Grading the pivot shift. Objective tests with implications for treatment

Reconstruction of the ACL with a semitendinosus tendon graft: a prospective randomized single blinded comparison of double-bundle versus single-bundle technique in male athletes

Anterior cruciate ligament (ACL) reconstruction in double-bundle technique is advocated to more closely restore the anatomy and function of the native ligament than conventional single-bundle technique. But up to now there are only a few clinical investigations comparing both techniques in a prospective manner. We hypothesized that double-bundle ACL reconstruction reveals superior clinical and subjective results compared to single-bundle technique in a high-demand collective. A total of 50 male patients (mean age 29.4 years) were prospectively randomized consecutively into one of the two reconstruction techniques. Group 1 (SB) underwent a 4-stranded single-bundle reconstruction with a ST graft in femoral position at 10:00 and 02:00 o'clock, respectively. In group 2 (DB), reconstruction was performed by using a 2-stranded ST graft with double-bundle, four tunnel technique. Before surgery and at a 2 year follow-up (range 23-25 months) patients were evaluated by the same blinded observer. There was no significant difference in the side-to-side anterior laxity-measurement with the KT-1000 between both groups. As evaluated by the pivot shift, no significant correlation could be noted (Fisher exact test P = 0.098) between rotational stability and any of the both reconstruction techniques. However, the anterior and rotational stability improved significantly at 2-year follow-up compared to preoperatively (P = 0.003) in both groups. The statistical analysis showed a significant increase for the IKDC (subjective, objective) and the Lysholm Score at final follow-up among each single technique, while we found no significant difference between the two reconstruction methods. On the basis of our investigation, we conclude that reconstruction of the ACL by a double-bundle ST graft with an extracortical anchorage can achieve excellent clinical results. But in contrast to our initial hypothesis, we could not quote any significant advantages by creating two independent bundles. Reconstruction of the anterior cruciate ligament in conventional single-bundle technique with a more horizontal femoral tunnel placement obtains comparable clinical results in the present high-demand collective.

Current concepts review: comprehensive physical examination for instability of the knee

A careful history and physical examination are the cornerstones of orthopaedic sports medicine. When evaluating a patient for ligamentous instability of the knee joint, an understanding of the contribution of anatomic structures to stability enhances a practitioner's ability to achieve an accurate clinical diagnosis. This article reviews the various types of knee instability and the associated anatomic structures. Ultimately, information must be obtained from multiple tests to reach the final diagnosis. We describe in detail the pathologic and biomechanical basis of the tests for both tibiofemoral and patellofemoral instability of the knee joint and provide recommendations for performance and interpretation of these physical examinations.

A meta-analysis examining clinical test utilities for assessing meniscal injury

Objective: To systematically review the most recent literature with meta-analysis to summarize the accuracy of clinical tests for assessing meniscal lesions of the knee.

Methods and measures: A computerized database search was performed to identify eligible articles. Identified articles were reviewed to determine eligibility and methodological quality. Sensitivity, specificity, likelihood ratios and diagnostic odd ratios were reproduced or recorded from each study. Meta-analysis was performed using the reported study sensitivity and specificity values.

Results: Three tests — joint line tenderness, McMurray's and Apley's — were compared in the meta-analysis. The methodological quality of the studies was found to have a significant effect on both the test sensitivities and specificities. Summary receiver operating characteristic (ROC) curves, sensitivity values, mean likelihood ratios and diagnostic odd ratios (DOR) uniformly show joint line tenderness (DOR = 10.98) to be the best `common' test, followed by McMurray's (DOR = 3.99) and Apley's (DOR = 2.2). Thessaly's test reported the strongest DOR of 227, but samples were smaller (n = 410), than those for joint line tenderness (n = 1354), McMurray's (n = 1232) and Apley's (n = 479).

Conclusion: Methodological quality varied from poor to fair among studies, affecting test performance. Future studies should, where possible, utilize larger samples of individuals without meniscal lesions to better estimate test specificity and thus more accurately identify optimal clinical tests.

In vivo measurement of the pivot-shift test in the anterior cruciate ligament-deficient knee using an electromagnetic device

BACKGROUND

The pivot-shift test is commonly used for assessing dynamic instability in anterior cruciate ligament-insufficient knees, which is related to subjective knee function, unlike static load-displacement measurement. Conventional measurements of 3-dimensional position displacement cannot assess such dynamic instability in vivo and produce comparable parameters. Not only 3-dimensional position displacement but also its 3-dimensional acceleration should be measured for quantitative evaluation of the pivot-shift test.

HYPOTHESIS

Knees with a positive pivot-shift test result have increased tibial anterior translation and acceleration of its subsequent posterior translation, and they are correlated with clinical grading.

STUDY DESIGN

Controlled laboratory study.

MATERIALS AND METHODS

Thirty patients with isolated anterior cruciate ligament injury were included. Pivot-shift tests were evaluated under anesthesia manually and experimentally using an electromagnetic knee 6 degrees of freedom measurement system. From 60 Hz of 6 degrees of freedom data, coupled tibial anterior translation was calculated, and acceleration of posterior translation was computed by secondary derivative.

RESULTS

All anterior cruciate ligament-deficient knees demonstrated a positive pivot-shift test result. The coupled tibial anterior translation was 7.7 and 15.6 mm in anterior cruciate ligament-intact and -deficient knees, respectively. The acceleration of posterior translation was -797 and -2001 mm/s(2), respectively. These differences were significant (P < .01). The coupled tibial anterior translation and acceleration of posterior translation in the anterior cruciate ligament-deficient knee were larger in correlation with clinical grading (P = .03 and P < .01, respectively).

CONCLUSION

The increase of tibial anterior translation and acceleration of subsequent posterior translation could be detected in knees with a positive pivot-shift result, and this increase was correlated to clinical grading.

CLINICAL RELEVANCE

These measurements can be used for quantified evaluation of dynamic instability demonstrated by the pivot-shift test.

Reliability and usefulness of a new in vivo measurement system of the pivot shift

Residual pivot shift after ACL reconstruction is a crucial factor related to poor clinical outcome. However, no method exists that is able to evaluate pivot shift quantitatively and noninvasively. We propose a new measurement system for the pivot shift test using an electromagnetic device and have evaluated its reliability and clinical usefulness. Posterior translation, lateral translation and maximum velocity during the reduction phase of pivot shift were calculated and used as parameters for evaluation. In measurement system analysis, discrepancies of motion between the bones and the sensors were minimal, while reproducibility in repeated measurement was acceptable. Next, clinical usefulness was evaluated by correlating the values obtained by kinematic measurement with the clinical grade. We found differences in each of the measured parameters among clinical grades. These data suggest the system is a valuable measurement tool for clinical evaluation of the pivot shift test.

Combined reconstruction of chronic posterior cruciate ligament and posterolateral corner deficiency

We report a retrospective analysis of the results of combined arthroscopically-assisted posterior cruciate ligament reconstruction and open reconstruction of the posterolateral corner in 19 patients with chronic (three or more months) symptomatic instability and pain in the knee.

All the operations were performed between 1996 and 2003 and all the patients were assessed pre- and post-operatively by physical examination and by applying three different ligament rating scores. All also had weight-bearing radiographs, MR scans and an examination under anaesthesia and arthroscopy pre-operatively. The posterior cruciate ligament reconstruction was performed using an arthroscopically-assisted single anterolateral bundle technique and the posterolateral corner structures were reconstructed using an open Larson type of tenodesis.

The mean follow up was 66.8 months (24 to 110). Pre-operatively, all the patients had a grade III posterior sag according to Clancy and demonstrated more than 20° of external rotation compared with the opposite normal knee on the Dial test. Post-operatively, seven patients (37%) had no residual posterior sag, 11 (58%) had a grade I posterior sag and one (5%) had a grade II posterior sag. In five patients (26%) there was persistent minimal posterolateral laxity. The Lysholm score improved from a mean of 41.2 (28 to 53) to 76.5 (57 to 100) (p = 0.0001) and the Tegner score from a mean of 2.6 (1 to 4) to 6.4 (4 to 9) (p = 0.0001).

We conclude that while a combined reconstruction of chronic posterior cruciate ligament and posterolateral corner instability improves the function of the knee, it does not restore complete stability.

Effect of the iliotibial band on knee biomechanics during a simulated pivot shift test

The purpose of this study was to evaluate the effect of the iliotibial band (ITB) on the kinematics of anterior cruciate ligament (ACL) intact and deficient knees and also on the in situ force in the ACL during a simulated pivot shift test. A combination of 10 N-m valgus and 5 N-m internal tibial torques was applied to 10 human cadaveric knees at 15 degrees, 30 degrees, 45 degrees, and 60 degrees of flexion using a robotic/universal force-moment sensor testing system. ITB forces of 0, 22, 44, and 88 N were also applied. An 88 N ITB force significantly decreased coupled anterior tibial translation of ACL deficient knees by 32%-45% at high flexion angles, but did not have a significant effect at low flexion angles. Further, an 88 N ITB force significantly decreased in situ forces in the ACL at all flexion angles by 23%-40%. These results indicate that during the pivot shift test, the ITB can improve tibial reduction at high flexion angles while not affecting subluxation at low flexion angles. Additionally, the action of the ITB as an ACL agonist suggests that its use as an ACL graft might hinder knee stability in response to rotatory load.

Gravity-assisted pivot-shift test for anterior cruciate ligament injury: a new procedure to detect anterolateral rotatory instability of the knee joint

The denominated gravity-assisted pivot-shift test was introduced as a new procedure to detect anterolateral rotatory instability of the knee joint. The patient lies in the supine position or slightly rotated onto the affected side. The affected knee flexed approximately 60 degrees and the ipsilateral hip flexed, abducted and externally rotated so that the plane of the knee motion runs parallel to the floor. The examiner instructs the patient to raise the affected leg off the examining table and to extend the affected knee gradually. If the lower leg is internally rotated suddenly, with the knee subluxated at an angle of approximately 20 degrees , followed by the reduction in flexion, this test is regarded as positive. This test was investigated on 51 anterior cruciate ligament (ACL) deficient knees, being positive in 30 knees (Group P) and negative in 21 (Group N) with the positive rate of 59%. There was no significant correlation between the result of this test and the clinical features, but Group N included relatively small number of females and recurrent injuries tended to occur more frequently in Group P. Thirty-six knees received ACL reconstruction subsequently. There was no statistically significant difference between the groups in the side-to-side difference in anterior knee laxity at one year postoperatively. However, three patients with the side-to side difference of more than 3 mm belonged to Group P. Relatively low positive rate in ACL deficient knees suggests that it may not be used as a diagnostic procedure for ACL injury. It is possibly used for the prediction of high risk patients for symptomatic giving-way and/or patients with poor prognosis after ACL reconstruction.

A quantitative analysis of valgus torque on the ACL: a human cadaveric study

The loads needed to elicit a positive pivot shift test in a knee with an anterior cruciate ligament (ACL) rupture have not been quantified. The coupled anterior tibial translation (ATT), coupled internal tibial rotation (ITR), and the in situ force in the ACL in response to a valgus torque, an inherent component of the pivot shift test, were measured in 10 human cadaveric knee specimens. Using a robotic/universal force-moment sensor testing system, valgus torques ranging from 0.0 to 10.0 Nm were applied in nine increments on the intact and ACL-deficient knee in flexion ranging from 0 degrees to 90 degrees. At 15 degrees of knee flexion, the coupled ATT and ITR were significantly increased in the ACL-deficient knee when compared to the intact knee. Coupled ATT increased a maximum of 291% (6.7 mm, p<0.05), while coupled ITR increased a maximum of 85% (5.1 degrees, p<0.05). At 30 degrees, the increases in coupled ATT and ITR were significant at valgus loads of 3.3 Nm and greater with a maximum increase in coupled ATT of 137% (6.3 mm, p<0.05) and a maximum increase in coupled ITR of 38% (3.6 degrees, p<0.05). At 45 degrees, coupled ATT increased significantly (maximum of 69%, 4.4 mm, p<0.05), but only at torques > or =6.7 Nm. The in situ force in the ACL was less than 20 N for all flexion angles when a torque between 3.3 and 5.0 Nm was applied. Low valgus torque elicited tibial subluxation in the ACL-deficient knee with low in situ ACL forces, similar to a positive pivot shift test. Thus, application of a valgus torque may be suitable to evaluate ACL-deficient and ACL-reconstructed knees, since subluxation can be achieved with minimal harm to the ACL graft. This work is important in understanding one load component needed for the pivot shift examination; further studies quantifying other load components are essential for better comprehension of the in vivo pivot shift examination.

Clinical examination of the knee following trauma: an evidence-based perspective

The knee is a common site of injury. The increasing number of clinical tests and greater understanding of the joints biomechanics, lead to difficulties in both the interpretation of the clinical examination and in the reliance that should be placed on specific signs or tests. This article helps review the present evidence surrounding examination of the knee. This will enable clarification of which tests are most appropriate to be applied for specific injuries, and how they should be interpreted by the clinician. The most accurate test currently is that for anterior cruciate ligament deficiency as described by Lachman. Other classically taught tests, such as that of McMurray for meniscal tears, have been demonstrated to be of poor sensitivity and specificity.

The effect of axial tibial torque on the function of the anterior cruciate ligament: a biomechanical study of a simulated pivot shift test

PURPOSE

Various techniques are used to produce the pivot shift phenomenon after anterior cruciate ligament (ACL) injury. In particular, the amount of applied axial tibial torque varies among examiners. Thus, the objective of this study was to determine the effect of the magnitude and direction of axial tibial torque in combination with valgus torque on the resulting knee kinematics during such a simulated pivot shift test.

TYPE OF STUDY

This was a biomechanical study that used cadaveric knees with the intact knee of the same specimen serving as a control.

METHODS

On 19 human cadaveric knees (age, 26 to 69 years), a constant 10-Nm valgus torque was applied at 15 degrees of knee flexion. Then, internal and external tibial torque was applied incrementally from 0 to 10 Nm and the resulting kinematics of the ACL-intact and ACL-deficient knee, as well as the in situ force in the ACL, were measured using a robotic/universal force-moment sensor testing system.

RESULTS

In response to isolated valgus torque, the coupled anterior tibial translation for the ACL-intact and ACL-deficient knee was 1.6 +/- 2.4 mm and 8.5 +/- 4.7 mm, respectively; therefore the difference between the ACL-intact and ACL-deficient knee was 6.9 +/- 3.4 mm. With an external tibial torque greater than 5 Nm, the tibia translated up to 4 mm posteriorly for both the ACL-intact and ACL-deficient knee. Whereas, internal tibial torque greater than 1.6 Nm caused a rapid increase in coupled anterior tibial translation up to 10.2 mm in the ACL-deficient knee, while causing only a gradual increase for the ACL-intact knee. With excessive internal torque of 10 Nm, the difference in coupled anterior tibial translation was only 4.4 +/- 2.2 mm, suggesting a decrease in the sensitivity of the test. Correspondingly, the in situ force in the ACL under 10 Nm valgus tibial torque was 43 +/- 17 N, and increased up to 87 +/- 32 N as a 10-Nm internal torque was added. By applying a 3.3-Nm external tibial torque in addition to the 10-Nm valgus torque, the in situ force decreased to 21 +/- 14 N.

CONCLUSIONS

This study showed that a minimal amount of internal torque in combination with valgus torque may be a suitable way to elicit a pivot shift from an ACL-deficient knee.

Ten-year prognosis of isolated and combined medial collateral ligament ruptures. A matched comparison in 40 patients using clinical and radiographic evaluations

In a matched-pair study of 40 patients, the prognoses of patients with acute isolated partial medial collateral ligament injuries and acute combined medial collateral and anterior cruciate ligament injuries were compared 10 years after initial treatment. All patients in the first group were treated nonoperatively. In the latter group, most medial collateral ligament injuries were total ruptures, which were thoroughly repaired; the torn anterior cruciate ligament was repaired with augmentation in half of the cases. At the follow-up evaluation, both patient groups had similarly high knee functions according to the Lysholm score and similar activity levels (recreational team sports). Knees with combined injuries had increased sagittal laxity at manual and instrumented assessment. Radiographic signs of knee osteoarthritis were present in half of the knees with combined injuries, but they were absent in knees with isolated injuries. The long-term functional prognosis was similarly good after isolated or combined medial collateral ligament injuries, but patients with combined ruptures had more reinjuries and repeat surgeries, increased sagittal laxity, and a higher incidence of radiographic osteoarthritis.

Braided polypropylene augmentation device in reconstructive surgery of the anterior cruciate ligament: long-term clinical performance of 594 patients and short-term arthroscopic results, failure analysis by scanning electron microscopy, and synovial histomorphology

Long-term clinical results and short-term arthroscopic and microscopic findings from two augmented reconstruction procedures for the ruptured anterior cruciate ligament are reported. The braided polypropylene ligament augmentation device (Kennedy model) was used with temporary double-end fixation in 279 patients to augment the attachment of the anterior cruciate ligament after acute proximal rupture and in 315 patients to augment a bone-tendon-bone autograft, mainly after chronic instability. Check arthroscopy was performed and the metal fixation hardware was removed after a mean of 11 months. Of the 569 patients evaluated, 101 partial or total breakages of the ligament augmentation device were found. Together with nine breakages detected late in the follow-up period, 110 (19.3%) failures were found. Most of these failures were accompanied by effusion that was immediately alleviated when the failed device was removed. No generalized synovitis was visible. Scanning electron microscopic analysis of 24 retrieved failed ligament augmentation devices showed fatigue to be the principal failure mode, together with local abrasion at the fracture. Synovial biopsies were taken during arthroscopy in 84 patients with and without ligament augmentation device-failure who had given informed consent, and histological evaluation revealed that in 21 patients, chronic but no acute synovial inflammation was found, and wear particles could be identified in foreign body cells in 17. Statistically, the presence of chronic synovitis was predicted neither by wear particles and foreign body cells nor by abrasion or fatigue failure of the ligament augmentation device. Irrespective of the failures, for which ligament augmentation device removal is recommended, in the final Orthopaedische Arbeitsgemeinschaft Knie evaluation (after a mean of 6.2 years), excellent and good clinical results were found in 83.6% of all 594 patients.

Stress radiographs of the patellofemoral joint

Patellar instability is usually diagnosed on the basis of the clinical presentation without radiographic confirmation. In the present report, we describe a new radiographic method to demonstrate patellar instability. Axial radiographs were made of the patellofemoral joint of ninety individuals (180 knees) and were then repeated while a medial or lateral force was applied to the patella. The applied force was kept constant with use of a specially designed instrument. The ninety individuals were divided into four groups on the basis of the clinical findings: normal, lateral instability, medial instability, and multidirectional instability. Stress radiographs differentiated the four groups and confirmed the clinical diagnosis in all patients who had unilateral symptoms. A four-millimeter increase in medial or lateral excursion of the patella excursion of the asymptomatic knee was significant (p < 0.0001). Stress radiographs offer a simple method for the measurement of force-displacement relationships in the patellofemoral joint and for the demonstration of patellofemoral instability.

Evaluation of knee ligament injuries with the IKDC form

Various scoring systems have been proposed to quantify the disability caused by knee ligament injuries and to evaluate the results of treatment. None of these systems has found worldwide acceptance, mainly because all scoring systems attribute numerical values to factors that are not quantifiable, and then the arbitrary scores are added together for parameters not comparable with each other. For these reasons a group of knee surgeons from Europe and America met in 1987 and founded the International Knee Documentation Committee (IKDC). A common terminology and an evaluation form was created. This form is the standard form for all publications on results of treatment of knee ligament injuries. It is a concise one-page form. It includes a documentation section, a qualification section and a evaluation section. For evaluation there are four problem areas (subjective assessment, symptoms, range of motion and ligament examination). These are supplemented with four additional areas that are only documented but not included in the evaluation (compartmental findings, donor site pathology, X-ray findings and functional tests). The form can be used pre- and post-operatively and at follow-up. It has been specified that in any publication the minimum follow-up time for short-term results should be 2 years, for medium-term results 5 years and for long-term results 10 years. The largest part of the sheet is the qualification section. It is called "qualification" section rather than "scoring" section because no scores are given. Each parameter is qualified as "normal", "nearly normal", "abnormal" or "severely abnormal". This qualification is less subjective and emotional than "very good", "good", "fair" and "poor".(ABSTRACT TRUNCATED AT 250 WORDS)

Quantitative stress radiography for diagnosis of anterior cruciate ligament deficiency. Comparison between manual and instrumental techniques and between methods with knee flexed at 20 degrees and at 90 degrees

A portable stress-applying device for stress radiography was developed for daily clinical use. Using this device, stress radiography for the diagnosis of the anterior cruciate ligament (ACL) deficiency was performed with the knee flexed at 20 degrees and at 90 degrees. A 100-N force was chosen as a standardized stress. The subjects were classified into four groups: the manually tested ACL-deficient group (32 knees), the manually tested control group (80 knees), the instrumentally tested ACL-deficient group (14 knees), and the instrumentally tested control group (34 knees). There was no statistical difference in the reliability (sensitivity, specificity, and accuracy) of stress radiography between the manual technique and the instrumental technique. When stress radiography with the knee flexed at 20 degrees and that at 90 degrees were compared, the former was more reliable than the latter. As the manual technique is compromised by a lack of standardization in applied force, a mechanical device is required in quantitative stress radiography. The reliability of stress radiography with the knee flexed at 20 degrees is considered high enough to warrant dispensing with further stress radiography with the knee flexed at 90 degrees for diagnosing ACL deficiency.

Physiopathology of the knee joint after distal iliotibial band transfer

In an experimental study of 14 cadaver knee joints, the pressure load on the joint surface after distal iliotibial band transfer was measured using Fuji Prescale foils. With an intact anterior cruciate ligament, increases of up to 153% for the average pressure load and of 225% for the total pressure in the lateral compartment were found in relation to the fixation point chosen. At point P3--slightly dorsal to the insertion of the lateral collateral ligament--the area loaded with maximum pressure increased to six-fold. Fixation at the transition of the lateral femoral condyle to the femoral shaft at the start of the linea aspera was associated with the least pressure increases in both the lateral and the medial compartments. Under all experimental conditions, lateral extra-articular stabilization with fixation at the insertion of the fibular collateral ligament was shown to be associated with significantly higher load increases. While a shift of pressure load to the dorsal third was seen in the lateral compartment, the mid-third remained the focus of the pressure load in the medial compartment. After transection of the anterior cruciate ligament and iliotibial band transfer at the "over-the-top" point, a significant shift of pressure towards the medial compartment was seen, while the lateral pressure load decreased. Medially, the area loaded with peak pressure remained constant, while the corresponding area in the lateral joint space showed a highly significant decrease to nearly one-third of normal. After additional bilateral meniscectomy this tendency was even more pronounced.(ABSTRACT TRUNCATED AT 250 WORDS)

An analysis of the pivot shift phenomenon. The knee motions and subluxations induced by different examiners

The description of the pivot shift test and its modifications is for the most part based on clinical observations. We wished to precisely determine the knee motions and medial-lateral tibiofemoral compartment subluxations that examiners induce in the knee joint to produce the pivot shift phenomenon. Eleven skilled knee surgeons performed the pivot shift test on an instrumented cadaveric lower limb. The anterior cruciate and superficial medial collateral ligaments (long fibers) of one limb were sectioned to produce an abnormal state. An instrumented spatial linkage allowed all six degrees of freedom motions to be measured. Before and after ligament sectioning we determined the limits of knee motion under defined loading conditions. The tibial and femoral bony landmarks were digitized to determine the positions of the medial and lateral tibial plateaus in reference to the femoral condyles during the pivot shift tests. Each examiner performed his pivot shift test. The analysis of the data showed that examiners typically induced a coupled anterior translation and internal tibial rotation to produce an anterior tibial subluxation, and a coupled posterior translation and external tibial rotation to induce the reduction event. The magnitude of anterior subluxation of each plateau depended upon the examiner's technique. The maximal anterior subluxation of the lateral tibial plateau varied from 14 to 19.8 mm (mean, 17.2 +/- 2.0 mm), whereas anterior subluxation of the medial tibial plateau ranged from 6 to 16.9 mm (mean, 11.2 +/- 3.3 mm).(ABSTRACT TRUNCATED AT 250 WORDS)

The diagnosis of knee motion limits, subluxations, and ligament injury

The clinical diagnosis of knee ligament injuries requires the clinician to: 1) estimate the abnormal motion limits that occur in one or more of the six degrees of freedom that comprise three-dimensional motion; 2) determine the abnormal position (subluxation) of the medial and lateral tibiofemoral compartments; and 3) precisely define the anatomical structures injured and degree of that injury. To determine the clinician's ability to perform these tasks, we evaluated 11 knee surgeons' clinical examination for knee instability. The positions and motions included were measured in right-left cadaveric knees by a three-dimensional instrumented spacial linkage. We compared the clinicians' estimate of knee motion limits and subluxations with the actual measured values. Before and after the clinicians' examination, the three-dimensional limits of knee motion were measured in the knees in the laboratory under defined loading conditions. Also, in one knee, the ACL and superficial medial collateral ligament were cut and the examiners, none of whom were informed of the sectioning, were asked to arrive at a diagnosis. The results for all of the clinical instability tests were similar. There was wide variability between examiners in the starting position of knee flexion and tibial rotation and in the amount of tibial translation and rotation induced. Although some examiners displaced the knee to the maximal displacement limits obtained in the laboratory, others did not, by a substantial margin. This suggests a wide variation in the loads applied by examiners to the knee joint during the tests.(ABSTRACT TRUNCATED AT 250 WORDS)

Assessing the limits of knee motion

Ten patients were examined clinically by 11 experienced knee surgeons and with three measurement devices (Genucom, Knee Signature System, and KT-1000). Nine of the 10 patients examined had sustained documented intraarticular ligament disruptions including eight ACL disruptions and five posterior cruciate ligament disruptions. The eight patients with ACL injuries had undergone reconstructive surgery. The clinical examination test sequence was performed as described by the International Knee Documentation Committee. Testing results were reported as estimated degrees of angulation or millimeters of displacement. Testing results were divided into two groups based on the index minus nonindex knee difference. Eighteen displacement tests were performed on each knee by each examiner. The index minus nonindex knee difference was greater than 3 mm in 16% of the tests. Only 1 of the 198 displacement tests performed on the subject who did not have a ligament disruption was recorded as an index minus nonindex difference greater than 3 mm. There was appreciable difference between measurements recorded by different examiners, particularly anterior/posterior measurements in patients who had sustained combined anterior and posterior cruciate ligament injuries. There is a need to rigorously evaluate limits of motion tests that are used to develop treatment plans and report the results of ligament surgery.

Manual laxity tests for anterior cruciate ligament injuries

The manual laxity examination is the primary means by which clinicians evaluate ACL injuries. This paper reviews the literature and identifies the following ACL laxity tests: anterior drawer test, Lachman test. MacIntosh test, jerk test, flexion rotation drawer test, Slocum test, and the Losee test. Test technique, grading, limitations, and reliability are discussed for each test. General limitations of manual laxity tests are also presented. A review of ACL anatomy and the biomechanics of the pivot shift sign are provided to facilitate an understanding of the underlying principles of ACL laxity tests. J Orthop Sports Phys Ther 1990;11(10):474-481.

The pivot shift phenomenon: results and description of a modified clinical test for anterior cruciate ligament insufficiency

Clinical evaluation of knee instability is often difficult to reproduce, and several different physical tests have become popular. In an attempt to elucidate reasons for variations in the degree of pivot shift phenomenon seen with the use of the various tests, we have prospectively evaluated a group of 37 patients with surgically documented ACL injuries, noting the effects of hip position and tibial rotation. The patients were examined under anesthesia, and the pivot shift was graded as 0 (absent, or negative), 0.5+ (trace), 1+, 2+, or 3+ (with locking). All knees were tested in hip abduction, neutral, and hip adduction, and with the tibia in external and internal rotation, so that six positions were evaluated. Hip position strongly correlated with the degree of pivot shift regardless of tibial rotation. Overall, abduction produced the greatest degree of pivot shift, followed by neutral and finally adduction. External tibial rotation increased the pivot shift score in abduction and neutral, but not in adduction. A grading system for the subject population showed that abduction/external rotation (ABDER) resulted in the highest pivot shift scores, and that adduction/external rotation (ADDER) and adduction/internal rotation (ADDIR) resulted in the lowest scores. Nine patients out of 20 with a 3+ pivot shift in ABDER were negative in ADDER. The pivot shift score was dampened at least one grade from ABDER to ADDER in 92% of the patients. We conclude that hip position and tibial rotation affect the degree of pivot shift phenomenon, and it is our impression that the iliotibial band plays a significant role in controlling the degree of pivot shift observed.(ABSTRACT TRUNCATED AT 250 WORDS)