Partial versus complete acute anterior cruciate ligament tears. The results of nonoperative treatment

A study was undertaken to determine whether a significantly different clinical outcome could be expected following nonoperative treatment of acute partial anterior cruciate ligament (ACL) tears from that of complete tears. A detailed follow-up of 107 patients with arthroscopically confirmed tears was obtained; 72 were complete tears and 35 partial. The overall results in those with partial tears were 23% excellent, 29% good, 17% fair, and 31% poor; with complete tears the results were 11% excellent, 20% good, 15% fair, and 54% poor. The patients with partial tears had a lower incidence of associated meniscal tears, needed fewer reconstructions and more of them returned to sport than those with complete tears.     

Primary knee ligament repair--revisited

There were 4710 knee sprains resulting from skiing in the four Aspen ski areas between 1976 and 1979. Twenty percent of the patients (942) had complete tears. Of these, 302 elected to remain in Aspen for treatment. All were treated by primary ligament repair without augmentation. These cases were evaluated an average of 42 months after injury. Patients with isolated tears of the medial collateral ligament were found to be doing well; virtually all of them had returned to preinjury activity levels. Thirty-six percent of the isolated anterior cruciate repairs were rated failures, and 43% of the combination ACL-MCL injuries had failed because of anterior cruciate deficiency. Twenty-nine percent of the ACL and ACL-MCL injuries had meniscal tears. Cases that included meniscectomy had a failure rate twice as great as those in which the meniscus was preserved. The results following repair of anterior cruciate tears were not acceptable, and augmentation was indicated. Primary repair of medial collateral ligament tears produced excellent results. Meniscal tears were frequent in association with ligament disruption. Ligament repairs were less satisfactory when meniscectomy was performed at the time of the repair.     

Partial tears of the anterior cruciate ligament: diagnosis and treatment

In sports medicine, diagnosis and treatment of partial tears of the anterior cruciate ligament (ACL) continue to be difficult. Partial tears of the ACL are common, representing 10% to 28% of all ACL tears. As our understanding of the anatomy of the native ACL improves, our accuracy in diagnosing these injuries increases. The advent of magnetic resonance imaging (MRI) and recognition of injury patterns have more clearly delineated the pathoanatomy in a majority of these cases. Natural history studies following patients with these injuries have demonstrated that fewer than 50% of patients return to their preinjury activity level. Several studies have also documented that progression to complete rupture is a common outcome for patients who want to return to an active lifestyle. Treatment options include conservative modalities (eg, activity modification, functional rehabilitation, functional bracing) and surgery (eg, thermal shrinkage of remaining ACL, complete reconstruction, newer techniques to augment or reconstruct the damaged portion of the native ligament). Studies comparing conservative treatments with more aggressive operative interventions are required to fully evaluate the efficacy of these treatments.     

Accuracy of nonorthogonal magnetic resonance imaging in acute disruption of the anterior cruciate ligament

A controlled, prospective study of 30 patients with suspected acute internal derangement of the knee was undertaken to evaluate the sensitivity, specificity, predictive value, and accuracy of nonorthogonal (oblique) sagittal magnetic resonance imaging (MRI) in the assessment of anterior cruciate ligament (ACL) injuries. Thirty patients with acute hemarthroses underwent MRI within 12 days of injury, followed by arthroscopy within 24 h of the MRI. A control population of 30 chondromalacia patients underwent similar evaluation. In the acute hemarthrosis patient population, the incidence at arthroscopy of acute complete ACL tears was 60% (18/30); of partial ACL tears, 13.3% (4/30); and of chronic tears, 10% (3/30). A normal ACL was found in 16.6% (5/30) of patients. In the MRI evaluation of patients with suspected ACL injury the following results were obtained for both acute and chronic complete disruption on orthogonal (sagittal) and nonorthogonal (oblique sagittal) imaging, respectively: sensitivity, 61 (16/26) versus 100%; specificity, 70 (21/34) versus 100%; positive predictive value, 61 (16/26) versus 100%; negative predictive value 70 (24/34) versus 100%; and accuracy, 66 (40/60) versus 100%. In the evaluation of partial ACL injury, four partial tears were correctly diagnosed on nonorthogonal MRI, with one false-positive diagnosis. Orthogonal imaging failed to correctly identify any of the partial ACL injuries. Two patients in the control population demonstrated evidence of chronic ACL tears. We believe that we have demonstrated the superiority of T2-weighted nonorthogonal sagittal over conventional orthogonal sagittal ACL MRI in the evaluation of ACL injury.     

陈旧性前交叉韧带损伤诊治分析

[目的]探讨临床检查和MRI诊断陈旧性前交叉韧带（anterior cruciate ligament，ACL）损伤的价值。[方法]回顾分析65例陈旧性ACL损伤患者的诊治经过，进行临床检查，其中8例行MRI检查，最后关节镜手术确诊。[结果]53例ACL完全损伤，前抽屉试验、Lachman试验和轴移试验的准确性分别为：79．2％、96．2％和92．5％；12例ACL部分损伤，前抽屉试验、Lachman试验和轴移试验的准确性分别为：16．7％、50．0％和33．3％。MRI诊断ACL损伤的准确性为100％。[结论]临床检查和MRI是诊断陈旧性ACL损伤的有效方法。     

Does partial anterior cruciate ligament rupture really exist?

From 1983 to 1989 129 partial tears of the anterior cruciate ligament were diagnosed by arthroscopy. To confirm the diagnosis of a partial rupture of the anterior cruciate ligament, we began to split the synovial sheath of the anterior cruciate ligament in 1986 in order to prove the continuity of the fibers. Applying this technique, we quite often found the anterior cruciate ligament completely torn. Hence the rate of partial tears of the anterior cruciate ligament decreased from about 10% of all anterior cruciate ligament ruptures 1983 to about 3% 1989. 42 patients whose diagnosis had been a partial rupture of the anterior cruciate ligament were reviewed clinically to determine whether the anterior cruciate ligament injury had finally proved to be an insignificant lesion or had caused a knee instability. The overall results were very good in 12% and good in 14%; 41% showed a fair, 26% a poor result. Because of this unfavourable outcome, we believe that most of the partial tears of the anterior cruciate ligament should be regarded as complete ruptures.     

The contribution of each anterior cruciate ligament bundle to the Lachman test: a cadaver investigation

The clinical diagnosis of a partial tear of the anterior cruciate ligament (ACL) is still subject to debate. Little is known about the contribution of each ACL bundle during the Lachman test. We investigated this using six fresh-frozen cadaveric lower limbs. Screws were placed in the femora and tibiae as fixed landmarks for digitisation of the bone positions. The femur was secured horizontally in a clamp. A metal hook was screwed to the tibial tubercle and used to apply a load of 150?N directed anteroposteriorly to the tibia to simulate the Lachman test. The knees then received constant axial compression and 3D knee kinematic data were collected by digitising the screw head positions in 30° flexion under each test condition. Measurements of tibial translation and rotation were made, first with the ACL intact, then after sequential cutting of the ACL bundles, and finally after complete division of the ACL. Two-way analysis of variance analysis was performed. During the Lachman test, in all knees and in all test conditions, lateral tibial translation exceeded that on the medial side. With an intact ACL, both anterior and lateral tibial landmarks translated significantly more than those on the medial side (p < 0.001). With sequential division of the ACL bundles, selective cutting of the posterolateral bundle (PLB) did not increase translation of any landmark compared with when the ACL remained intact. Cutting the anteromedial bundle (AMB) resulted in an increased anterior translation of all landmarks. Compared to the intact ACL, when the ACL was fully transected a significant increase in anterior translation of all landmarks occurred (p < 0.001). However, anterior tibial translation was almost identical after AMB or complete ACL division. We found that the AMB confers its most significant contribution to tibial translation during the Lachman test, whereas the PLB has a negligible effect on anterior translation. Section of the PLB had a greater effect on increasing the internal rotation of the tibia than the AMB. However, its contribution of a mean of 2.8° amplitude remains low. The clinical relevance of our investigation suggests that, based on anterior tibial translation only, one cannot distinguish between a full ACL and an isolated AMB tear. Isolated PLB tears cannot be detected solely by the Lachman test, as this bundle probably contributes more resistance to the pivot shift.     

Partial tears of anterior cruciate ligament: Results of single bundle augmentation

Background:

Partial tears of the anterior cruciate ligament (ACL) are common and usually present with symptomatic instability. The remnant fibers are usually removed and a traditional ACL reconstruction is done. But with increased understanding of ACL double bundle anatomy, the remnant tissue preservation along with a single bundle augmentation of the torn bundle is also suggested. The purpose of this study was to evaluate the results of selective anatomic augmentation of symptomatic partial ACL tears. Our hypothesis is that this selective augmentation of partial ACL tears could restore knee stability and function.

Materials and Methods:

Consecutive cases of 314 ACL reconstructions, 40 patients had intact ACL fibers in the location corresponding to the anteromedial (AM) or posterolateral (PL) bundle and were diagnosed as partial ACL tears perioperatively. All patients underwent selective augmentation of the torn bundle, while keeping the remaining fibers intact using autogenous hamstring graft. A total of 38 patients (28 males, 10 females) were available with a minimum of 3 years followup. 26 cases had AM bundle tears and 12 cases had PL bundle tears respectively. Patients were assessed with International Knee Documentation Committee (IKDC) 2000 Knee Evaluation Form, Lysholm score; instrumented knee testing was performed with the arthrometer (KT 2000). Statistical analysis was performed to compare the preoperative and postoperative objective evaluation.

Results:

At 3 years followup, 31.6% patients were graded A, 65.8% were graded B and 2.6% was graded C at IKDC objective evaluation. Manual laxity tests, Lysholm''s score, mean side to side instrumental laxity and Tegner activity score improved significantly. 76% patients returned to preinjury level of sports activity after augmentation.

Conclusion:

The results of anatomic single bundle augmentation in partial ACL tears are encouraging with excellent improvement in functional scores, side to side laxity and return to sports activity.     

The outcome of nonoperatively treated complete tears of the anterior cruciate ligament in active young adults

The results of nonoperative treatment of 72 patients with complete anterior cruciate ligament (ACL) tears, documented by examination under anesthesia and arthroscopy, were evaluated. All patients had an acute injury with hemarthrosis in a previously normal knee. Patients having meniscal repair were excluded as were those with collateral or posterior cruciate ligament tears or associated fractures. Treatment in all cases consisted of a standard protocol of early rehabilitation and bracing. A detailed rating of symptoms and function was performed at an average of 38 months postinjury (range, eight to 84 months). Overall results were 11% excellent, 20% good, 15% fair, and 54% poor. Thirty-five percent had ACL reconstruction during the follow-up period. Results indicate that young adults who return to a vocation requiring strenuous physical activity frequently can expect unsatisfactory results after nonoperative treatment of an acute complete tear of the ACL.     

Complete tear of the lateral meniscus posterior root is associated with meniscal extrusion in anterior cruciate ligament deficient knees

This study aimed to evaluate the relationship between preoperative lateral meniscal extrusion (LME) and arthroscopic findings of lateral meniscus posterior root tear (LMPRT) in knees with anterior cruciate ligament (ACL) tear. Thirty‐five knees that had LMPRTs with concomitant ACL tears on arthroscopy were evaluated. Patients were divided into two groups, partial and complete root tears, via arthroscopic findings at the time of ACL reconstruction. For comparison, we added two groups, using the same database; 20 normal knees (normal group) and 20 ACL‐injured knees without LM injury (intact LM group). We retrospectively measured preoperative LMEs using magnetic resonance imaging (MRI). Twenty‐three knees had partial LMPRTs. Complete LMPRTs were observed in 12 knees. The average LME was ?0.1 ± 0.4 mm in the normal group, 0.2 ± 0.5 mm in the intact LM group, 0.4 ± 0.8 mm in the partial LMPRT group, and 2.0 ± 0.6 mm in the complete LMPRT group. A significant difference in preoperative LMEs was observed between the complete LMPRT group and the other groups (p < 0.001). The receiver operating curve analysis, which distinguishes a partial tear from a complete tear, identified an optimal cut‐off point of 1.1 mm for preoperative LME. This LME cut‐off had a sensitivity of 100% and specificity of 83% for complete LMPRT. We found that preoperative LMEs were larger in complete LMPRTs associated with ACL injuries than in partial LMPRTs. Our results suggest that preoperative MRI‐detected LME may be a useful indicator for estimating LMPRT severity in ACL‐injured knees. Level of evidence: Retrospective comparative study level IV. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1894–1900, 2018.

     

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.     

Vascular physiology and long-term healing of partial ligament tears.

Functional outcomes of anterior cruciate ligament (ACL) injury are generally poorer than those of medial collateral ligament (MCL) tears. Following ligament damage, all phases of ligament healing require an adequate blood supply. We hypothesized that the differences in healing properties of the ACL and MCL would reflect their vascular responses to joint injury. This paper examines the long-term changes in blood flow and vascular volume of rabbit knee ligaments after direct injury, and under conditions of chronic joint instability induced by section of the posterior cruciate ligament (PCL). Standardized injuries were surgically induced in adult rabbit knee ligaments: partial MCL transection, partial ACL transection, or complete PCL transection (joint instability). Sixteen weeks later the blood flow and vascular volume of the ACL and MCL were measured and compared to control and sham-operated animals. Direct ligament injury induced significant increases in standardized blood flow and vascular volume of both ACL and MCL after 16 weeks; however, the vascular volume of the ACL was not higher than the control levels in the MCL. We conclude that direct injury to both the anterior cruciate and MCLs induces long-term physiological responses. Joint laxity is a common sequel to PCL injury. Chronic joint laxity failed to induce adaptive vascular responses in the ACL, while the MCL shows significant amplification of blood supply. Although both MCL and ACL showed increased weight after PCL transection, the lack of a long-term vascular response in the ACL may be a major factor in its the diminished healing potential.     

Knee dislocation following anterior cruciate ligament disruption without any other ligament tears.

We report a rare case of complete knee dislocation following anterior cruciate ligament (ACL) disruption without any other ligament tears. The pathology of the knee joint was torn ACL, intact other ligaments, osteochondral fractures and bone bruise of the lateral femoral condyle, and torn lateral meniscus. In this case, osteochondral fracture resulting from the anteriorly sublaxiation of the tibia following ACL disruption was considered to prevent from spontaneous reduction. This case suggests that anterolateral knee dislocation and spontaneous reduction may occur in ACL injuries.     

Knee function following suture of fresh tear of the anterior cruciate ligament

A retrospective consecutive series of 60 patients treated with primary suture of knee ligament injuries is presented. All patients had an anterior ligament (ACL) tear. In 54 patients this injury was combined with a medial compartment tear. Four patients had isolated tears of the ACL. At follow-up after 4 years, 11 patients complained of instability, and in eight of these an anterolateral rotatory instability was demonstrated by the Slocum test. In contrast, only five of 49 patients with subjectively stable knees had positive Slocum tests. Thirty of 47 patients with negative Slocum tests had excellent function, compared with four of 13 patients with positive tests.     

Chronic anterior cruciate ligament deficiency is associated with increased anterior translation of the tibia during the transition from non-weightbearing to weightbearing.

Translation of the tibia relative to the femur was measured while a group of subjects with normal knees and group with anterior cruciate ligament (ACL) tears underwent transition from non-weightbearing to weightbearing stance. Subjects were positioned in the Vermont knee laxity device (VKLD) with muscles relaxed and the limb segment and compressive joint load offset (non-weightbearing). A lateral radiograph of the knee, with the posterior aspects of the femoral condyles superimposed, was obtained to document the position of the tibia relative to the femur. Immediately after, a compressive load equal to 40% of bodyweight was applied to each foot, and a second radiograph was obtained to document the change in position of the tibia relative to the femur. The transition from non-weightbearing to weightbearing produced a significant increase of anterior translation of the tibia relative to the femur (mean; 3.4 mm) for the subjects with ACL tears compared with the contralateral normal knees (0.8 mm). Similarly, there was a significant increase in anterior translation of the tibia for the subjects with ACL tears compared to the group of subjects with normal knees (1.2 mm). The fourfold increase in anterior translation of the tibia for the knees with ACL tears compared to the contralateral side is a concern because it is substantially greater than the 95% confidence limits of the side-to-side differences in anterior-posterior knee laxity measured from subjects with normal knees. This observation could explain, at least in part, one of the mechanisms that initiates damage to the meniscus and articular cartilage in subjects that have suffered an ACL tear.     

Arthroscopically assisted combined anterior and posterior cruciate ligament reconstruction

This article presents the minimum 2-year results (range, 24 to 48 months) of 20 arthroscopically assisted combined anterior cruciate ligament/posterior cruciate ligament (ACL/PCL) reconstructions, evaluated preoperatively and postoperatively using the Tegner, Lysholm, and Hospital for Special Surgery knee ligament rating scales, and the KT 1000 knee ligament arthrometer (Medmetric Corp, San Diego, CA). There were 16 men or boys, 4 women or girls; 9 right, 11 left; 10 acute, and 10 chronic knee injuries. Ligament injuries included 1 ACL/PCL tear, 2 ACL/PCL/medial collateral ligament (MCL)/posterior lateral corner tears, 7 ACL/PCL/MCL tears, and 10 ACL/PCL/posterior lateral corner tears. ACLs were reconstructed using autograft or allograft patellar tendons. PCLs were reconstructed using allograft Achilles tendon, or autograft patellar tendon. MCL tears were successfully treated with bracing. Posterior lateral instability was successfully treated with long head of the biceps femoris tendon tenodesis. Teguer, Lysholm, and Hospital for Special Surgery knee ligament rating scales significantly improved preoperatively to postoperatively (P = .0001). Corrected anterior KT 1000 measurements improved from preoperative to postoperative status (P = .0078).     

Combined anterior cruciate ligament and medial collateral ligament injuries in adolescents

Although literature supports bracing of most medial collateral ligament (MCL) injuries followed by arthroscopic repair of anterior cruciate ligament (ACL) tears in adults with combined ACL-MCL injuries, little is published regarding the treatment of these injuries in the pediatric population. The purpose of this study was to present our outcomes after treatment of combined ACL-MCL injuries in a series of adolescents. All 180 patients who underwent ACL reconstruction at our children's hospital from January 1997 to January 2003 were reviewed to identify those patients with concomitant grade II or III MCL injuries. Clinical data were obtained from chart review. All patients were treated with a hinged brace for their MCL injury followed by delayed arthroscopic reconstruction of their ACL using a transphyseal technique with Achilles tendon soft tissue allograft. Patients were contacted by phone to complete Lysholm knee questionnaires and assess return to athletic competition. Data were compared with a control cohort of patients who underwent isolated ACL reconstruction using the same technique. Twelve (6.7%) of 180 patients had combined ACL-MCL injuries. There were 6 boys and 6 girls; the mean age was 15.6 years (range, 14-17 years). Follow-up averaged 5.3 years (range, 2.6-8.2 years), and no patients were lost to follow-up. At last examination, all patients had a stable knee on both Lachman and valgus stress tests; the mean Lysholm knee score was 96 (range, 94-100). All patients were able to return to their preinjury level of athletics. One patient required manipulation for arthrofibrosis. When compared with the control group of 19 isolated ACL reconstructions, there was no significant difference with regards to Lysholm scores or return to athletics.Bracing of grade 2 or 3 MCL injuries followed by ACL reconstruction was an effective means of treating combined ACL-MCL injuries in this small series of adolescent patients.     

Objective anterior cruciate ligament testing

We examined subjects with the Stryker knee laxity tester as part of the clinical examination to determine its usefulness in evaluating the anterior cruciate ligament. We measured 123 athletes with no history of knee injury, as well as 30 patients with ACL injury proven by arthroscopy, and 11 injured patients with intact ACL at arthroscopy. We recorded anterior and posterior tibial displacement at 20 degrees of knee flexion and 20 lbs force in each direction. Anterior laxity and side to side difference correlated with ACL injury; posterior and total AP laxity did not. In normal subjects, mean anterior laxity was 2.5 mm. Only 8% of normal knees had anterior laxity of 5 mm or more. Ten percent of normal subjects had a side to side difference of 2 mm or more. In ACL tears, mean laxity was 8.1 mm, with 94% measuring 5 mm or more. Of the subjects, 89% with unilateral ACL injury had an increase of 2 mm or more on the injured side. Ten of ten acute ACL tears were detected by these criteria, with no false positives. In injured knees with intact ACL, measurements did not differ significantly from normal. We found the objective knee laxity measurement to be a useful complement to clinical knee examination.     

A comparison of accuracy between clinical examination and magnetic resonance imaging in the diagnosis of meniscal and anterior cruciate ligament tears

A prospective and retrospective study was undertaken to compare the accuracy of magnetic resonance imaging (MRI) with clinical examination in diagnosing meniscal and anterior cruciate ligament (ACL) tears. Pathological findings were then confirmed during arthroscopy. One hundred fifty-four patients clinically diagnosed with a meniscal or ACL tear who ultimately had arthroscopic knee surgery were evaluated; 100 patients underwent clinical examination followed by MRI, and 54 underwent clinical examination alone. The presence or absence of meniscal and ACL tears was confirmed during arthroscopy. The accuracies of clinical examination and MRI were compared for the 100 patients who underwent both clinical examination and MRI. The accuracy of MRI was 75% for medial meniscal tears, 69% for lateral meniscal tears and 98% for ACL tears. The accuracy of clinical examination was 82% for medial meniscal tears, 76% for lateral meniscal tears and 99% for complete tears of the ACL. Furthermore, the accuracy of clinical examination for the 54 patients who underwent clinical examination alone was not significantly different from the accuracy of clinical examination in the 100 patients who also underwent MRI. There was no significant difference between the accuracy of clinical examination and MRI in the diagnosis of meniscal and ACL tears and, overall, MRI contributed to treatment in only 16 of 100 cases. Based on these findings, we feel that MRI, except in certain circumstances, is an expensive and unnecessary diagnostic test in patients with suspected meniscal and ACL pathology.     

Anterior cruciate ligament injury in children and adolescents

Although the natural history of anterior cruciate ligament (ACL) injuries in the adult is well documented, the natural history of ACL injury in children and adolescents has not previously been reported. A case note review revealed 31 cases with ACL pathology out of 212 arthroscopies performed in the Adelaide Children's Hospital from November 1980 until June 1986. Partial tears were more common than complete midsubstance tears. In 27 cases there was no bony involvement. All 27 patients were available for analysis. The average age was 14.3 years, with a range of 8-18 years. Twelve of the 27 patients were younger than 14 years old. All patients completed a questionnaire and were interviewed. The average follow-up was 51 months (range 26-87 months). At the time of initial injury, 11 of the 27 patients (41%) had associated pathology. Subsequently, four patients have undergone further arthroscopic surgery, four patients have had a reconstruction of the ACL, and a further three have had reconstruction recommended. We conclude that this is not as benign an injury as was previously believed.