Manual Pivot Shift Research Articles

Long term results after transepiphysal ACL reconstruction in children and adolescent

Aims and Objectives: The aim of our study was to review the long term clinical and radiological (MRI) outcomes of adult patients who underwent ACL reconstruction as children or adolescent with emphasize to the features of growth disturbance, angular deformity, meniscal and cartilage damage and revision rate Materials and Methods: We retrospectively evaluated patient who underwent ACL reconstruction in our clinic with arthroscopic transepiphyseal technique using hamstrings graft in childhood or adolescence between the years 1997 and 2009. A total of 43 Patients were assessed. 25 male and 18 female. The average age at time of surgery was 13,5 years (8 - 16 y.), at time of assessement 22,4 years (18 - 30 y.) . The mean follow up was 10 years (4 - 16 years).The physical development of the patients was assessed with the Lysholm score and the Cincinnati Knee score scale, their satisfaction was recorded on the basis of the IKDC subjective knee evaluation form and the Tegner activity score . Leg deformity or leg length discrepancy was evaluated clinically by the observers. The instrumented Lachman test using KT1000 and manual Pivot shift test was performed to assess knee stability. MRI was used to detect graft integrity, cartilage and meniscal damages. Results: No significant leg deformities or leg length discrepancy had been detected. The average Lysholm score was 91 points (83 - 100), the Cincinnati Knee Score was 90,4 (79 - 100) points on average . The mean IKDC score was 92 points (82 -100). The Tegner-Activity-Score changed from preop 6,8 (2-10) to post op 5,8 (2-9).2 Patient underwent revision ACL reconstruction due to rerupture (3 and 9 years post op). 2 Patients underwent meniscal surgery during follow up (1 resection and one refixation). KT1000 evaluation showed 67% excellent, 21% good and in 12% bad results. The MRI scan showed 42 intact grafts and one unverifiable graft. One patient with cartilage damage up to 3° (ICRS), 3 patients with meniscal degeneration up to grade 2. Each patient showed a free range of motion Conclusion: Our data underlines that transepiphyseal ACL reconstruction in children and adolescent with hamstrings is a save procedure leading to good long term results without causing angular deformity or growth disturbance

Preoperative knee laxity measurements predict the achievement of a patient-acceptable symptom state after ACL reconstruction: a prospective multicenter study

ObjectiveTo determine whether patient-related factors, concomitant injuries and preoperative knee laxity could predict a patient acceptable symptom state (PASS) in the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF) at 1 and 2 years follow-up after anterior cruciate ligament (ACL) reconstruction in a multicentre cohort.MethodsPatients between 14 and 50 years of age who underwent single-bundle ACL reconstruction with hamstring tendon autograft within 1 year from the index injury were eligible. Additionally, only patients who completed the IKDC-SKF questionnaire at 1 or 2 years of follow-ups were included. Preoperative knee laxity assessment of patients in the awake state was performed using rolimeter, the Lachman and the pivot-shift test. The pivot shift was graded according to the IKDC criteria and also quantified by the use of non-invasive technology for (1) lateral tibial translation and (2) tibial acceleration. The quantitative pivot shift (QPS) was examined in the awake state and under anaesthesia (EUA). Univariable logistic regression models were performed with achieving PASS in the IKDC as the dependent variable.ResultsA total of 86 patients had complete data on the IKDC-SKF score at 1-year follow-up, of which 67 patients (77.9%) achieved PASS (age 24.8±9.3 years, 43% females). Two-year data were available for 50 patients, of which 39 patients (78.9%) achieved PASS (age 23.9±9.2 years, 42.0% females). A low-grade manual pivot shift according to IKDC grading had increased odds of achieving PASS at 1 year (OR=2.96 (95% CI 1.01 to 8.66), P<0.05) compared with patients who displayed a high-grade pivot shift preoperatively. However, this was not confirmed by the preoperative QPS measures (awake: tibial translation; OR=0.99,(95% CI 0.72 to 1.35), (n.s.), acceleration; OR=1.04,(95% CI 0.68 to 1.59), (n.s.) EUA: tibial translation; OR=1.02 (95% CI 0.78 to 1.31), (n.s.), acceleration; OR=1.14 (95% CI 0.93 to 1.40), (n.s.)). None of the studied variables of patient characteristics, concomitant injuries or knee joint laxity predicted PASS at the 2-year follow-up.ConclusionAlmost four in every five patients were able to achieve PASS 1 and 2 years after anatomic single-bundle ACL reconstruction. The presence of preoperative low-grade pivot shift increased the odds of achieving an acceptable level of knee function 1 year after ACL reconstruction compared with high-grade pivot shift; however, QPS did not confirm achievement of PASS in this study.Level of evidenceLevel III, prospective cohort.

The impact of bone morphology on the outcome of the pivot shift test: a cohort study

BackgroundThe presence of a positive pivot shift after surgical repair of the ACL is considered an important indicator of a failed reconstruction. The ability to predict the result of a pivot shift test after an ACL reconstruction using variables that can be measured prior to surgery could provide an indication of which patients may be at-risk of a poor surgical outcome.The purpose of this study was to determine whether structural characteristics of the femur and tibia, measured using plain radiographs, were associated with the result of the pivot shift test in unilateral ACL reconstructed patients.MethodsSixteen patients who had undergone unilateral ACL reconstruction were divided into two groups based on the results of manual pivot shift testing: 1) Pivot group; and 2) No pivot group. All patients had standing true lateral radiographs of both knees. Structural measurements of the tibia and femur were made on both knees. In addition, two new variables were created to describe the tibiofemoral mismatch: 1) Femur Tibia Size Ratio (FTSR); and 2) Tibia to Posterior Femoral Condyle Ratio (TPFCR). These measures were compared within groups and between groups.ResultsNone of the individual structural characteristics were significantly different when compared between groups. No individual structural characteristics had a significant association with the presence of a positive pivot shift. When a between-group analysis was performed, both the FTSR (p < 0.03) and the TPFCR (p < 0.01) were significantly different between the Pivot group and the No Pivot group. A larger FTSR ratio, or a larger femur relative to the tibia, was associated with a positive pivot shift. A smaller TPFCR ratio, or a smaller tibial depth relative to the depth of the lateral posterior femoral condyle, was associated with a positive pivot shift.ConclusionsStructural characteristics in the lateral femoral condyle and lateral tibial plateau were found to be associated with the presence of a positive pivot shift. These characteristics could separate between patients in the Pivot group and the No Pivot group. Two indices, the FTSR and the TPFCR, provided better predictive value than individual characteristics in identifying patients with a knee that was structurally “at-risk” for developing a positive pivot shift.

Kinematics of ACL and anterolateral ligament. Part I: Combined lesion.

To quantify the influence of ALL lesions on static and dynamic laxity in ACL-deficient knee. The study was performed in 10 fresh-frozen knees. The joints were analysed in the following conditions: intact, ACL resection and ACL+ALL resection. Testing parameters were defined as: anterior displacement at 30° and 90° of flexion (AP30, AP90) applying a manual-maximum load; internal rotation at 30° and 90° of flexion (INT30, INT90) applying a 5Nm torque and internal rotation and acceleration during manual pivot-shift (PS) test. Kinematics was acquired by a navigation system; a testing rig and a torquemeter were used to control the limb position and the applied torque. Paired Student's t test was conducted to assess statistical difference, and significance was set at P<0.05. The ALL resection determined a significant increase in terms of internal rotation (INT30 P=0.02, INT90 P=0.03), while AP30 (P n.s) and AP90 (P n.s) were not affected. ALL resection produced a significant increase in terms of acceleration during PS test (P<0.01), but no significant change in PS internal rotation was observed. The ALL plays a significant role in controlling static internal rotation and acceleration during PS test. On the other hand, ALL resection did not produce any significant change in terms of anterior displacement. A trend was seen for the internal rotation during the pivot-shift test to increase after ALL resection was higher when compared to the intact and isolated ACL lesion states; however, the differences were not significant. The results highlight the clinical relevance of this structure that should be assessed before an ACL reconstruction in order to avoid residual laxity.

A mechanical pivot-shift device for continuously applying defined loads to cadaveric knees.

Current techniques to study the biomechanics of the pivot-shift utilize either static or poorly defined loading conditions. Here, a novel mechanical pivot-shift device that continuously applies well-defined loads to cadaveric knees is characterized and validated against the manual pivot-shift. Six fresh-frozen human lower limb specimens were potted at the femur, mounted on a hinged testing base, and fitted with the mechanical device. Five mechanical and manual pivot-shift tests were performed on each knee by two examiners before and after transecting the ACL. Three-dimensional kinematics (anterior and internal-rotary displacements, and posterior and external-rotary velocities) and kinetics (forces and moments applied to the tibia by the device) were recorded using an optical navigation system and 6-axis load cell. Analysis of variance and Bland-Altman statistics were used to gauge repeatability within knees, reproducibility between knees, agreement between the mechanical and manual test methods, and agreement between examiners. The forces and moments applied by the device were continuous and repeatable/reproducible to within 4/10% of maximum recorded values. Kinematic variables (excluding external-rotary velocity) were qualitatively and quantitatively similar to manual pivot-shift kinematics, and were more repeatable and reproducible. The presented device induces pivot-shift-like kinematics by applying highly repeatable three-dimensional loads to cadaver knees. It is based on a simple mechanical principle and designed using easily obtainable components. Consequently, the device enables orthopaedic biomechanists to easily and reliably quantify the effect of ACL injury and reconstruction on pivot-shift kinematics.

Knee stability, athletic performance and sport-specific tasks in non-professional soccer players after ACL reconstruction: comparing trans-tibial and antero-medial portal techniques.

a wrong position of bone tunnels, in particular on the femur, is one of the most frequent causes of a failed anterior cruciate ligament (ACL) reconstruction. Several studies demonstrated that drilling the femoral tunnel through the antero-medial portal (AMP) allows a more anatomical placement on the lateral femoral condyle and higher knee stability, compared to trans-tibial (TT) technique. The aim of this study was to retrospectively evaluate two groups of soccer players operated on for ACL reconstruction according to either one of these two techniques. two groups of non-professional soccer players operated on for a single bundle ACL reconstruction with hamstrings autograft using either a TT (20 patients) or an AMP (23 patients) technique were retrospectively evaluated with KT-1000 arthrometer, manual pivot shift test, isokinetic test, the incremental treadmill-running test, athletic and sport specific tasks, and knee scores (IKDC, Lysholm and KOOS). the AMP group showed better results at pivot shift test and KOOS, but lower flexion angles at single leg squat test. There were no differences in all the other considered outcomes. the better rotational stability of the knee achieved in AMP group did not lead to significantly better clinical and functional results in our patients. Case-control study.

The relationship of anterior and rotatory laxity between surgical navigation and clinical outcome after ACL reconstruction

Recently, a computer-assisted navigation system has been used for the quantitative evaluation not only of anterior-posterior (AP) laxity but also rotational laxity of the tibia intraoperatively. The purpose of this study was to investigate how intraoperative AP or rotational laxities measured by the navigation system could correlate with postoperative AP and rotational laxities of the patients. 125 patients who underwent primary isolated anatomical single- or double-bundle ACL reconstruction or augmentation using multistranded autologous hamstring tendons were included in the study after a minimum of 2-year follow-up. Clinically, absolute value and side-to-side difference (SSD) of AP translation of the tibia were measured by KT-2000 preoperatively and postoperatively. Intraoperative measurement of AP translation of the tibia and total range of tibial rotation of the ACL-injured knee were carried out using the computer-assisted navigation system. We have investigated the relationship between intraoperative measurements using the navigation system and AP laxity measurements using the KT-2000 knee arthrometer as well as rotational laxity measurements using the manual pivot shift test. There was a positive correlation between the SSD of preoperative AP translation of the tibia measured by KT-2000 arthrometer and the reduction in AP laxity following ACL reconstruction measured by the navigation system. However, we found no significant correlation between the reduction in AP laxity measured by the navigation system and the SSD of AP translation of the tibia measured by the KT-2000 arthrometer at final follow-up. Postoperatively, eight patients had a positive pivot shift test. Using the navigation system pre- and post-ACL reconstruction, these patients could not be identified by high absolute values for AP laxity nor rotational laxity. Although AP and rotational laxities vary largely among the patients, and AP and rotational stabilization are successfully achieved immediately after ACL reconstruction, intraoperative AP and rotational laxity measured by the navigation system did not influence the postoperative AP and rotational laxities after ACL reconstruction. III.

Transtibial Versus Anteromedial Portal Reaming in Anterior Cruciate Ligament Reconstruction: An Anatomic and Biomechanical Evaluation of Surgical Technique

The purpose of this study was to objectively evaluate the anatomic and biomechanical outcomes of anterior cruciate ligament (ACL) reconstruction with transtibial versus anteromedial portal drilling of the femoral tunnel. Ten human cadaveric knees (5 matched pairs) without ligament injury or pre-existing arthritis underwent ACL reconstruction by either a transtibial or anteromedial portal technique. A medial arthrotomy was created in all cases before reconstruction to determine the center of the native ACL tibial and femoral footprints. A 10-mm tibial tunnel directed toward the center of the tibial footprint was prepared in an identical fashion, starting at the anterior border of the medial collateral ligament in all cases. For transtibial femoral socket preparation (n = 5), a guidewire was placed as close to the center of the femoral footprint as possible. With anteromedial portal reconstruction (n = 5), the guidewire was positioned centrally in the femoral footprint and the tunnel drilled through the medial portal in hyperflexion. An identical graft was fixed and tensioned, and knee stability was assessed with the following standardized examinations: (1) anterior drawer, (2) Lachman, (3) maximal internal rotation at 30°, (4) manual pivot shift, and (5) instrumented pivot shift. Distance from the femoral guidewire to the center of the femoral footprint and dimensions of the tibial tunnel intra-articular aperture were measured for all specimens. Statistical analysis was completed with a repeated-measures analysis of variance and Tukey multiple comparisons test with P ≤ .05 defined as significant. The anteromedial portal ACL reconstruction controlled tibial translation significantly more than the transtibial reconstruction with anterior drawer, Lachman, and pivot-shift examinations of knee stability (P ≤ .05). Anteromedial portal ACL reconstruction restored the Lachman and anterior drawer examinations to those of the intact condition and constrained translation with the manual and instrumented pivot-shift examinations more than the native ACL (P ≤ .05). Despite optimal guidewire positioning, the transtibial technique resulted in a mean position 1.94 mm anterior and 3.26 mm superior to the center of the femoral footprint. The guidewire was positioned at the center of the femoral footprint through the anteromedial portal in all cases. The tibial tunnel intra-articular aperture was 38% larger in the anteroposterior dimension with the transtibial versus anteromedial portal technique (mean, 14.9 mm v 10.8 mm; P ≤ .05). The anteromedial portal drilling technique allows for accurate positioning of the femoral socket in the center of the native footprint, resulting in secondary improvement in time-zero control of tibial translation with Lachman and pivot-shift testing compared with conventional transtibial ACL reconstruction. This technique respects the native ACL anatomy but cannot restore it with a single-bundle ACL reconstruction. Eccentric, posterolateral positioning of the guidewire in the tibial tunnel with the transtibial technique results in iatrogenic re-reaming of the tibial tunnel and significant intra-articular aperture expansion. Anteromedial portal drilling of the femoral socket may allow for improved restoration of anatomy and stability with ACL reconstruction compared with conventional transtibial drilling techniques.

Mechanized pivot shift test achieves greater accuracy than manual pivot shift test

The objective of this study was to design a navigated mechanized pivot shift test setup and evaluate its repeatability in the ACL-deficient knee. It was hypothesized that translations and rotations measured with the mechanized pivot shift would be more repeatable when compared to those obtained with a manual pivot shift. Twelve fresh frozen cadaveric hip-to-toe whole lower extremities were used for this study. A manual pivot shift test was performed in the intact knee and in the ACL-deficient knee and was repeated three times. A navigation system simultaneously recorded tibial translation and rotation. The mechanized pivot shift test consists of a modified continuous passive motion (CPM) machine and a custom-made foot holder to allow for the application of internal rotation moments at the knee. Valgus moments were achieved by a 45 degrees tilt of the CPM machine with respect to the supine position and a Velcro strap secured across the proximal tibia. The mechanized pivot shift was repeated three times. Repeated measures ANOVA was used to compare manual and mechanized pivot shift testing. An intra-class correlation coefficient (ICC) was used to determine variability within each knee at each testing condition. In the ACL-deficient knee, translation with manual pivot shift testing (11.7 +/- 2.6 mm) was significantly higher than with mechanized pivot shift testing (7.4 +/- 2.5 mm; p < 0.05). Rotation with the manual pivot shift testing (18.6 +/- 5.4 degrees) was also significantly higher than with mechanized pivot shift testing (11.0 +/- 2.3 degrees; p < 0.05). The intra-class ICC for translations was 0.76 for manual pivot shift and 0.92 for the mechanized pivot shift test. The intra-class ICC for rotations was 0.89 for manual pivot shift and 0.82 for the mechanized pivot shift test. This study introduced a modified CPM for mechanized pivot shift testing. Although recorded translations and rotations with the mechanized pivot shift test were lower than with manual testing, the clinical advantage of mechanized pivot shift testing is a more repeatable measurement of ATT when compared to manual pivot shift testing. This setup may increase consistency of clinical grading of the pivot shift test.