MRI as an accurate tool for the diagnosis and characterization of different knee joint meniscal injuries

Background

The knee menisci are compound anatomical structures with important purposes within the knee. In the long term, meniscal losing results in high risk of developing degenerative osteoarthritis. MRI is an accurate and non-invasive diagnostic method for the knee injuries providing satisfactory guide for conservative treatment and guarding the patients from uncritical arthroscopy.

The value of multi-detector CT arthrography of the wrist joint in evaluation of ligamentous and capsular injuries in post-traumatic pain

The wrist joint is a complex joint containing several intrinsic and extrinsic ligaments that contribute to carpal stability. There is increased incidence of ligamentous/capsular injury following trauma.

A systematic review and meta-analysis of the diagnostic accuracy of MRI for suspected ACL and meniscal tears of the knee

Purpose

To determine the diagnostic accuracy of magnetic resonance imaging (MRI) and ultrasound (US) in the diagnosis of anterior cruciate ligament (ACL), medial meniscus and lateral meniscus tears in people with suspected ACL and/or meniscal tears.

Methods

MEDLINE, Web of Science and the Cochrane library were searched from inception to March 2014. All prospective studies of the diagnostic accuracy of MRI or US against arthroscopy as the reference standard were included in the systematic review. Studies with a retrospective design and those with evidence of verification bias were excluded. Methodological quality of included studies was assessed using the QUADAS-2 tool. A meta-analysis of studies evaluating MRI to calculate the pooled sensitivity and specificity for each target condition was performed using a bivariate model with random effects. Sub-group and sensitivity analysis were used to examine the effect of methodological and other study variables.

Results

There were 14 studies included in the meta-analysis of the accuracy of MRI for ACL tears, 19 studies included for medial meniscal tears and 19 studies for lateral meniscal tears. The summary estimates of sensitivity and specificity of MRI were 87 % (95 % CI 77–94 %) and 93 % (95 % CI 91–96 %), respectively, for ACL tears; 89 % (95 % CI 83–94 %) and 88 % (95 % CI 82–93 %), respectively, for medial meniscal tears; and 78 % (95 % CI 66–87 %) and 95 % (95 % CI 91–97 %), respectively, for lateral meniscal tears. Magnetic field strength had no significant effect on accuracy. Most studies had a high or unclear risk of bias. There were an insufficient number of studies that evaluated US to perform a meta-analysis.

Conclusion

This study provides a systematic review and meta-analysis of diagnostic accuracy studies of MRI and applies strict exclusion criteria in relation to the risk of verification bias. The risk of bias in most studies is high or unclear in relation to the reference standard. Concerns regarding the applicability of patient selection are also present in most studies.

Level of evidence

III.

     

Anterolateral ligament abnormalities in patients with acute anterior cruciate ligament rupture are associated with lateral meniscal and osseous injuries

Objective

To determine the frequency of anterolateral ligament (ALL) injury in patients with acute anterior cruciate ligament (ACL) rupture and to analyse its associated injury patterns.

Methods

Ninety patients with acute ACL rupture for which MRI was obtained within 8 weeks after the initial trauma were retrospectively identified. Two radiologists assessed the status of the ALL on MRI by consensus. The presence or absence of an ALL abnormality was compared with the existence of medial and lateral meniscal tears diagnosed during arthroscopy. Associated collateral ligament and osseous injuries were documented with MRI.

Results

Forty-one of 90 knees (46 %) demonstrated ALL abnormalities on MRI. Of 49 knees with intact ALL, 15 (31 %) had a torn lateral meniscus as compared to 25 torn lateral menisci in 41 knees (61 %) with abnormal ALL (p?=?0.008). Collateral ligament (p?≤?0.05) and osseous injuries (p?=?0.0037) were more frequent and severe in ALL-injured as compared with ALL-intact knees.

Conclusion

ALL injuries are fairly common in patients with acute ACL rupture and are statistically significantly associated with lateral meniscal, collateral ligament and osseous injuries.

Key Points

? ALL injuries are fairly common in patients with acute ACL rupture. ? ALL injuries are highly associated with lateral meniscal and osseous injuries. ? MRI assessment of ACL-injured knees should include evaluation of the ALL.

     

Anterolateral ligament injuries in knees with an anterior cruciate ligament tear: Contribution of ultrasonography and MRI

Objectives

To describe the pathological appearance of the anterolateral ligament (ALL) on US and MRI in knees with an anterior cruciate ligament (ACL) tear.

Methods

This prospective study included 30 patients who had a suspected acute ACL tear. Their injured and contralateral knees were evaluated with radiography, US and MRI. Two radiologists evaluated the ALL on the MRI and US examinations. Agreement between these examiners’ findings was evaluated with Cohen’s kappa.

Results

On US examination, the ALL was found to be injured in 63% of cases (19/30; k = 0.93). The enthesis was found to be torn in 50% of cases (15/30; k = 1), with the tear located at the tibial attachment in all instances. On the MRI exam, the ALL was found to be injured in 53% of cases (16/30; k = 0.93). The enthesis was found to be torn in 13% of cases (4/30; k = 0.76), with the tear located at the tibial attachment in all instances (k = 0.93).

Conclusion

ALL injuries that occur with ACL tears are located at the tibial enthesis. They are often associated with bone avulsion at the enthesis and are better viewed on US.

Key Points

? ALL injuries often occur in combination with ACL tears. ? ALL injuries can be assessed with ultrasonography and MRI. ? ALL injuries associated with ACL tears are located at the tibial enthesis.

     

Meniscus repair with simultaneous ACL reconstruction demonstrated similar clinical outcomes as isolated ACL repair: a result not seen with meniscus resection

Purpose

To compare Knee Injury and Osteoarthritis Outcome Score (KOOS) and EuroQol-5D (EQ-5D) subscale scores at 2-year follow-up for patients with primary isolated ACL reconstruction with patients undergoing ACL reconstruction and simultaneous meniscal treatment in terms of either resection or repair in the Swedish National Knee Ligament Register (SNKLR).

Methods

All ACL reconstruction patients within the SNKLR at 2-year follow-up were reviewed. The KOOS and EQ-5D subscales were assessed in four distinct patient groups: isolated ACL reconstruction, ACL reconstruction?+?medial meniscus resection, ACL reconstruction?+?lateral meniscus resection, ACL reconstruction?+?medial meniscus repair, and ACL reconstruction?+?lateral meniscus repair. The primary analysis was conducted using linear regression with isolated ACL reconstruction designated as the reference group, and was adjusted for patient age, gender, and time from injury to surgery.

Results

The included patients consisted of 10,001 (65.0%) individuals with an isolated ACL injury, 588 (3.8%) with ACL injury plus treated with medial meniscus repair, 2307 (15.0%) with ACL injury plus treated with medial meniscus resection, 323 (2.1%) with ACL injury plus treated with lateral meniscus repair, and 2173 (14.1%) with ACL injury plus treated with lateral meniscus resection. Meniscus resection demonstrated significantly worse results with respect to the KOOS Symptoms subscale for both the medial and lateral meniscus resection groups. Medial meniscus resection also demonstrated worse results for the KOOS quality of life (QoL) subscale, while lateral meniscus resection only approached significance. Outcomes were not different between the isolated ACL reconstruction group and the meniscus repair groups.

Conclusion

Meniscus resection in addition to ACL reconstruction resulted in worse clinical outcomes than isolated ACL reconstruction patients; a result not seen within the meniscus repair group. This suggests that, when possible, meniscus repair may provide greater clinical outcomes over resection when treating a reparable meniscal tear that presents along with an ACL tear. Clinicians should consider and implement these findings for the management of future meniscus tear patients within their clinical practice.

Level of evidence

Level III.

     

MR imaging of anterior cruciate ligament reconstruction poor outcomes

Purpose

Is to study the diagnostic value of MR imaging in assessment of poor outcomes of ACL reconstruction using second look arthroscopy of the knee as a gold standard.

Patients and methods

51 patients were included in this study who did ACL reconstruction followed by MRI and second look arthroscopy. Arthroscopy study was performed within 7–15 days from MR examination. The time interval between ACL reconstruction and MRI examination was 10 months to 9 years. MR images were evaluated for; (1) ACL graft failure assessing the primary and secondary signs, (2) Tibial and femoral tunnel location, and (3) Complication of ACL graft reconstruction. MR imaging results were compared with the arthroscopic results.

Results

Second look arthroscopy revealed 23 patients with full- thickness ACL graft tears, 17 partial -thickness ACL graft tears and 11 intact ACL grafts. Complete ACL graft discontinuity, focal ACL graft thinning and preserved 100% graft thickness were the most valuable primary MRI signs in the diagnosis of full thickness ACL graft tear, partial tear and intact graft respectively.

Conclusion

We found MR imaging to be reliable for the evaluation of ACL graft poor outcomes including graft failure and complications.     

Reliability of magnetic resonance imaging in evaluating meniscal and cartilage injuries in anterior cruciate ligament-deficient knees

Purpose

The accuracy of magnetic resonance (MR) imaging in assessing meniscal and cartilage injuries in anterior cruciate ligament (ACL)-deficient knees as compared to arthroscopy was evaluated in the present study.

Methods

The results of all preoperative MR imaging performed within 3 months prior to the ACL reconstruction were compared against intraoperative arthroscopic findings. A total of 206 patients were identified. The location and type of meniscal injuries as well as the location and grade of the cartilage injuries were studied. The negative predictive value, positive predictive value, sensitivity, specificity and accuracy of MR imaging for these 206 cases were calculated and analysed.

Results

In patients with an ACL injury, the highest incidence of concomitant injury was that of medial meniscus tears, 124 (60.2 %), followed by lateral meniscus tears, 105 (51.0 %), and cartilage injuries, 66 (32.0 %). Twenty-three (11.2 %) patients sustained injuries to all of the previously named structures. MR imaging was most accurate in detecting medial meniscus tears (85.9 %). MR imaging for medial meniscus tears also had the highest sensitivity (88.0 %) and positive predictive value (88.7 %), while MR imaging for cartilage injuries had the largest specificity (84.1 %) and negative predictive value (87.1 %). It was least accurate in evaluating lateral meniscus tears (74.3 %). The diagnostic accuracy of medial meniscus imaging is significantly influenced by age and the presence of lateral meniscus tears, while the duration between MR imaging and surgery has greater impact on the likelihood of lateral meniscus and cartilage injuries actually being present during surgery. The majority of meniscus tears missed by MR imaging affected the posterior horn and were complex in nature. Cartilage injuries affecting the medial femoral condyle or medial patella facet were also often missed by MR imaging.

Conclusion

MR imaging remains a reliable tool for assessing meniscus tears and cartilage defects preoperatively. It is most accurate when evaluating medial meniscus tears. However, MR imaging should be used with discretion especially if there is a high index of suspicion of lateral meniscus tears.

Level of evidence

IV.

     

Association of specific meniscal pathologies and other structural pathologies with self-reported mechanical symptoms: A cross-sectional study of 566 patients undergoing meniscal surgery

Objectives

We explored associations between specific meniscal pathologies and other concurrent structural knee pathologies with presence of self-reported mechanical symptoms in patients undergoing meniscal surgery.

Influence of lateral meniscal posterior root avulsions and the meniscofemoral ligaments on tibiofemoral contact mechanics

Purpose

The purpose of this study was to investigate the effect of lateral meniscal posterior root avulsions combined with intact meniscofemoral ligaments (MFLs), deficient MFLs, anterior cruciate ligament (ACL) tears and reconstructions, and root repairs using an established tibiofemoral contact mechanics testing protocol.

Methods

Ten fresh-frozen cadaveric knees were tested with six knee conditions (1: intact; 2: lateral meniscal posterior root avulsion; 3: root avulsion and deficient MFLs; 4: condition 3 with ACL tear; 5: condition 4 with ACL reconstruction; 6: ACL reconstruction with root repair) at five flexion angles (0°, 30°, 45°, 60°, and 90°), under a 1000-N axial load. Contact area and pressure were measured with Tekscan sensors.

Results

Compared to the intact state, condition 2 did not significantly change lateral compartment contact area or pressure. Changes in contact mechanics were greater at increased flexion angles; for condition 3 at 0° and 90°, contact area decreased 37 and 52 % [95 % CI (21–53) and (39–66), respectively] and mean contact pressure increased 55 and 87 % [95 % CI (33–76) and (59–114), respectively]. Root repair with ACL reconstruction was not significantly different from the intact state.

Conclusions

The MFLs protect the lateral compartment from changes in contact mechanics in the setting of a lateral meniscal posterior root avulsion, whereas a combination of lateral meniscal root avulsion and deficient MFLs leads to significant changes. Concurrent ACL reconstruction and lateral meniscal root repair restore mean contact pressure and area to the intact state and are recommended in this combined injury to prevent or slow the development of lateral compartment arthritis.

     

The role of magnetic resonance imaging (MRI) in assessment of ACL graft failure

Objective

The aim of this work is to assess the role of MRI in the diagnosis of ACL graft failure and detection of complications that may follow ACL reconstruction.

Discoid lateral meniscus can be overlooked by magnetic resonance imaging in patients with meniscal tears

Purpose

MRI evaluation of torn lateral meniscus was compared with arthroscopy. This study calculates the sensitivity, specificity, and accuracy of MRI in determining the presence or absence of discoid lateral meniscus (DLM) for different tear types.

Methods

MR imaging of 156 knees with arthroscopically confirmed lateral meniscus tears was analysed. There were 78 knees (70 patients) in non-DLM group and 78 knees (74 patients) in DLM group on arthroscopy as the reference standard. The presence of DLM on MRI was determined by an orthopaedic surgeon and a radiologist, who were blinded to the arthroscopic findings. The presence of discoid meniscus on MRI was determined by coronal and sagittal measurements, considering the tear pattern of lateral meniscus. The tear pattern was categorized into six types based on arthroscopic findings: horizontal, longitudinal, radial, combined radial, degenerative, and complex tear. The sensitivity, specificity, and accuracy of MRI were calculated for each type of lateral meniscus tear. In addition, we analysed the reason for non-detection of discoid meniscus on preoperative MRI.

Result

The sensitivity for determining the presence of discoid meniscus was 58% for radial tear, 57% for combined radial tear, and 65% for longitudinal tear, whereas the specificity was 100% for all tear groups. In the presence of radial or longitudinal tear, the accuracy of MRI was significantly lower than having no radial and longitudinal tear (p < 0.001). The presence of discoid meniscus was not recognized on MRI because of large radial tear (12 knees), deformed bucket-handle tear (6 knees), and inverted flap tear (3 knees).

Conclusions

MRI was not successful in determining the presence or absence of DLM in radial tear, combined radial tear, and longitudinal tear. When there are large radial tear, deformed bucket-handle tear, and inverted flap tear in lateral meniscus, it is recommended to consider the possibility of DLM. This information can help to make accurate diagnosis of DLM, which allows appropriate surgical planning and facilitates patient’s information on poor prognosis of DLM.

Level of evidence

Level I.

     

Lateral femoral notch depth is not associated with increased rotatory instability in ACL-injured knees: a quantitative pivot shift analysis

Purpose

A deep lateral femoral notch (LFN) on lateral radiographs is indicative of ACL injury. Prior studies have suggested that a deep LFN may also be a sign of persistent rotatory instability and a concomitant lateral meniscus tear. Therefore, the purpose of this study was to evaluate the relationship between LFN depth and both quantitative measures of rotatory knee instability and the incidence of lateral meniscus tears. It was hypothesized that greater LFN depth would be correlated with increased rotatory instability, quantified by lateral compartment translation and tibial acceleration during a quantitative pivot shift test, and incidence of lateral meniscus tears.

Methods

ACL-injured patients enrolled in a prospective ACL registry from 2014 to 2016 were analyzed. To limit confounders, patients were only included if they had primary ACL tears, no concurrent ligamentous or bony injuries requiring operative treatment, and no previous knee injuries or surgeries to either knee. Eighty-four patients were included in the final analysis. A standardized quantitative pivot shift test was performed pre-operatively under anesthesia in both knees, and rotatory instability, specifically lateral compartment translation and tibial acceleration, was quantified using tablet image analysis software and accelerometer sensors. Standard lateral radiographs and sagittal magnetic resonance images (MRI) of the injured knee were evaluated for LFN depth.

Results

There were no significant correlations between LFN depth on either imaging modality and ipsilateral lateral compartment translation or tibial acceleration during a quantitative pivot shift test or side-to-side differences in these measurements. Patients with lateral meniscus tears were found to have significantly greater LFN depths than those without on conventional radiograph and MRI (1.0 vs. 0.6 mm, p?<?0.05; 1.2 vs. 0.8 mm, p?<?0.05, respectively).

Conclusion

There was no correlation between lateral femoral notch depth on conventional radiographs or MRI and quantitative measures of rotatory instability. Concomitant lateral meniscus injury was associated with significantly greater LFN depth. Based on these findings, LFN depth should not be used as an indicator of excessive rotatory instability, but may be an indicator of lateral meniscus injury in ACL-injured patients.

Level of evidence

Prognostic level IV.

     

Relevant traumatic injury of the knee joint-MRI follow-up after 7-10 years

Objective

To evaluate prospectively the history of relevant traumatic knee injuries at least 7 years after trauma by MRI focusing on the development of degenerative changes.

Materials and methods

Seventeen patients without baseline degenerative changes had a follow-up knee MRI several years after relevant knee injury (interval baseline—follow-up was 9.1 years, S.D. ±1.3 years). Relevant knee injury was defined as complete cruciate or collateral ligament rupture, traumatic meniscal tear or osteochondral injury. Baseline MRI examinations were evaluated for traumatic ligamentous, chondral, meniscal and osseous lesions. Follow-up MRIs were evaluated for ligamentous and meniscal status, articular surface and incidence of degenerative changes such as cartilage loss, osteophytes and bone marrow lesions.

Results

Among the 11 patients who had a complete rupture of the ACL at baseline, 3 (27.3%) presented with cartilage loss. Among the eight patients who had suffered a post-traumatic meniscal tear at baseline, four (50%) presented with cartilage loss at follow-up. Among the five patients who had an osteochondral fracture at baseline, two (40%) presented with cartilage loss at follow-up imaging. Cartilage loss in all cases was observed adjacent to the subregions where meniscal damage and/or osteochondral incongruence was/were present at follow-up imaging.

Conclusion

We hypothesize that the post-traumatic or postsurgical meniscal damage and the persistence of an irregular articular surface may have played a role in the subsequent loss of cartilage in our patient population.     

Meniscal repair results in inferior short-term outcomes compared with meniscal resection: a cohort study of 6398 patients with primary anterior cruciate ligament reconstruction

Purpose

To compare patient reported outcome measures (PROMs) during the first postoperative year between isolated anterior cruciate ligament (ACL) reconstruction and ACL reconstruction with concomitant meniscal intervention.

Methods

Patients who underwent primary ACL reconstruction at Capio Artro Clinic, Stockholm, Sweden, between 1st Jan 2001 and 31st Dec 2014 without concomitant injuries others than meniscal and/or cartilage lesions were included. Five groups of meniscal treatment simultaneously to ACL reconstruction were established; medial meniscal (MM) resection, MM repair, lateral meniscal (LM) resection, LM repair, and MM?+?LM resection. Patients treated with isolated ACL reconstruction formed a separate group. Preoperative, 6-month and 1-year Knee Injury and Osteoarthritis Outcome Score (KOOS), and Lysholm knee score and Tegner Activity scale were collected. Differences in the change over time were analyzed with an ANOVA for repeated measurements with age at surgery, gender, and cartilage injury as covariates. A univariate ANOVA was applied to analyze PROMs between groups at the final follow-up.

Results

A total of 6398 patients were included (56.8% males, mean age 28.5?±?10.2 years). The KOOS improved across all subscales for all treatment groups. The mean change over time differed significantly between groups for the subscales symptoms (p?=?0.017) and activities in daily living (ADL) (p?<?0.001). Symptoms was least improved in the MM repair group, while the MM?+?LM resection group showed the largest improvement. For the ADL subscale, the isolated ACL reconstruction group showed the least improvement and the MM?+?LM resection group showed the major improvement. At 1-year follow-up, a significant difference between the groups was found for the subscale symptoms (p?=?0.019), where the MM repair group reported the lowest score [mean 78.4 (95% CI 76.3–80.5)]. No significant differences were found between groups in change of the Lysholm score over time; however, at 6 months, the difference between groups was significant (p?=?0.006) with the meniscal repair groups reporting the lowest scores.

Conclusion

Patients with concomitant meniscal resection are able to reach the same subjective knee function as isolated ACL reconstructions as early as 6 months postoperatively. However, patients with meniscal repair may have slightly worse subjective knee function at both 6- and 12-month follow-up. These findings could help clinicians to set realistic short-term expectations for patients undergoing ACL reconstruction with simultaneous meniscal intervention.

Level of evidence

3.

     

Improvement in the medial meniscus posterior shift following anterior cruciate ligament reconstruction

Purpose

Anterior cruciate ligament (ACL) reconstruction can reduce the risk of developing osteoarthritic knees. The goals of ACL reconstruction are to restore knee stability and reduce post-traumatic meniscal tears and cartilage degradation. A chronic ACL insufficiency frequently results in medial meniscus (MM) injury at the posterior segment. How ACL reconstruction can reduce the deformation of the MM posterior segment remains unclear. In this study, we evaluated the form of the MM posterior segment and anterior tibial translation before and after ACL reconstruction using open magnetic resonance imaging (MRI).

Methods

Seventeen patients who underwent ACL reconstructions without MM injuries were included in this study. MM deformation was evaluated using open MRI before surgery and 3 months after surgery. We measured medial meniscal length (MML), medial meniscal height (MMH), medial meniscal posterior body width (MPBW), MM–femoral condyle contact width (M-FCW) and posterior tibiofemoral distance (PTFD) at knee flexion angles of 10° and 90°.

Results

There were no significant pre- and postoperative differences during a flexion angle of 10°. At a flexion angle of 90°, MML decreased from 43.7 ± 4.5 to 41.4 ± 4.5 mm (P < 0.001), MMH from 7.5 ± 1.4 to 6.9 ± 1.4 mm (P = 0.006), MPBW from 13.1 ± 2.0 to 12.2 ± 1.9 mm (P < 0.001) and M-FCW from 10.0 ± 1.5 to 8.5 ± 1.5 mm (P < 0.001) after ACL reconstruction. The PTFD increased from 2.1 ± 2.8 to 2.7 ± 2.4 mm after ACL reconstruction (P = 0.015).

Conclusions

ACL reconstruction affects the contact pattern between the MM posterior segment and medial femoral condyle and can reduce the deformation of the MM posterior segment in the knee-flexed position by reducing abnormal anterior tibial translation. It possibly prevents secondary injury to the MM posterior segment and cartilage that progresses to knee osteoarthritis.

Level of evidence

IV.

     

Concordance of US and MRI for diagnosis of ligamentous and tendinous injuries around the ankle

Purpose

To estimate the accuracy of ultrasonography in detection of tendinous and ligamentous injuries around the ankle in comparison to MRI.

MRI diagnosis of ACL bundle tears: value of oblique axial imaging

Objective

To investigate the diagnostic accuracy of oblique axial intermediate weighting MR imaging in detecting partial thickness anterior cruciate ligament (ACL) bundle tears.

Materials and methods

The study protocol was approved by the institutional ethics committee. Sixty-one subjects (43 male, 18 female; mean age 27.4 years; range 9 to 57 years) with clinically suspected ACL tear or meniscal tear between September 2009 and January 2011 were studied with MRI and arthroscopy. Detection of partial tear for the ACL as a whole and for each ACL bundle by protocol A (standard orthogonal sequences) and protocol B (standard orthogonal sequences plus oblique axial intermediate weighted imaging) was compared in a blinded fashion. Performance characteristics for protocol A and protocol B were compared using sensitivity, specificity, accuracy and ROC curves. A two-tailed p value of <0.05 indicated statistical significance.

Results

Fifteen (24.6%) normal, 15 (24.6%) partial and 31 complete tears were diagnosed by arthroscopy. Sensitivity, specificity and accuracy of protocol A for the diagnosis of partial tear of the ACL was 33%, 87% and 74%, while for protocol B the values were 87%, 87% and 87% respectively. The area under the curve (AUC) for the diagnosis of partial ACL tear and individual bundle tear was higher for protocol B, although this difference did not reach statistical significance (p?>?0.05).

Conclusion

The addition of oblique axial imaging to standard MR imaging improves diagnostic accuracy for detecting partial tears of the ACL as well as individual bundle tears of the ACL.     

Similar failure rate in immediate post-operative weight bearing versus protected weight bearing following meniscal repair on peripheral,vertical meniscal tears

Purpose and hypothesis

Post-operative weight bearing after meniscal repair is a point of debate among physicians. This study sought to evaluate whether patients adhering to an immediate WBAT rehabilitation programme have a higher failure rate compared to those adhering to a more traditional, protected, NWB status following meniscal repair. The null hypothesis was that there would be no difference in failure between the two groups.

Methods

A retrospective review of meniscal repair patients greater than 5 years from surgery was performed for patients receiving meniscal repair treatment. Patients were categorized by post-surgical weight-bearing status, either NWB or WBAT, and then analysed for failure of repair. Failure was defined as re-operation on the torn meniscus. The study controlled for variables including age at surgery, sex, height, weight, and BMI, classification of tear type, acuity of the tear, repair location (medial or lateral), repair location within the meniscus, repair technique, and concomitant procedures.

Results

Re-operations were performed in 61 of 157 patients [38.9%]. There was no difference between weight-bearing groups for failure of meniscus repair (n.s.). The tears were acute vertical tears located in the posterior horn and body. For the 61 patients with re-operation, the average time to re-operation was 2.2 years with 10 [16%] > 5 years from surgery, 17 [28%] 2–5 years from surgery, and 34 [56%] < 2 years from surgery. In isolated meniscal repair patients (n = 62), there was no difference between weight-bearing groups for rate of re-operation (n.s.).

Conclusion

Weight bearing as tolerated after meniscal repair for peripheral, vertical tears does not result in a higher failure rate than traditional, non-weight bearing over a five-year follow-up period. The clinical relevance is that, based on these data, it may be appropriate to allow weight bearing as tolerated following meniscal repair of peripheral, vertical tears.

Level of evidence

Retrospective cohort study, Level III.

     

The “Lever Sign”: a new clinical test for the diagnosis of anterior cruciate ligament rupture

Purpose

A new clinical test for the diagnosis of ACL rupture is described: the so-called “Lever Sign”. This prospective study on four groups of patients divided subjects on the basis of MRI findings (complete or partial ACL lesion) and the clinical phase of the injury (acute or chronic). The hypothesis was that this manual test would be diagnostic for both partial and complete tears of the ACL regardless of the elapsed time from injury.

Methods

A total of 400 patients were evaluated and divided into four, equal-sized groups based on time elapsed from injury and MRI findings: Group A (acute phase with positive MRI for complete ACL rupture), Group B (chronic phase with positive MRI for complete ACL rupture), Group C (acute phase with positive MRI for partial ACL rupture), and Group D (chronic phase with positive MRI for partial ACL rupture). Clinical assessment was performed with the Lachman test, the Anterior Drawer test, the Pivot Shift test, and the Lever Sign test. The Lever Sign test involves placing a fulcrum under the supine patient’s calf and applying a downward force to the quadriceps. Depending on whether the ACL is intact or not, the patient’s heel will either rise off of the examination table or remain down. Additionally, the Lever Sign test was performed on the un-injured leg of all 400 patients as a control.

Results

All tests were nearly 100 % sensitive for patients with chronic, complete tears of the ACL. However, for patients with acute, partial tears, the sensitivity was much lower for the Lachman test (0.42), Anterior Drawer test (0.29), and Pivot Shift test (0.11), but not the Lever Sign test (1.00).

Conclusion

In general, chronic, complete tears were most successfully diagnosed but acute, partial tears were least successfully diagnosed. The Lever Sign test is more sensitive to correctly diagnosing both acute and partial tears of the ACL compared with other common manual tests. The clinical relevance is that some ACL ruptures may be more accurately diagnosed.