal deterioration can be tackled with the help of tissue engineering. So far, different approaches and strategies have contributed to the in vitro generation of meniscus constructs, which are capable of restoring meniscal lesions to some extent, both functionally as well as anatomically. The selection of the appropriate cell source (autologous, allogeneic, or xenogeneic cells, or stem cells) is undoubtedly regarded as key to successful meniscal tissue engineering. Furthermore, a large variation of scaffolds for tissue engineering have been proposed and produced in experimental and clinical studies, although a few problems with these (e.g., byproducts of degradation, stress shielding) have shifted research interest toward new strategies (e.g., scaffoldless approaches, self-assembly). A large number of different chemical (e.g., TGF-β1, C-ABC) and mechanical stimuli (e.g., direct compression, hydrostatic pressure) have also been investigated, both in terms of encouraging functional tissue formation, as well as in differentiating stem cells. Even though the problems accompanying meniscus tissue engineering research are considerable, we are undoubtedly in the dawn of a new era, whereby recent advances in biology, engineering, and medicine are leading to the successful treatment of meniscal lesions.

Regional and zonal histo-morphological characteristics of the lapine menisci

The menisci have crucial weight-bearing roles in the knee. Regional variations in structure and cellularity of the meniscus have only been minimally investigated. Therefore, the goal of this study was to illustrate the regional cell density, tissue area, and structure of healthy lapine menisci. Skeletally mature Flemish Giant rabbits were used for this study. Upon sacrifice, menisci were removed, fixed in formalin, and cryosectioned. Histological analysis was performed for the detection of sulfated glycosaminoglycans (GAG), collagen Types I and II, cellular density, and tissue area. ANOVA and paired t tests were used for testing of statistical significance. Glycosaminoglycan coverage of the medial meniscus significantly varied between regions, with the anterior region demonstrating significantly more GAG coverage than the posterior region. Inter- and intra-meniscal comparisons revealed variations between zones, with trends that outer zones of the medial menisci had less GAG coverage. Collagen Types I and II had marked characteristics and varying degrees of coverage across regions. Tissue area varied between regions for both medial and lateral menisci. Cellular density was dependent on region in the lateral meniscus. This is the first study to illustrate regional and zonal variation in glycosaminoglycan coverage, size, and cellular density for healthy lapine meniscal tissue. This data provides baseline information for future investigations in meniscal injury models in rabbits.

Meniscal injuries in the young, athletically active patient

Meniscal injuries are common in young physically active individuals, particularly those who are involved in contact level 1 sports that involve frequent pivoting, such as soccer and American football. This is a unique population because of their high physical activity at a young age, and it is important that correct diagnosis and appropriate treatment are provided, as the medial and lateral menisci are essential for normal knee function. In this article, we review the anatomy and function of the meniscus, the epidemiology of meniscal tears, and mechanism(s) of injury. Important concomitant injuries are also discussed. When making a diagnosis, relevant patient history, physical examination, and appropriate imaging studies are required. Nonoperative treatment is rarely successful for treating meniscal tears in young athletes, and therefore repair of the torn menisci is often required. We also discuss partial resection (which should only be performed when repair is not possible), as well as rehabilitation protocols after repair has been performed. All of these factors associated with meniscal injuries are important for a physician when diagnosing and treating these often complex injuries.

Traumatic anterior cruciate ligament tear and its implications on meniscal degradation: a preliminary novel lapine osteoarthritis model

BACKGROUND

Injury patterns of the meniscus following impact trauma resulting in anterior cruciate ligament (ACL) rupture are not well understood. This study explored the spatial and temporal distribution of meniscal tears in a novel in vivo lapine model.

METHODS

Skeletally mature Flemish Giant rabbits were subjected to either tibiofemoral impaction resulting in ACL rupture or surgical ACL transection. Meniscal damage was assessed acutely and after 12 wk for traumatically torn, and after 12 wk in ACL transected animals. Morphological grading was assessed using previously established criteria, and descriptions of meniscal damage were diagnosed by a Board certified orthopedist. Histological assessment was also made on 12 wk traumatically torn and ACL transected animals using Fast-Green/Safranin-O staining.

RESULTS

Traumatic ACL rupture resulted in acute tears predominately in the lateral menisci. Animals subjected to both surgical transection and traumatic ACL rupture experienced degradation of the lateral and medial menisci 12 wk after injury. However, traumatic ACL rupture resulted in acute lateral damage and chronic degradation of the menisci, as well as more severe degradation of the menisci 12 wk after injury.

CONCLUSIONS

This study showed that unconstrained high-intensity impacts on the tibiofemoral joint lead to meniscal damage in conjunction with ACL ruptures. Both acute and chronic changes to the menisci following traumatic impaction were observed. This research has implications for the future use of lapine models for osteoarthritis, as it incorporates traumatic loading as a more realistic mode contributing to the progression of osteoarthritis (OA) compared to surgically transected models.

Displacement of the posterior horn of the lateral meniscus into posterolateral compartment: an unusual injury pattern

We report a case of acute ACL injury with an unusual lateral meniscal tear pattern. The entire posterior horn of the lateral meniscus was avulsed from its attachments while remaining in continuity with the body of the meniscus. It was displaced posteriorly and laterally to the popliteus tendon so that it was not immediately visible at the time of arthroscopy. This type of displacement of the posterior horn of the lateral meniscus is difficult to identify at arthroscopy and has not previously been described in the literature to our knowledge. We recommend to surgeons who encounter an absent posterior horn of the lateral meniscus to consider this injury pattern.

The efficacy of magnetic resonance imaging in acute multi-ligament injuries

This study compares MRI with examination under anaesthesia to surgical findings in evaluating soft tissue injuries in acute multi-ligament knee trauma. Pre-operative MRI was done for 44 patients who underwent surgery for grade III ACL and grade III medial collateral ligament (MCL) injury. In 21 cases both ACL and MCL were treated surgically, but in 23 only ACL. Intra-operative and MRI findings were compared. Accuracy of MRI for medial meniscal tears was 88.6%, sensitivity 80%, and specificity 91.2%; accuracy for lateral meniscal tears was 72.7%, sensitivity 55% and specificity 87.5%. Accuracy and sensitivity for severity of ACL tear was 93.2% and of MCL tear 86.4%. In 88.6% of the knees, bone bruises were visible, with anterolateral femoral and posterolateral tibial bone bruise being the most common. MRI revealed no chondral lesion, but arthroscopy revealed 11. In combined ACL-MCL ruptures, the incidence of concomitant injuries is high and the injuries are best detected with MRI.

Bone bruises associated with ACL rupture: correlation with injury mechanism

BACKGROUND

Different patterns of bone bruising are seen on magnetic resonance imaging in acute anterior cruciate ligament ruptures. These patterns may relate to the mechanism of injury.

HYPOTHESIS

There is a correlation between the mechanism of anterior cruciate ligament injury and bone bruise patterns on magnetic resonance imaging.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Data regarding the mechanism of anterior cruciate ligament rupture were collected prospectively on patients who had anterior cruciate ligament reconstructions. Inclusion criteria included a clear history of mechanism, magnetic resonance imaging within 6 weeks of injury, and no previous knee injury. Patients were divided into noncontact and contact mechanism groups. Bone bruise frequency, location, depth, and intensity were analyzed using magnetic resonance imaging and correlated with the mechanism of injury.

RESULTS

Two hundred fifty-six patients were identified; 100 met the inclusion criteria, 86 were in the noncontact mechanism group, and 14 were in the contact mechanism group. The proportion of bone bruises in the lateral compartment in both groups was higher (P < .001) than in the medial compartment. Bone bruising was more frequent, deeper, and more intense in the noncontact group, with frequency (P = .019) and intensity (P < .001) scores reaching significance at the lateral tibial plateau. Medial compartment bone bruising was seen more frequently than previously reported, particularly in the noncontact group.

CONCLUSION

The noncontact mechanism appears to cause more severe bone bruising in both the medial and lateral compartments.

MR imaging of acute anterior cruciate ligament injuries

MRI of the knee has become an indispensable clinical tool in the management of chronic knee conditions. MRI for acute knee injuries is less well established but is becoming increasingly prevalent. MRI in acute ACL injuries is particularly useful for identifying associated injuries that will influence the early management of the patient. The aim of this paper is to describe the MRI findings of acute ACL tears, their commonly associated, and less common but serious associated injuries. Where available, the evidence for the sensitivity and specificity of these MRI features is presented. The contribution of these MRI findings to the management of the patient is discussed.

The incidence of anterior cruciate ligament injuries among competitive Alpine skiers: a 25-year investigation

BACKGROUND

Little is known about the evolution of anterior cruciate ligament injury rates among elite alpine skiers.

PURPOSE

To evaluate epidemiologic aspects of anterior cruciate ligament injuries among competitive alpine skiers during the last 25 years.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

Data were collected from elite French national teams (379 athletes: 188 women and 191 men) from 1980 to 2005.

RESULTS

Fifty-three of the female skiers (28.2%) and 52 of the male skiers (27.2%) sustained at least 1 anterior cruciate ligament injury. The overall anterior cruciate ligament injury incidence was 8.5 per 100 skier-seasons. The primary anterior cruciate ligament injury rate was 5.7 per 100 skier-seasons. The prevalence of reinjury (same knee) was 19%. The prevalence of a bilateral injury (injury of the other knee) was 30.5%. At least 1 additional anterior cruciate ligament surgery (mean, 2.4 procedures) was required for 39% of the injured athletes. Men and women were similar with regard to primary anterior cruciate ligament injury rate (P = .21), career remaining after the injury (P = .44), and skiing specialty (P = .5). There were more anterior cruciate ligament injuries (primary, bilateral, re-injuries) among athletes ranking in the world Top 30 (P < .001). Anterior cruciate ligament-injured athletes had a career length of 7.5 years, whereas athletes with no anterior cruciate ligament injury had a career of 4.5 years (P < .001). Finally, injury rates remained constant over time.

CONCLUSION

Anterior cruciate ligament injury rates (primary injury, bilateral injury, reinjury) among national competitive alpine skiers are high and have not declined in the last 25 years. Finding a way to prevent anterior cruciate ligament injury in this population is a very important goal.

Does ACL reconstruction restore knee stability in combined lesions?: An in vivo study

Treating anterior cruciate ligament (ACL) lesions combined with a torn medial collateral ligament (MCL) is controversial because residual laxity may lead to stretching of the ACL graft and eventual failure of the reconstruction. Few studies describe the in vivo translations of combined ACL and MCL injuries. We compared the preoperative and postoperative laxity between patients with combined ACL+MCL Grade II injuries and isolated ACL ruptures and tested whether an ACL reconstruction could restore all laxities in both groups. We evaluated knee kinematics during ACL reconstruction in 57 patients (37 ACL lesions and 20 ACL+MCL injury). Laxity tests were performed before and after graft fixation. Postoperatively, there was greater anteroposterior laxity and greater varus-valgus laxity in the group with MCL injury compared to the group with an ACL lesion only. This finding suggests residual laxities remain when ACL reconstruction is performed in patients with combined ACL+MCL lesion, and raises the question of addressing the MCL ligament when Grade II laxity is found.

Meniscus-stabilizing function of the meniscofemoral ligament: experimental study of pig knee joints

PURPOSE

To demonstrate experimentally, with the use of pig knee joints, that the posterior meniscofemoral ligament (PML) stabilizes the lateral meniscus (LM).

METHODS

Amputated stumps of the knee joints of Yorkshire pigs, which are anatomically similar to human knee joints, were used. The PML was intact or was cut according to 1 of 6 different conditions: (1) intact PML with intact LM, (2) intact PML with a radial tear of the posterior horn of the LM, (3) intact PML with total lateral meniscectomy, (4) cut PML with intact LM, (5) cut PML with a radial tear of the posterior horn of the LM, and (6) cut PML with total lateral meniscectomy. Pressure-sensitive film was inserted beneath the lateral femoral condyle, an axial load of 150 kg was placed on the knee joint with a universal testing machine, and the pressed area and maximum and average pressures were measured with the Prescale Imaging Analysis System (Fujifilm Medical Systems, Stamford, CT).

RESULTS

With an intact PML, no difference was seen between the intact meniscus and the radial tear of the posterior horn of the LM in pressed area and maximum and average pressures. With a cut PML, pressure concentration, detected as significantly reduced pressed area and increased maximum and average pressures, was observed, regardless of the condition of the LM.

CONCLUSIONS

PML of the pig stabilized the LM under an axial load, and an intact PML yielded results similar to those observed in total lateral meniscectomy. Our findings suggest that posterior horn tears of the LM, which are rarely symptomatic, may be caused by stabilizing of the lateral meniscus by the PML against the load placed on the knee joint.

CLINICAL RELEVANCE

Findings suggest that the PML, lateral side, stabilizes the LM when the ligament is intact. Even when a tear of the meniscus occurs, no increased localized pressure areas appear on the meniscus; this may explain why these tears are rarely symptomatic.

Epidemiology of athletic knee injuries: A 10-year study

The knee is an anatomically and biomechanically complex joint. Few studies have been published reporting the type and frequency of knee injuries. However, this information that may help to prevent, diagnose, and treat knee joint injuries. We have documented 17,397 patients with 19,530 sport injuries over a 10-year period of time. 6434 patients (37%) had 7769 injuries (39.8%) related to the knee joint. 68.1% of those patients were men and 31.6% were women. Almost 50% of the patients were between the ages of 20-29 (43.1%) at the time of injury. The injuries documented were ACL lesion (20.3%), medial meniscus lesion (10.8%), lateral meniscus lesion (3.7%), MCL lesion (7.9%), LCL lesion (1.1%), and PCL lesion (0.65%). The activities leading to most injuries were soccer (35%) and skiing (26%). LCL injury was associated with tennis and gymnastics, MCL with judo and skiing, ACL with handball and volleyball, PCL with handball, lateral meniscus with gymnastics and dancing, and medial meniscus with tennis and jogging.

Meniskus- und Bandläsionen

The knee is one of the major weight-bearing joints and is relatively exposed to trauma. Capsuloligamentous structures are essential to provide joint stability and -- in turn -- persistent instability bears a risk for osteoarthritis that needs timely and comprehensive diagnosis. Using MRI it may be beneficial to routinely apply (T)SE sequences in all three major planes as a basic protocol and to add additional sequences according to the clinical information available and imaging findings in the basic protocol. Especially fat-suppressed sequences (STIR, T2w/PDw FS TSE) are very useful because they sensitively depict bone marrow edema pattern (BMEP)-like changes. This finding often alerts the reader to -- sometimes only discrete -- underlying pathologies and may -- if found in typical locations -- give information about the mechanism of injury and thus lead the radiologist to look for specific concomitant capsuloligamentous, cartilage, and/or meniscal injury. BMEP is quite prominent in contusion injury, whereas often it is but discrete in avulsion lesions. There is extensive literature about the signs, possible pitfalls, and the accuracy of MRI for the diagnosis of specific pathologies such as meniscal tears or cruciate or collateral ligament ruptures. However, combined injuries of more than one structure are frequent and affect the therapeutic approach. Thus, the primary goal of the radiologist is to go beyond the description of any isolated lesion and to give a comprehensive description of (or to reliably exclude) any injury to other structures. A necessary prerequisite to accomplish this is a thorough knowledge of the -- in some locations -- complex anatomic relationships, pitfalls, and locations where lesions typically occur and where they may be overlooked.

Intra-articular findings in the reconstructed multiligament-injured knee

PURPOSE

Intra-articular chondral and meniscal injury in the multiligament-injured knee has not been examined. The purpose of this study was to determine the pattern of intra-articular chondral and meniscal damage in subjects with multiligament knee injuries undergoing surgery.

TYPE OF STUDY

Prospective cohort study.

METHODS

Analysis was performed on prospectively collected data for the presence of meniscal tears and significant chondral injury on subjects who underwent knee ligament surgery. Subjects were grouped by their multiligament injury combination. Chondral injury was graded using the Modified Outerbridge Classification system. Criteria for significant chondral defect were any grade 2 lesion involving 50% or more of condylar width and all grade 3 or 4 lesions. Groups with more than 10 subjects were compared against the anterior cruciate ligament (ACL)-only group.

RESULTS

Data were collected on 2,265 subjects. The ACL/medial collateral ligament (MCL) injury pattern was the most common multiligament injury, comprising 70.5% of all multiligament injuries. Lateral meniscal damage was significantly higher in the ACL/MCL group (P < .01). Medial meniscal damage was significantly lower in the ACL/MCL group (P < .01). Medial and lateral meniscal damage was significantly lower in the ACL/lateral collateral ligament (LCL) group (P < .01). Articular damage to the medial tibial plateau was significantly lower in the ACL/MCL group (P < .01). All other multiligament injury patterns showed chondral damage similar to the ACL-only group. Ligament injuries repaired acutely had significantly less articular and medial meniscal damage than chronic repairs (P < .01).

CONCLUSIONS

The ACL/MCL injury pattern was the most common multiligament injury pattern and showed a high incidence of lateral meniscal tears. ACL/LCL injuries had fewer meniscal injuries. Multiligament-injured knees showed increased risk of a torn medial meniscus as chronicity increased.

LEVEL OF EVIDENCE

Level IV.

Nonoperative treatment of partial-thickness meniscal tears identified during anterior cruciate ligament reconstruction

The reported incidence and treatment of partial-thickness meniscal tears seen at anterior cruciate ligament (ACL) reconstruction varies widely. The success of nonoperative treatment of partial meniscal tears identified during ACL reconstruction at our institution was reviewed. All incomplete meniscal tears were treated with observation, all full-thickness tears were treated with repair or partial meniscectomy. Partial tears of the lateral meniscus were noted three times more commonly than in the medial meniscus and were seen more acutely after ACL injury than full-thickness tears. At 2-year follow-up, excellent knee function was noted when these tears were treated nonoperatively.

A review of ski injuries resulting in combined injury to the anterior cruciate ligament and medial collateral ligaments

Alpine skiing is a global winter recreational sport with 15 million participants in the United States alone, and an overall injury rate of 2.5 per 1,000 ski person-days. Isolated injury to the anterior cruciate ligament (ACL) or the medial collateral ligament (MCL) is common among ski injuries; however, combined injury to these structures is rare. Controversy in the management of ACL instability following alpine ski injury is diminishing with improvements in the techniques of intra-articular cruciate reconstruction. However, the management of the combined ACL-MCL injury remains something of an enigma. Evidence exists to support both surgical and nonsurgical management strategies for the medial structures, but little consensus exists for the timing of the repair. This paper highlights the mechanisms of ski injuries that can result in combined injury to the ACL and MCL. The anatomy and biomechanics of the medial complex as it relates both to stability and operative repair are reviewed, and literature on the techniques and indications used for MCL repair in the setting of a combined injury is presented. On the basis of this review, we believe that an injury to the MCL does not need to be repaired if the ACL is reconstructed after a combined injury.

Meniscal injury: I. Basic science and evaluation

The patient with meniscal injury may present with pain, swelling, or mechanical symptoms and often requires surgical intervention for symptom resolution. Treatment of such injuries relies on understanding the gross and microanatomic features of the meniscus that are important in maintaining meniscal function. The ability of the meniscus to participate in load bearing, shock absorption, joint lubrication, and joint stability depends on the maintenance of its structural integrity. The diagnosis of meniscal injury often can be made by clinical evaluation utilizing the history, physical examination, and plain radiographs. Magnetic resonance imaging can be useful in confirming the diagnosis when clinical findings are inconclusive. Treatment depends on tear pattern, vascularity, and an assessment of tissue quality. Surgical decision making for the treatment of meniscal injury is based on patient factors and understanding of the meniscal structure, function, and pathology.

Magnetic resonance imaging of the knee

Magnetic resonance imaging (MRI) has revolutionised diagnostic imaging of the knee. It has evolved significantly since Kean described healthy and pathologic knee anatomy in 1983. This innovative technology allows superior soft-tissue detail with multiplanar imaging capability that provides accurate evaluation of intra- and extra-articular structures of the knee not demonstrated with other imaging modalities. The development and advancements in MRI and the introduction of high-resolution coils have provided a noninvasive, nonoperator dependent, cost effective means to diagnose knee pathology. MRI is well tolerated by patients, widely accepted by evaluating physicians, and assists in distinguishing pathologic knee conditions that may have similar clinical signs and symptoms (i.e. meniscal tears, osteochondral lesions). This paper presents an overview of MRI of the knee and focuses on the MRI findings in a number of common pathologic conditions.