What does it take to have a high-grade pivot shift?

Complications in Anterior Cruciate Ligament Surgery and How to Avoid Them

Complications following anterior cruciate ligament (ACL) reconstruction can be detrimental to a patient's recovery and limit their ability to successfully return to sport. Arthrofibrosis, graft failure, and infection are a few examples of complications that can arise. Therefore, it is important for surgeons to recognize that each step during perioperative surgical decision making can impact patients' risk for such complications. The purpose of this paper is to discuss common complications following ACL reconstruction and how surgeons can avoid or reduce the risk of complications.

Injuries to both anterolateral ligament and Kaplan fiber of the iliotibial band do not increase preoperative pivot-shift phenomenon in ACL injury

Background

To assess the incidence of anterolateral ligament (ALL) and Kaplan fiber of the iliotibial band (KF) injuries in patients with acute anterior cruciate ligament (ACL) injury on magnetic resonance imaging (MRI), and to investigate the association between these injuries and the magnitude of preoperative pivot-shift test.

Method

One-hundred and five patients with primary ACL injury were retrospectively reviewed. ALL injury and KF injury were assessed by preoperative MRI, and subjects were allocated into four groups: Group A, neither injury; Group B, only ALL injury; Group C, only KF injury; Group D, simultaneous ALL and KF injuries. Before ACL reconstruction, tibial acceleration during the pivot-shift test was measured by an electromagnetic measurement system, and manual grading was recorded according to the International Knee Documentation Committee (IKDC) guideline.

Results

In MRI, the ALL was identified in 104 patients (99.1%) and KF in 99 patients (94.3%). ALL and KF injuries were observed in 43 patients (43.9%) and 23 patients (23.5%), respectively. Patient distribution to each group was as follows; Group A: 43 patients (43.9%), Group B: 32 patients (32.7%), Group C: 12 patients (12.2%), Group D: 11 patients (11.2%). No significant differences were observed in tibial acceleration, and manual grading among the four groups.

Conclusion

Simultaneous injury to both ALL and KF was uncommon, and preoperative pivot-shift phenomenon did not increase even in those patients. The finding suggests that the role of ALL and KF in controlling anterolateral rotatory knee laxity may be less evident in the clinical setting compared to a biomechanical test setting.

Correlation Between the Location and Distance of Kissing Contusions and Knee Laxity in Acute Noncontact ACL Injury

BACKGROUND

Bone bruise (BB) and kissing contusion are common features of acute anterior cruciate ligament (ACL) injury on magnetic resonance imaging (MRI). The correlation between the location and distance of kissing contusions and knee laxity remains unclear.

PURPOSE

To determine the significance of different patterns of BB in acute noncontact ACL injury and assess the correlation between the location and distance of kissing contusions and the severity of knee laxity.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 205 patients with acute noncontact ACL injury undergoing arthroscopic treatment between January 2021 and May 2022 were included in this retrospective analysis. Patients were grouped according to the different patterns of BB. The type of ACL injury and concomitant injuries were analyzed on MRI and confirmed by arthroscopy. Anterior knee laxity was assessed by the Ligs digital arthrometer and stress radiography, and rotational knee laxity was assessed by the intraoperative pivot-shift test. The MRI parameters of the location and distance of kissing contusions were measured to assess their correlations with the severity of knee laxity.

RESULTS

Of the 205 patients with acute noncontact ACL injury, 38 were in the non-BB group and 167 were in the BB group, the latter including 32 with the isolated BB on the lateral tibial plateau and 135 with kissing contusions. There was no significant difference in the mean time from initial injury to MRI scan between the non-BB group and the BB group (14.34 ± 2.92 vs 15.17 ± 2.86 days; P = .109) or between the isolated BB subgroup and the kissing contusion subgroup (14.94 ± 2.92 vs 15.23 ± 2.85 days; P = .605). The side-to-side difference (SSD) in anterior knee laxity and the incidences of complete ACL injury, concomitant injuries, and high-grade pivot-shift test were significantly higher in the BB group than in the non-BB group, and in the kissing contusion subgroup compared with the isolated BB subgroup. The kissing contusion index of the lateral femoral condyle (LFC) and the sagittal distance of kissing contusions were significantly correlated with the SSD in anterior knee laxity and the grade of pivot-shift test (P < .001).

CONCLUSION

The presence of BB, in particular the appearance of kissing contusions, was related to greater knee laxity and higher incidences of complete ACL injury and concomitant injuries in acute noncontact ACL injury. For patients with kissing contusions, as the location of BB on the LFC moved forward and the distance between kissing contusions increased, anterior and rotational knee laxity became more serious.

Greater Knee Rotatory Instability After Posterior Meniscocapsular Injury Versus Anterolateral Ligament Injury: A Proposed Mechanism of High-Grade Pivot Shift

Background

For anterolateral rotatory instability as a result of secondary soft tissue injuries in anterior cruciate ligament (ACL)-deficient knees, there is increasing interest in secondary stabilizers to prevent internal rotation (IR) of the tibia.

Purpose

To determine which secondary stabilizer is more important in anterolateral rotatory instability in ACL-deficient knees.

Study Design

Controlled laboratory study.

Methods

The lower extremities of 10 fresh-frozen cadavers (20 extremities) without anterior-posterior or rotational instability were included. Matched-pair randomization was performed, with each side per specimen assigned to 1 of 2 groups. In group 1, the ACL was sectioned, followed by the anterolateral ligament (ALL); in group 2, the ACL was sectioned, followed by sequential sectioning of the posterolateral meniscocapsular complex (PLMCC) and posteromedial meniscocapsular complex (PMMCC). The primary outcome was the change in relative tibial IR during a simulated pivot-shift test with 5 N·m of IR torque and 8.9 N of valgus force. The secondary outcomes were the International Knee Documentation Committee grade in the pivot-shift test and the incidence of the grade 3 pivot shift.

Results

In group 1, compared with baseline, the change in relative tibial IR at 0° of knee flexion was 1.4° (95% CI, -0.1° to 2.9°; P = .052) after ALL release. In group 2, it was 2.5° (95% CI, 0.4° to 4.8°; P = .007) after PLMCC release and 4.1° (95% CI, 0.5° to 7.8°; P = .017) after combined PLMCC and PMMCC release. Combined PLMCC and PMMCC release resulted in greater change of tibial IR with statistical significance at 0°, 15°, and 30° of knee flexion (P = .008, .057, and .004, respectively) compared with ALL release. The incidence of grade 3 pivot shifts was 10% in group 1 and 90% in group 2.

Conclusion

Posterior meniscocapsular laxity caused an increase in relative tibial IR as much as ALL injury in ACL-deficient knees in our simulated laboratory test, and greater anterolateral rotatory instability occurred with posterior meniscocapsular injury compared with ALL injury.

Clinical Relevance

Repair of the injured posterior meniscocapsular complex may be an important treatment option for reducing anterolateral rotatory instability in the ACL-deficient knee.

ANTEROMEDIAL OR CENTRAL ANATOMIC ACL RECONSTRUCTION? A CADAVERIC HIP-TO-TOE STUDY

Objective

To compare anatomic anterior cruciate ligament (ACL) reconstruction between two tunnel positions in knees with isolated ligament tears.

Methods

Anatomic ACL reconstruction was performed, from hip-to-toe, on 15 fresh cadaveric specimens. No associated lesions were created to enhance knee instability. The protocol was conducted in three states: (1) complete isolated ACL deficiency; (2) anatomic femoral and tibial anteromedial ACL reconstruction (AM REC); and (3) anatomic femoral and tibial central ACL reconstruction (Central REC). The reconstruction protocols were randomly assigned. The continuous mechanized pivot-shift test was recorded dynamically with a tracking system.

Results

The Central REC group showed a smaller degree of internal rotation (0.6° ± 0.3° vs. 1.8° ± 0.3°, respectively, P < 0.05) and no difference in anterior translation (4.7 mm ± 0.4 mm vs. 4.5 mm ± 0.4 mm, respectively, P > 0.05) in the pivot-shift test, compared with the AM REC group.

Conclusion

The central anatomic ACL reconstruction resulted in greater restriction of internal rotation than the anteromedial anatomic ACL reconstruction. Experimental Study on Cadaver.

Pivot Shift Syndrome of the Knee

The pivot shift test, in contrast to the Lachman or anterior drawer, is a manually subjective clinical test that simulates the injury mechanism. It is the most sensitive test to determine ACL insufficiency. This paper reviews the history, development, research, and treatment associated with the pivot shift phenomenon which is associated with tearing and loss of function of the knee anterior cruciate ligament. The pivot shift test most closely recapitulates what the symptomatic anterior cruciate ligament deficient patient feels is happening which is an abnormal translation and rotation of the injured joint during flexion or extension. The test is best conducted in the relaxed patient by applying knee flexion, tibial external rotation, and valgus stress. The pivot shift biomechanics and treatment measures are reviewed.

Anatomical and Biomechanical Characteristics of the Anterolateral Ligament: A Descriptive Korean Cadaveric Study Using a Triaxial Accelerometer

Background and Objectives: The anterolateral ligament (ALL) could be the potential anatomical structure responsible for rotational instability after anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to investigate the anatomical and biomechanical characteristics of the ALL in Korean cadaveric knee joints. Materials and Methods: Twenty fresh-frozen cadaveric knees were dissected and tested. Femoral and tibial footprints of the ALL were recorded. Pivot shift and Lachman tests were measured with KiRA. Results: The prevalence of ALL was 100%. The average distance of the tibial footprint to the tip of the fibular head was 19.85 ± 3.41 mm; from the tibial footprint to Gerdy's tubercle (GT) was 18.3 ± 4.19 mm; from the femoral footprint to the lateral femoral epicondyle was 10.25 ± 2.97 mm. ALL's footprint distance was the longest at 30° of flexion (47.83 ± 8.05 mm, p < 0.01) in a knee with intact ALL-ACL and neutral rotation. During internal rotation, the footprint distance was the longest at 30° of flexion (50.05 ± 8.88 mm, p < 0.01). Internal rotation produced a significant increase at all three angles after ACL-ALL were transected (p = 0.022), where the footprint distance was the longest at 30° of flexion (52.05 ± 7.60 mm). No significant difference was observed in KiRA measurements between intact ALL-ACL and ALL-transected knees for pivot shift and Lachman tests. However, ACL-ALL-transected knees showed significant differences compared to the intact ALL-ACL and ALL-transected knees (p < 0.01). Conclusions: The ALL was identified as a distinct ligament structure with a 100% prevalence in this cadaveric study. The ALL plays a protective role in internal rotational stability. An isolated ALL transection did not significantly affect the ALL footprint distances or functional stability tests. Therefore, the ALL is thought to act as a secondary supportive stabilizer for rotational stability of the knee joint in conjunction with the ACL.

Posterior tibial plateau impaction fractures are not associated with increased knee instability: a quantitative pivot shift analysis

PURPOSE

This study aimed to evaluate posterolateral tibial plateau impaction fractures and how they contribute to rotatory knee laxity using quantitative pivot shift analysis. It was hypothesised that neither the presence of nor the degree of involvement of the plateau would affect rotatory knee laxity in the ACL-deficient knee.

METHODS

A retrospective review of prospectively collected data on 284 patients with complete anterior cruciate ligament (ACL) injuries was conducted. Posterolateral tibial plateau impaction fractures were identified on preoperative MRI. The patients were divided into two cohorts: "fractures" or "no fractures". The cohort with fractures was further categorised based on fracture morphology: "extra-articular", "articular-impaction", or "displaced-articular fragment". All data were collected during examination under anaesthesia performed immediately prior to ACL reconstruction. This included a standard pivot shift test graded by the examiner and quantitative data including anterior tibial translation (mm) via Rolimeter, quantitative pivot shift (QPS) examination (mm) via PIVOT tablet technology, and acceleration (m/sec²) during the pivot shift test via accelerometer. Quantitative examinations were compared with the contralateral knee.

RESULTS

There were 112 patients with posterolateral tibial plateau impaction fractures (112/284, 39%). Of these, 71/112 (63%) were "extra-articular", 28/112 (25%) "articular-impaction", and 13/112 (12%) "displaced-articular". Regarding the two groups with or without fractures, there was no difference in subjective pivot shift (2 ± 0 vs 2 ± 0, respectively,  n.s.), QPS (2.4 ± 1.6 mm vs 2.7 ± 2.2 mm, respectively, n.s.), anterior tibial translation measurements (6 ± 3 mm vs 5 ± 3 mm, respectively, n.s.), or acceleration of the knee during the pivot (1.7 ± 2.3 m/s² vs 1.8 ± 3.1 m/s², respectively, n.s.). When the fractures were further subdivided, subgroup analysis revealed no significant differences noted in any of the measured examinations between the fracture subtypes.

CONCLUSION

This study showed that the posterolateral tibial plateau impaction fractures are commonly encountered in the setting of ACL tears; however, contrary to previous reports, they do not significantly increase rotatory knee laxity. This suggests that this type of concomitant injury may not need to be addressed at the time of ACL reconstruction.

LEVEL OF EVIDENCE

Level III.

The Incidence of Posterolateral Tibial Plateau and Central Lateral Femoral Condylar Impaction Fractures in a Pediatric and Young Adult Population

BACKGROUND

Posterolateral tibial plateau and central lateral femoral condylar impaction fractures are known to occur in the setting of anterior cruciate ligament (ACL) tears. There have been no prior investigations into the incidence and morphology of posterolateral tibial plateau impaction fractures in the setting of ACL injury in a pediatric population.

METHODS

Patients between 9 and 22 years of age with knee magnetic resonance imagings (MRIs) performed demonstrating complete or partial ACL tear were included in this study. MRI reports were reviewed to denote the presence of posterior cruciate ligament, medial collateral ligament, or lateral collateral ligament injury, meniscus tears, cartilage lesions. MRIs were reviewed by 2 fellowship-trained orthopaedic surgeons to denote the presence of posterolateral tibial plateau and central lateral femoral condylar impaction fractures and physeal status of femoral and tibial physes. Statistical analysis performed included χ 2 analysis and the Student t testing.

RESULTS

A total of 328 patients with a primary ACL tear were identified. The mean age of patients included was 16.5 years (range: 9.0-21.5). The incidence of posterolateral tibial plateau impaction fractures was 83/328 (25.3%) while the incidence of lateral femoral condylar impaction fractures was 119/328 (36.3%). Bipolar impaction fractures occurred in 37/328 (11.3%). Of the 83 tibial impaction fractures identified, 82 were low-grade morphologic subtypes. Patients with lateral tibial plateau impaction fractures were older than those with no fracture (17.2±2.2 vs. 16.3±2.1, P =0.001). Only 3/38 (7.9%) patients with an open tibial physis sustained a tibial plateau impaction fracture compared with 80/290 (27.6%) with a closed tibial physis (χ 2 value: 6.9, P =0.009). There was no difference in proportion of patients with lateral femoral condylar impaction fractures based on femoral physeal status ( P =0.484).

CONCLUSION

The incidence of posterolateral tibial plateau impaction fractures in the setting of ACL tear in a pediatric and young adult patient population appears to be lower while lateral femoral condylar impaction fractures occur more frequently when comparing to previously reported incidences found in adult populations in the literature. Furthermore, posterolateral tibial plateau impaction fractures occur less frequently in those with an open proximal tibial physis and high-grade posterolateral tibial plateau bone loss is exceedingly rare in pediatric and young adult patients. Lateral femoral condylar impaction fractures are associated with lateral meniscal tears and medial meniscal ramp lesions.

LEVEL OF EVIDENCE

Level IV-cross-sectional study.

Extent of posterolateral tibial plateau impaction fracture correlates with anterolateral complex injury and has an impact on functional outcome after ACL reconstruction

PURPOSE

The impact of posterolateral tibial plateau impaction fractures (TPIF) on posttraumatic knee stability in the setting of primary anterior cruciate ligament (ACL) tear is unknown. The main objective was to determine whether increased bone loss of the posterolateral tibial plateau is associated with residual rotational instability and impaired functional outcome after ACL reconstruction.

METHODS

A cohort was identified in a prospective enrolled study of patients suffering acute ACL injury who underwent preoperative standard radiographic diagnostics and clinical evaluation. Patients were included when scheduled for isolated single-bundle hamstring autograft ACL reconstruction. Exclusion criteria were concurrent anterolateral complex (ALC) reconstruction (anterolateral tenodesis), previous surgery or symptoms in the affected knee, partial ACL tear, multi-ligament injury with an indication for additional surgical intervention, and extensive cartilage wear. On MRI, bony (TPIF, tibial plateau, and femoral condyle morphology) and ligament status (ALC, concomitant collateral ligament, and meniscus injuries) were assessed by a musculoskeletal radiologist. Clinical evaluation consisted of KT-1000, pivot-shift, and Lachman testing, as well as Tegner activity and IKDC scores.

RESULTS

Fifty-eight patients were included with a minimum follow-up of 12 months. TPIF was identified in 85% of ACL injuries (n = 49). The ALC was found to be injured in 31 of 58 (53.4%) cases. Pearson analysis showed a positive correlation between TPIF and the degree of concomitant ALC injury (p < 0.001). Multiple regression analysis revealed an increased association of high-grade TPIF with increased lateral tibial convexity (p = 0.010). The high-grade TPIF group showed worse postoperative Tegner scores 12 months postoperatively (p = 0.035).

CONCLUSION

Higher degrees of TPIFs are suggestive of a combined ACL/ALC injury. Moreover, patients with increased posterolateral tibial plateau bone loss showed lower Tegner activity scores 12 months after ACL reconstruction.

LEVEL OF EVIDENCE

III.

Reliable ligamentous stability and high return-to-sport rates after arthroscopic reduction and internal fixation of tibial eminence fractures

PURPOSE

To investigate functional and clinical outcomes, and physical activity after arthroscopic suture fixation of tibial eminence fractures with regard to postoperative stability, range of motion (ROM), complications, and return to sports.

METHODS

Patients undergoing arthroscopic reduction and internal fixation (ARIF) of tibial eminence fractures using a suture fixation technique were included. Outcome was evaluated retrospectively after a minimum follow-up of 24 months using KT-1000 arthrometer measurements, clinical examination, outcome scores (Lysholm score, Tegner Activity Scale), and a questionnaire about sport activities.

RESULTS

A total of 23 patients (44% male, 57% female) with a mean age of 25 ± 15 years were included. Mean follow-up was 57 ± 25 months. KT-1000 arthrometer measurements of anterior tibial translation revealed a mean side-to-side difference of 0.9 ± 1.0 mm. Clinical examination showed 100% normal or nearly normal anterior translation of the tibia. Two patients (9%) received an ACL reconstruction due to traumatic ACL re-instability and were, therefore, considered as failures. An extension deficit concerning hyperextension occurred in 29% of patients postoperatively. Further postoperative complications occurred in 14% of patients and included postoperative stiffness with ROM limitations and secondary dislocation of a fragment. Mean postoperative Lysholm score was 89 ± 14. Comparing pre- and postoperative values, no significant change of the Tegner Activity Scale was observed. All patients (failures excluded) returned to high impact sports activities after ARIF.

CONCLUSION

Excellent reliable ligamentous stability and high rates of return to high impact sports can be expected after ARIF using a suture fixation technique for type II-IV tibial eminence fractures. Complications, such as limitations in ROM, commonly occur in up to 30% after ARIF. Therefore, regular follow-up examinations remain important in this usually young patient cohort.

LEVEL OF EVIDENCE

Level IV.

High-grade pivot-shift phenomenon after anterior cruciate ligament injury is associated with asymmetry of lateral and medial compartment anterior tibial translation and lateral meniscus posterior horn tears

PURPOSE

To investigate whether the high-grade pivot-shift phenomenon is associated with asymmetry of the lateral and medial compartment anterior tibial translation (L-ATT and M-ATT) and lateral meniscus posterior horn (LMPH) tears in anterior cruciate ligament (ACL) injuries.

METHODS

A retrospective analysis was performed on 192 consecutive patients who had complete ACL injuries between January 2019 and December 2020. Among these, 156 met the inclusion criteria. L-ATT and M-ATT were measured using preoperative weight-bearing magnetic resonance imaging (MRI), and the differences between L-ATT and M-ATT were calculated. Thirty-five patients who demonstrated excessive differences in L-ATT and M-ATT (> 6.0 mm) were regarded as asymmetric (study group), and 36 patients with minimal or no differences in L-ATT and M-ATT (< 3.0 mm) were allocated to the control group. Demographic data, grade of the pivot-shift test, integrality of LMPH, and medial meniscus posterior horn (MMPH) were compared between the groups. Moreover, predictors of high-grade pivot-shift phenomenon, including asymmetry of L-ATT and M-ATT, integrity of LMPH and MMPH, time from injury to surgery, sex, age, and body mass index (BMI) were assessed using multivariable logistic regression analysis.

RESULTS

The difference between L-ATT and M-ATT in the study group was significantly higher than that in the control group (mean ± SD: 8.4 ± 2.1 mm vs. 1.5 ± 1.0 mm, P < 0.001). A higher proportion of patients with high-grade pivot-shift phenomenon (2 + and 3 +) and LMPH tears were identified in the study group (high-grade pivot-shift phenomenon: 25/35 vs. 13/36, P = 0.003; LMPH tears: 18/35 vs. 5/36, P = 0.001). Additionally, asymmetry of L-ATT, M-ATT (odds ratio 5.8; 95% CI 1.7-19.8; P = 0.005), and LMPH tears (odds ratio 3.8; 95% CI 1.3-11.6; P = 0.018) were found to be good predictors of the high-grade pivot-shift phenomenon after ACL injury, whereas MMPH tears, time from injury to surgery, sex, age, and BMI were not.

CONCLUSION

In patients with ACL injury, the high-grade pivot-shift phenomenon is associated with asymmetry between L-ATT and M-ATT, and LMPH tears.

LEVEL OF EVIDENCE

III.

Anterior cruciate ligament rupture and associated Segond fracture: Incidence and effect on associated ligamentous and meniscal injuries

Introduction

The Segond fracture is an avulsion fracture of the lateral tibial plateau and is widely considered to be pathognomonic of anterior cruciate ligament (ACL) rupture. In addition to ACL rupture, Segond fractures have also been noted to be associated with significant intra-articular pathology such as meniscal injuries as well as extra-articular pathology such as collateral ligament injuries. This is likely due to the fact that the presence of a Segond fracture may represent increased rotatory instability. Whilst several studies have demonstrated the association of a Segond fracture with significant intra-articular pathology, there is a paucity of literature assessing if the combination of an ACL rupture and Segond fracture gives rise to higher rates of concomitant ligamentous and meniscal injuries. The primary objective of this study is to determine if patients with ACL ruptures associated with Segond fractures have higher rates of concomitant ligamentous and meniscal injury, when compared to patients with ACL ruptures without a Segond fracture.

Methods

A retrospective review of all patients who underwent ACL reconstruction in a single institution between 2014 to 2018 was conducted. A review of the patients’ demographics, operative notes, and radiographs was performed. X-rays and MRI scans were double-read by a board-certified radiologist and Orthopaedic surgeon.

Results

A total of 414 subjects were included. The incidence of Segond fracture was 2.4%. The mean age was 24.7±7.4 (range 16 to 60) years and 26.7±7.6 (range 16 to 38) years in patients with and without Segond fractures respectively. 89.9% of patients suffered a non-contact mechanism of injury, with sports injuries being most common (79.5%). There was a significantly higher rate of isolated lateral meniscus tears in patients with Segond fractures compared to those without (50% v.s. 20.8%) based on pre-operative MRI. (p<0.05) There were no other significant differences in associated ligamentous injuries.

Conclusion

The incidence of Segond fracture associated with ACL rupture is 2.4%. There is a significantly higher risk of a concomitant isolated lateral meniscus tear in ACL ruptures associated with a Segond fracture. There is no significantly higher risk of concomitant ligamentous injuries in ACL ruptures associated with a Segond fracture.

Ipsilateral ACL injured patients with Segond fractures demonstrate increased posterior tibial slope

BACKGROUND

The anterolateral complex has been demonstrated to assist with rotational stability and prevention of anterior tibial translation during the pivot shift. In this study the Segond fracture is used as a surrogate for an anterolateral complex injury to determine if there is an association between Segond fracture and increased posterior tibial slope.

METHODS

Patients' charts and radiographs were analyzed retrospectively for the presence of Segond fractures on injury radiographs. These patients, the Segond cohort, were then age and gender matched to a control cohort. Demographic as well MRI measurements of medial and lateral posterior tibial slope and lateral-to-medial slope asymmetry were collected for each cohort. Secondary outcome of anterior cruciate ligament reconstruction failure data was also collected.

RESULTS

The Segond group demonstrated a statistically significantly greater lateral posterior tibial slope (8.42° versus 6.55°, P = 0.003) as well as medial posterior tibial slope (6.57° versus 5.34° degrees, P = 0.045). There was no significant differences between lateral-to-medial asymmetry (2.18°versus 1.83°, P = 0.246).

CONCLUSION

Patients with Segond fractures at the time of anterior cruciate ligament injury have increased medial and lateral posterior tibial slope. This may relate to increased rotational and translational instability associated with anterolateral complex injuries. Surgeons treating these patient may use this information to counsel their patients on the risks of associated pathology at the time of arthroscopy such as lateral meniscal posterior root tears.

Latin American formal consensus on the appropriate indications of extra-articular lateral procedures in primary anterior cruciate ligament reconstruction

OBJECTIVES

To create a practice guideline for the appropriate indications of an extra-articular procedure in primary anterior cruciate ligament reconstruction (ACLR).

METHODS

The formal consensus method described by the Haute Autorité de Santé was used. The Latin American Society of Arthroscopy, Articular Replacement, and Sports Injuries (SLARD) recruited three groups of experts on ACLR. Initially, the steering group, consisting of eight surgeons, performed a systematic review of the literature and elaborated on 192 scenarios for primary ACLR. The rating group, composed of 23 surgeons, rated each scenario in two rounds, with an in-between in-person meeting for discussion. Median scores and agreement levels were estimated to classify each scenario as inappropriate, uncertain or appropriate for adding anterolateral reconstruction. Finally, the lecture group, consisting of 10 surgeons, revised each stage of the method, results and interpretation.

RESULTS

Of the scenarios, 11.97% were rated as appropriate for adding an extra-articular lateral procedure, 7.81% as inappropriate and 80.21% as uncertain. The key recommendations for the addition of extra-articular lateral techniques were as follows: it is appropriate when the patient is under 25 years of age, has high-grade physical examination findings, practises a pivoting sport and has hyperlaxity; meanwhile, it is inappropriate when the patient has low-grade physical examination findings, has normal laxity and does not practise a pivoting sport.

CONCLUSIONS

The appropriate indications of extra-articular lateral procedures in primary ACLR were determined on the basis of the best available evidence and expert opinion following a formal consensus method.

LEVEL OF EVIDENCE

V.

The presence of high-grade pivot shift test preoperatively is associated with inferior functional outcomes

BACKGROUND

The effect of high-grade preoperative pivot shift test on outcomes of anterior cruciate ligament (ACL) reconstruction surgery is not very well established. The present study was conducted to study the factors associated with high-grade pivot shift test and effect of high-grade preoperative pivot shift test on functional outcomes after ACL reconstruction surgery.

METHODS

Three hundred and sixty-two patients who underwent primary ACL reconstruction surgery were enrolled in the study. The pivot shift test was performed preoperatively under anesthesia in all patients. Side of the meniscal tear, if present at the time of ACL reconstruction, was documented. Patients were divided into two groups depending upon the grade of pivot shift test: group H, high-grade pivot shift (n = 84/362; 23%); and group L, low-grade pivot shift (n = 278/362; 77%). Patients were further divided into two groups depending upon the duration of injury: acute (<6 months) and chronic (>6 months). The functional assessment was done using Lysholm score and Tegner activity scale.

RESULTS

The presence of lateral meniscus tear (27/84 vs. 53/278) or both menisci tear (29/84 vs. 60/278) was associated with high-grade pivot shift (p < 0.05). Chronic ACL tears were also observed to be associated with high-grade pivot shift (p = 0.03). The mean Lysholm score in group H and group L patients was 93.8 ± 5.1 and 95.2 ± 5.3, respectively (p = 0.04). The mean post-op Tegner activity scale in group H was 6.8 and in group L was 7.3 (p = 0.0001). Also, 181/253 (71.5%) patients returned to same or higher level of sports activity in group L as compared to 33/72 (46%) patients in group H. The incidence of graft failure in groups H and L was 6.5% (5/77) and 1.6% (4/257; p = 0.03), respectively.

CONCLUSIONS

The high-grade pivot shift is associated with chronic ACL tear (>6 months) and concomitant lateral meniscus tear. The presence of high-grade pivot shift preoperatively is associated with inferior clinical outcomes and lower rate of return to sports.

LEVEL OF EVIDENCE

Level IV, case-control study.

Grade III pivot shift as an early sign of knee decompensation in chronic ACL-injured knees with bimeniscal tears

PURPOSE

To analyse possible associations between the preoperative pivot shift (PS) test and both patient and injury characteristics in anterior cruciate ligament (ACL)-injured knees, considering previously neglected meniscal injuries such as ramp and root tears. The hypothesis was that a preoperative grade III PS was associated with the amount of intra-articular soft-tissue damage and chronicity of the injury.

METHODS

The cohort involved 376 patients who underwent primary ACL reconstruction (239 males/137 females; median age 26). Patients were examined under anesthesia before surgery, using the PS test. During arthroscopy, intra-articular soft-tissue damage of the injured knee was classified as: (1) partial ACL tear; (2) complete isolated ACL tear; (3) complete ACL tear with one meniscus tear; and (4) complete ACL and bimeniscal tears. Chi-square and Mann-Whitney U tests were used to evaluate whether sex, age, body mass index, sport at injury, mechanism of injury, time from injury and intra-articular damage (structural damage of ACL and menisci) were associated with a grade III PS. Intra-articular damage was further analyzed for two sub-cohorts: acute (time from injury ≤ 6 months) and chronic injuries (> 6 months).

RESULTS

A grade III PS test was observed in 26% of patients. A significant association with PS grading was shown for age, time from injury and intra-articular soft-tissue damage (p < 0.05). Further analyses showed that grade III PS was associated with intra-articular damage in chronic injuries only (p < 0.01). In complete ACL and bimeniscal tears, grade III PS was more frequent in chronic (53%) than in acute knee injuries (26%; p < 0.01). Patients with chronic complete ACL and bimeniscal tears had a grade III PS 3.3 [1.3-8.2] times more often than patients in the acute sub-cohort.

CONCLUSION

In ACL-injured patients, a preoperative grade III PS was mainly associated with a higher amount of intra-articular soft-tissue damage and chronicity of the injury. Patients with complete chronic ACL injuries and bimeniscal tears were more likely to have a preoperative grade III PS than their acute counterparts. This suggests that grade III PS may be an early sign of knee decompensation of dynamic rotational knee laxity in chronic ACL-injured knees with bimeniscal lesions.

LEVEL OF EVIDENCE

Level III.

The diagnostic accuracy of clinical tests for anterior cruciate ligament tears are comparable but the Lachman test has been previously overestimated: a systematic review and meta-analysis

PURPOSE

The diagnostic accuracy of clinical tests for anterior cruciate ligament injury has been reported in previous systematic reviews. Numerous studies in these reviews include subjects with additional knee ligament injury, which could affect the sensitivity of the tests. Meta-analyses have also been performed using methods that do not account for the non-independence of sensitivity and specificity, potentially overestimating diagnostic accuracy. The aim of this study was to report the diagnostic accuracy of clinical tests for anterior cruciate ligament tears (partial and complete) without concomitant knee ligament injury.

METHODS

A systematic review with meta-analysis was performed according to the PRISMA guidelines. Meta-analyses included studies reporting the specificity and/or sensitivity of tests with or without concomitant meniscal injury. Where possible, pooled diagnostic estimates were calculated with bivariate random-effects modelling to determine the most accurate effect sizes. Diagnostic accuracy values are presented for the anterior drawer, Lachman, Lever sign and pivot shift tests overall and in acute or post-acute presentations.

RESULTS

Pooled estimates using a bivariate model for overall sensitivity and specificity respectively were as follows: anterior drawer test 83% [95% CI, 77-88] and 85% [95% CI, 64-95]; Lachman test 81% [95% CI, 73-87] and 85% [95% CI, 73-92]; pivot shift test 55% [95% CI, 47-62] and 94% [95% CI, 88-97]; Lever sign test 83% [95% CI, 68-92] and 91% [95% CI, 83-95]. For specific presentations, the sensitivity and specificity of the Lachman test, respectively, were: complete tears 68% [95% CI, 54-79] and 79% [95% CI, 51-93]; post-acute injuries 70% [95% CI, 57-80] and 77% [95% CI, 53-91].

CONCLUSIONS

The pivot shift and Lever sign were the best tests overall for ruling in or ruling out an anterior cruciate ligament tear, respectively. The diagnostic accuracy of the Lachman test, particularly in post-acute presentations and for complete tears, is lower than previously reported. Further research is required to establish more accurate estimates for the Lachman test in acute presentations and partial ligament tears using bivariate analysis.

LEVEL OF EVIDENCE

III.

Anterolateral Ligament Reconstruction Improves Anteroposterior Stability As Well As Rotational Stability in Revision Anterior Cruciate Ligament Reconstruction with High-Grade Pivot Shift

This study aimed to investigate the effect of anterolateral ligament reconstruction (ALLR) in revision anterior cruciate ligament reconstruction (ACLR) with high-grade pivot shift. The hypothesis was that revision ACLR combined with ALLR (RACLR with ALLR group) would show superior clinical outcomes to those of isolated revision ACLR. We retrospectively evaluated consecutive patients who underwent revision ACLR (RACLR) combined with ALLR between October 2015 and January 2017. The indication for combination of ALLR with revision ACLR was failed ACLR with ≥G2 pivot-shift instability. The control group included patients who underwent isolated revision ACLR (isolated RACLR group) for the same indication between July 2013 and September 2015. Exclusion criteria were ≤G1 pivot-shift instability, multiple ligament reconstruction, bilateral ligament injury, double-bundle reconstruction, insufficient medical records, postoperative infection, and follow-up loss at postoperative 2 years. Clinical scores, stability tests, and failure rates were compared between groups at the 2-year follow-up. The RACLR with ALLR group had 18 patients (mean age, 32.9 ± 10.8 years) and the RACLR group had 21 patients (mean age, 29.6 ± 10.2 years). Clinical scores at the 2-year follow-up showed no significant differences between groups. However, the RACLR with ALLR group showed better stability in the Lachman test (p = 0.005), pivot-shift test (p = 0.030), and side-to-side difference in stress radiographs (3.9 ± 3.0 mm vs. 5.9 ± 2.8 mm, p = 0.018) than the isolated RACLR group. The RACLR with ALLR group had two failures (11.1%), and the RACLR group had three failures (14.3%). In conclusion, ALLR in revision ACLR with high-grade pivot shift improves anteroposterior stability as well as rotational stability at 2-year follow-up. Therefore, ALLR is recommended with revision ACLR, especially in patients with high-grade pivot shift. This is a Level III, retrospective cohort review.

Incidence and Risk Factors for Residual High-Grade Pivot Shift After ACL Reconstruction With or Without a Lateral Extra-articular Tenodesis

Background

Residual rotatory knee laxity at midterm follow-up after isolated anterior cruciate ligament reconstruction (ACLR) versus ACLR with lateral extra-articular tenodesis (LET) remains an issue.

Purpose/Hypothesis

To evaluate the outcomes of ACLR with or without additional LET at a minimum 2-year follow-up in patients with preoperative high-grade pivot shift (PS). Our hypothesis was that the addition of LET would decrease the risk of secondary meniscal injury and the presence of residual high-grade PS at follow-up.

Study Design

Cohort study; Level of evidence, 3.

Methods

A retrospective analysis performed at 3 sports medicine centers identified 266 study patients; all had a high-grade PS (grade 2 or 3) preoperatively and underwent isolated ACLR with or without LET. Four different ACLR techniques were used: single-strand quadrupled semitendinosus (ST4) ACLR without LET (ST4 group; n = 55), ST4 with anatomic LET (ST4+LET group; n = 77), bone-patellar tendon and modified Lemaire LET (BTB+LET group; n = 43), and quadriceps tendon and modified Lemaire LET (QT+LET group; n = 91). At follow-up, we evaluated for the presence of high-grade (grade ≥2) PS. Preoperative meniscal tears and their treatment were recorded.

Results

Overall, 185 (69.5%) patients had at least 1 meniscal tear at index surgery. The mean follow-up period was 44.3 months; 47 (17.7%) patients had a new meniscal tear and 64 (24%) patients had a high-grade PS at follow-up. Compared with meniscal repair, significant predictors for high-grade PS at follow-up were meniscectomy (odds ratio [OR] = 2.65 [95% CI, 1.19-5.63]; P = .02) and nonrepair of preoperative meniscal tear (OR = 3.26 [95% CI, 1.27-9.43]; P = .007). The appearance of a new symptomatic meniscal tear was the strongest significant predictor of high-grade PS at follow-up (OR = 4.31 [95% CI, 2.31-8.06]; P < .001). No significant correlation was observed between the addition of LET and the presence of high-grade PS at follow-up.

Conclusion

In the current study, 1 in 4 patients with high-grade PS before ACLR with or without LET was at risk of residual rotatory knee laxity at mean 44-month follow-up, regardless of the technique used. Repairing a pre-existing meniscal lesion was more effective than performing LET to decrease the presence of a high-grade PS at follow-up.

Association Between Radiological Evidence of Kaplan Fiber Injury, Intraoperative Findings, and Pivot-Shift Grade in the Setting of Acute Anterior Cruciate Ligament Injury

BACKGROUND

Biomechanical studies have suggested that the Kaplan fibers (KFs) of the iliotibial band play a role in controlling anterolateral rotation of the knee. There is a paucity of clinical information on whether injury to the KF in the setting of anterior cruciate ligament (ACL) rupture contributes to increased rotatory laxity of the knee.

PURPOSE/HYPOTHESIS

The purpose was to evaluate the association among radiological evidence of KF injury, intraoperative arthroscopic findings, and grade of pivot shift at the time of ACL reconstruction (ACLR). It was hypothesized that KF injury would be associated with increased injury to the lateral compartment of the knee and a higher grade of pivot shift.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective magnetic resonance imaging (MRI) analysis was conducted on 267 patients with ACL-injured knees who underwent primary ACLR. Patients who had MRI and surgery within 60 days of injury were included (mean age, 23.6 years); there were 158 (59.2%) male patients. MRI was performed using standard knee protocols, and diagnostic criteria were applied to identify KF injury. Associations were made among MRI findings, intraoperative findings, and grade of pivot shift with the patient examined under anesthesia at the time of ACLR. A comparison was made between patients with and without radiological evidence of KF injury.

RESULTS

The prevalence of KF injury was 17.6% (47/267 patients). Arthroscopic evidence of lateral meniscal injury was associated with KF injury (KF intact, 31%; KF injured, 55%; P = .010). The majority of patients in the intact and injured KF groups had a grade 2 pivot shift (75% and 70%, respectively). A minority had grade 3 pivot shift: 5% in the intact group versus 6.4% in the injured group. There was no association between radiological evidence of KF injury and pivot-shift grade (P = .600).

CONCLUSION

In acute ACL injury, KF injuries were not very common (17.6%), and the rate of grade 3 pivot shift was low (5.2%). When present, KF injuries were not associated with a higher-grade pivot shift. However, there was an association between KF injury and lateral meniscal tears identified at the time of ACLR. The role of KFS in controlling anterolateral rotatory laxity in the acute ACL injury in the clinical setting may be less evident when compared with the biomechanical setting.

Effects of Anterolateral Structure Augmentation on the In Vivo Kinematics of Anterior Cruciate Ligament-Reconstructed Knees

BACKGROUND

Double-bundle anterior cruciate ligament (ACL) reconstruction (ACLR) is a well-known treatment that restores the stability of ACL-deficient knees. However, some isolated ACL-reconstructed knees ultimately show rotatory laxity and develop osteoarthritis. Whether combined ACLR with anterolateral structure (ALS) augmentation (ALSA) can provide better improvement in the in vivo knee rotational kinematics remains unknown.

HYPOTHESIS

When compared with isolated double-bundle ACLR, combined double-bundle ACLR with ALSA can improve knee in vivo rotational kinematics and provide better restoration of knee kinematics.

STUDY DESIGN

Controlled laboratory study.

METHODS

Sixteen patients with unilateral ACL injury were randomly divided into 2 groups to receive either combined double-bundle ACLR and ALSA (ALSA group) or isolated double-bundle ACLR (ACLR group). All patients performed a single-leg lunge using the operative and nonoperative/contralateral legs under dual-fluoroscopic imaging system surveillance during a hospital visit at a minimum 1 year (12-13 months) of follow-up to assess the 6 degrees of freedom knee kinematics. Functional evaluation using the Lysholm and Marx rating scales and clinical examinations were also performed.

RESULTS

From full extension to approximately 90° of knee flexion at 5° intervals, the mean ± SD internal rotation of the reconstructed knees in the ALSA group (1.5°± 0.9°) was significantly smaller than that of the contralateral knees (8.2°± 1.9°; P = .008). The ALSA group knees also showed significantly (P = .045) more medial translation than the contralateral knees. In the ACLR group, the mean internal rotation of the reconstructed knee (6.0°± 2.1°) was significantly smaller than that of the contralateral knees (8.9°± 0.6°; P < .001). At full extension, the tibia was significantly more externally rotated than that of the contralateral legs (0.5°± 7.4° vs 7.6°± 3.4°, P = .049).

CONCLUSION

When compared with isolated double-bundle ACLR, double-bundle ACLR augmented with ALS reconstruction resulted in anterolateral rotatory overconstraint during the lunge motion.

CLINICAL RELEVANCE

Additional ALSA of double-bundle ACL-reconstructed knees overconstrained rotatory stability. Therefore, the use of ALSA for ACL-reconstructed knees should be considered with caution for patients with ACL deficiency and anterolateral rotatory instability. Longer-term follow-up to evaluate long-term outcomes and altered kinematics over time is recommended.

The Lateral Femoral Notch Sign Is Correlated With Increased Rotatory Laxity After Anterior Cruciate Ligament Injury: Pivot Shift Quantification With A Surgical Navigation System

BACKGROUND

The lateral femoral notch sign (LNS) is a bony impression on the lateral femoral condyle correlated with anterior cruciate ligament (ACL) injury. Its presence is associated with lateral meniscal injury and higher cartilage degradation on the lateral femoral condyle.

PURPOSE/HYPOTHESIS

The purpose was to investigate the effect of the presence and magnitude of LNS on rotatory instability. The hypothesis was that a positive LNS is correlated with a high-grade pivot shift (PS).

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 90 consecutive patients with complete ACL tears between 2013 and 2017 underwent intraoperative kinematic evaluation with the surgical navigation system and were included in the present study. The same surgeon performed a standardized PS under anesthesia. The PS was quantified through the acceleration of the lateral compartment during tibial reduction (PS ACC) and the internal-external rotation (PS IE). Presence and depth of LNS were evaluated on sagittal magnetic resonance images (1.5-T).

RESULTS

In 47 patients, the LNS was absent; in 33, the LNS depth was between 1 mm and 2 mm; and in 10 patients, it was deeper than 2 mm. Patients with a notch deeper than 2 mm showed increased PS ACC and PS IE compared with the group without the LNS. However, no significant differences were present between the group with a notch between 1 and 2 mm and the patients without LNS. Receiver operating characteristic curve analysis showed that 2 mm was the most predictive cutoff value to identify the "high-grade rotatory instability" group, with an accuracy of 77.8% and 74.4% and a specificity of 95.5% and 93.9% referred to the PS ACC and PS IE, respectively.

CONCLUSION

The presence of a lateral LNS deeper than 2 mm could be used for the preoperative identification of patients with a high risk of increased rotatory instability.

A Biomechanical Study of Pivot-Shift and Lachman Translations in Anterior Cruciate Ligament-Sectioned Knees, Anterior Cruciate Ligament-Reconstructed Knees, and Knees With Partial Anterior Cruciate Ligament Graft Slackening: Instrumented Lachman Tests Statistically Correlate and Supplement Subjective Pivot-Shift Tests

PURPOSE

To determine the statistical and predictive correlation between instrumented Lachman and pivot-shift tests with progressive loss of anterior cruciate ligament (ACL) function.

METHODS

The kinematic correlations between pivot-shift and Lachman anterior tibial translations (ATTs) in ACL-deficient and ACL-reconstructed states and in partially lax ACL grafts were determined with precise robotic testing in cadaveric knees. The Lachman test (100-N anteroposterior) and 2 pivot-shift loadings were conducted: anterior tibial loading (100 N), valgus rotation (7 Nm), and internal rotation (5 Nm and 1 Nm). The tibia was digitized to study the resulting medial, central, and lateral tibiofemoral compartment translations. In group 1 knees, 15 bone-patellar tendon-bone reconstructions were first tested, followed by ACL graft loosening with 3- and 5-mm increases in Lachman ATT. In group 2, 43 knees underwent robotic testing before and after ACL sectioning and underwent analysis of the effect of 3- and 5-mm increases in Lachman ATT and complete ACL sectioning on pivot-shift compartment translations.

RESULTS

In group 1 knees, ACL graft loosening allowing a 3-mm increase in Lachman ATT resulted in increases in pivot-shift lateral compartment translation (lateral compartment ATT) of only 1.6 ± 0.3 mm and 2.2 ± 1.0 mm (internal rotation of 5 Nm and 1 Nm, respectively) that were one-half of those required for a positive pivot-shift test finding. In group 2, for a 3-mm increased Lachman test, there were no positive pivot-shift values. In both groups, a Lachman test with an increase in ATT of 3 mm or less (100 N) had a 100% predictive value for a negative pivot-shift test finding. With ACL graft loosening and a 5-mm increase in the Lachman ATT, group 1 still had no positive pivot-shift values, and in group 2, a positive pivot-shift test finding occurred in 3 of 43 knees (7%, pivot shift 1-Nm internal rotation). After ACL sectioning, a highly predictive correlation was found between abnormal increases in Lachman and pivot-shift translations (P < .001).

CONCLUSIONS

ACL graft slackening and an instrumented Lachman test with an increase in ATT of 3 mm or less were 100% predictive of a negative pivot-shift subluxation finding and retained ACL stability. Further graft slackening and a 5-mm increase in the Lachman ATT produced pivot-shift lateral compartment ATT increases still less than the values in the ACL-deficient state; however, 7% of the knees (3 of 43) were converted to a positive pivot-shift test finding indicative of ACL graft failure.

CLINICAL RELEVANCE

Instrumented Lachman tests provide objective data on ACL function and graft failure to supplement subjective pivot-shift tests and are highly recommended for single-center and multicenter ACL studies. In the past decade, a near majority of published ACL studies no longer reported on instrumented Lachman tests, relying solely on highly subjective pivot-shift grading by multiple examiners.

Editorial Commentary: The Pivot Shift and Lachman Examinations: Teammates With Distinct Roles

The pivot shift and Lachman examinations are "teammates" with complementary but distinct roles in the successful diagnosis and treatment of anterior cruciate ligament rupture and injury to the surrounding soft-tissue envelope of the knee. The Lachman test measures anterior tibial translation in response to an applied anterior tibial load. This test assesses the integrity of the native or reconstructed anterior cruciate ligament and the secondary medial restraints including the medial meniscus and medial collateral ligament. In contrast, the pivot shift exam creates coupled tibiofemoral motions in response to a complex combination of multiplanar loads. This test assesses the stabilizing role of the native or reconstructed anterior cruciate ligament and the secondary lateral restraints including the lateral meniscus and anterolateral complex. The pivot shift grade depends not only on the soft the tissue stabilizers of the knee but also on the shape of the proximal tibia and the distal femur including lateral tibial slope and femoral condylar offset. Both examinations have unique strengths and weaknesses, but when combined as diagnostic tools, they achieve far more collectively than what each can achieve alone.

Knee laxity, lateral meniscus tear and distal femur morphology influence pivot shift test grade in ACL injury patients

PURPOSE

Although several factors have been considered to be associated with pivot shift test grade in ACL injured patients, a conclusion regarding which factors contribute to the pivot shift test grade has not been reached. The purpose of this study was to identify factors associated with preoperative pivot shift test grade.

METHODS

Three hundred and sixty-six consecutive patients who underwent ACL reconstruction in our hospital were enrolled in the study. Patients were divided into two groups on the basis of preoperative pivot shift test grade (Mild: grade 0-3, Severe: grade 4-6). First, 13 independent variables (age, gender, period from injury to surgery, hyperextension, KT measurement, contralateral side pivot shift test grade, medial and lateral tibial slope, lateral condyle length, lateral condyle height, distal femoral condyle offset, medial and lateral meniscus tear) were analyzed by one-way ANOVA and Chi-squared test. Binary Logistic regression was then performed based on the results of univariate analyses (independent variables of p < 0.2 were included).

RESULTS

Hyperextension, lateral meniscus tear, contralateral side pivot shift test grade, distal femoral condyle offset and KT measurement were identified as risk factors for preoperative pivot shift grade via logistic regression analysis.

CONCLUSION

The current study revealed that hyperextension, lateral meniscus tear, contralateral side pivot shift test grade, distal femoral condyle offset and anterior instability were associated with preoperative pivot shift grade. Patients with above factors that cannot be modified during surgery may need special consideration when ACL reconstruction is performed, as greater preoperative pivot shift has been proven to be a risk factor for residual pivot shift after ACL reconstruction.

LEVEL OF EVIDENCE

III.

Anterior Cruciate and Anterolateral Ligament Reconstruction Using Hamstring and Peroneus Longus Tendons: Surgical Technique Description

The main objective of this study is to describe a surgical technique that combines intra- and extra-articular techniques using the semitendinosus, gracilis, and peroneus longus to perform reconstruction of the anterior cruciate ligament and anterolateral ligament. This technique offers a more stable, fast, low-cost, and widely accessible procedure and consists of drilling 3 tunnels-1 femoral and 2 tibial tunnels-in which the grafts are fixed with interference screws. The fact that the peroneus longus graft is long and thick allows for robust reconstruction of the aforementioned ligaments.

Truly Existing or Hyped up? Unravelling the Current Knowledge Regarding the Anatomy, Radiology, Histology and Biomechanics of the Enigmatic Anterolateral Ligament of the Knee Joint

Ever since its description, anterolateral ligament (ALL) of the knee joint remains as the hotspot of controversies. Though it has been described under various descriptions, the structure gained its limelight when it was christened as anterolateral ligament by Claes in 2013. The main reason for the controversies around it is the lack of concrete evidences regarding its attachments, morphology, biomechanical aspects and radiological appearance. Similarly the role of ALL in pivot shift phenomenon also remains as a point of debate. The advocates of ALL suggest that because of its ability to modulate internal rotation and attachment to the lateral meniscus, ALL contributes to the pivot shift phenomenon. Similarly, the orientation of ALL stands as the reason for varied documentation with respect to imaging techniques. With the growing body of evidence, it is imperative to fix our stand regarding the structure because, if found to be morphologically persistent, it can be used for concomitant anterolateral stabilization along with anterior cruciate ligament reinforcement surgeries. The present review tries to systematically review the anatomy, variations in classifications, descriptions, histology, radiology and biomechanical features of ALL. At the end of the review, we would like to find the answer for the question: Is ALL a distinct ligamentous structure located at the anterolateral aspect of the knee? What is the contribution of it to the tibial internal rotation stability?

Risk Factors for Grade 3 Pivot Shift in Knees With Acute Anterior Cruciate Ligament Injuries: A Comprehensive Evaluation of the Importance of Osseous and Soft Tissue Parameters From the SANTI Study Group

BACKGROUND

Preoperative grade 3 pivot shift has been reported to be associated with higher rates of anterior cruciate ligament (ACL) failure, persistent instability, and inferior patient-reported outcomes. The etiology of a high-grade pivot shift is multifactorial, and numerous factors have been suggested to be responsible. More attention has recently been focused on injury to the anterolateral structures (ALS) as a risk factor for a grade 3 pivot shift.

PURPOSE

To determine risk factors for grade 3 pivot shift, including soft tissue and osseous parameters.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A prospective evaluation was undertaken of 200 consecutive patients undergoing acute ACL reconstruction (within 10 days of injury). An open exploration of the lateral side of the injured knee was performed at the time of the index procedure. Details regarding patient and injury characteristics were recorded, as were details of soft tissue injuries, including meniscal tears, ALS lesions, medial collateral ligament tears, and chondral injuries. Osseous parameters (tibial slope and condylar ratios) were determined per established magnetic resonance imaging protocols. A multivariate logistic regression with penalized maximum likelihood was used to identify risk factors associated with International Knee Documentation Committee (IKDC) grade 3 pivot shift.

RESULTS

The mean ± SD age of the population was 28.3 ± 9.8 years; 67.5% of patients were male. Among patients, 35 (17.5%) had a high-grade pivot shift (IKDC grade 3), and 165 (82.5%) had a low-grade pivot shift (IKDC grades 1 and 2). Univariate and multivariate logistic regression analysis demonstrated that injury to the ALS was the only significant risk factor for grade 3 pivot shift (odds ratio, 13.49; 95% CI, 1.80-1725.53).

CONCLUSION

This comprehensive evaluation of soft tissue and osseous factors has identified that injury to the ALS is the most important risk factor for grade 3 pivot shift in acute ACL-injured knees.

Painful Palpation of the Tibial Insertion of the Anterolateral Ligament Is Concordant With Acute Anterolateral Ligament Injury

Background

The anterolateral ligament (ALL) has been shown to contribute to the rotational stability of the knee. However, no clinical sign specific to ALL injury has been described.

Purpose/Hypothesis

The primary aim of this study was to determine the concordance between pain elicited upon ALL palpation and ALL injury diagnosed by ultrasonography (US). The secondary aim was to look for a relationship between ALL injury and high-grade pivot shift. We hypothesized that an ALL lesion can be diagnosed clinically in an acute knee injury by palpating its tibial insertion.

Study Design

Cohort study (diagnosis); Level of evidence, 2.

Methods

A total of 130 patients (89 men, 41 women; mean age, 27.2 ± 8.3 years) with an acute, isolated anterior cruciate ligament injury who were scheduled for ligament reconstruction were enrolled in this study. ALL palpation was carried out a mean 8.8 ± 3.2 days after injury. Preoperatively, ALL integrity was evaluated with US, and the pivot shift was determined under general anesthesia. The agreement between pain upon ALL palpation and ALL injury detected on US was determined by calculating the intraclass correlation coefficient (ICC), along with 95% CIs.

Results

Distal palpation of the ALL tibial insertion elicited pain in 67 (51.5%) patients, and upon US the ALL was found to be damaged in 64 (49.2%) patients. The agreement between pain over the ALL tibial insertion and the ALL being damaged on US was excellent (ICC, 0.801; 95% CI, 0.730-0.855). Moreover, the clinical test had excellent sensitivity (92%; 95% CI, 88%-97%) and specificity (88%; 95% CI, 82%-93%). The agreement between pain at the ALL distal insertion and the pivot shift was good (ICC, 0.654; 95% CI, 0.543-0.742), and ALL palpation had excellent diagnostic accuracy for identifying rotational instability (sensitivity, 88% [95% CI, 82%-93%]; specificity, 97% [95% CI, 94%-100%]).

Conclusion

Palpation of the ALL tibial insertion highly correlates with ultrasonographic evidence of an ALL injury in the context of an acute knee injury. This simple test should become part of our standard examination when evaluating patients with acute knee injuries.

Patient-Reported and Quantitative Outcomes of Anatomic Anterior Cruciate Ligament Reconstruction With Hamstring Tendon Autografts

Background:

The pivot-shift test has become more consistent and reliable and is a meaningful outcome measurement after anterior cruciate ligament reconstruction (ACLR).

Purpose/Hypothesis:

The purpose of this investigation was to assess patient-reported outcomes (PROs) and the quantitative pivot shift (QPS) preoperatively, at time zero immediately after anatomic ACLR, and after 24 months as well as the relationship between PROs and the QPS. It was hypothesized that anatomic ACLR would restore rotatory stability measured by the pivot-shift test and that QPS measurements would be positively correlated with PROs.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

The ACL-injured and contralateral uninjured knees from 89 of 107 (83.2%) enrolled patients at 4 international centers were evaluated using a standardized pivot-shift test. Tibial acceleration was assessed with an inertial sensor, and lateral compartment translation was measured using an image analysis system preoperatively, at time zero immediately postoperatively, and at follow-up after 2 years. PROs were assessed at 12 and 24 months postoperatively with the International Knee Documentation Committee (IKDC) subjective knee form, Cincinnati Knee Rating System (CKRS), Marx activity rating scale, and activity of daily living score (ADLS).

Results:

The mean patient age at surgery was 27 years (range, 15-45 years). A positive pivot shift preoperatively (side-to-side difference in tibial acceleration, 2.6 ± 4.0 m/s²; side-to-side difference in anterior tibial translation, 2.0 ± 2.0 mm) was reduced at time zero postoperatively (side-to-side difference in tibial acceleration, –0.5 ± 1.3 m/s²; side-to-side difference in anterior tibial translation, –0.1 ± 1.0 mm). All PROs improved from preoperatively to final follow-up at 24 months: from 56.5 to 85.5 points for the IKDC (P = .0001), from 28.8 to 32.4 points for the CKRS (P = .04), from 11.2 to 7.9 points for the Marx (P < .0001), and from 75.7 to 91.6 points for the ADLS (P < .0001). Neither preoperative nor time zero postoperative rotatory laxity assessed by the pivot-shift test correlated with PROs at 24-month follow-up. A graft retear was observed in 4 patients (4.5%) within 2 years of follow-up.

Conclusion:

Anatomic ACLR resulted in significantly improved and acceptable PROs at 2-year follow-up and a low failure rate. Anatomic ACLR restored QPS measurements of anterior tibial translation and tibial acceleration to those of the contralateral knee immediately after surgery while still under anesthesia, but there was no correlation between the QPS preoperatively or at time zero after ACLR and PROs at 2-year follow-up.

High-Grade Posterolateral Tibial Plateau Impaction Fractures in the Setting of a Primary Anterior Cruciate Ligament Tear Are Correlated With an Increased Preoperative Pivot Shift and Inferior Postoperative Outcomes After Anterior Cruciate Ligament Reconstruction

BACKGROUND

Impaction fractures of the posterolateral tibial plateau have been previously described to occur in association with anterior cruciate ligament (ACL) tears; however, the effect of these injuries on patient-reported outcomes (PROs) after ACL reconstruction (ACLR) is not well known.

PURPOSE

(1) To assess the effect of posterolateral tibial plateau impaction fractures on preoperative clinical knee stability assessed by the Lachman and pivot-shift examinations and (2) to assess the effect of impaction fractures on PROs after ACLR.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients undergoing ACLR for primary ACL tears with available magnetic resonance imaging (MRI) scans were included in this study. MRI scans were reviewed for the presence of posterolateral tibial plateau impaction fractures, which were classified according to the morphological variant. Associations with clinical laxity determined by an examination under anesthesia were assessed using binary logistic regression. Also, 2-year postoperative PROs (12-Item Short Form Health Survey [SF-12] Mental Component Scale and Physical Component Scale [PCS], Lysholm, Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], and Tegner scores) were modeled using multiple ordinal logistic regression to assess the effect of posterolateral tibial plateau impaction fracture classification while adjusting for other covariates. Pearson correlation coefficients (PCCs) were used to assess for correlations between postoperative PROs and the amount of tibial plateau bone loss present.

RESULTS

Displaced posterolateral tibial plateau impaction fractures were present in 407 (49.3%) of 825 total knees included in this study. Knees with type IIIB impaction fractures had an increased likelihood of having a high-grade pivot shift (odds ratio, 2.3; P = .047), with no other impaction fracture types showing a significant association. There were no significant associations between posterolateral tibial plateau impaction fracture type and a higher Lachman grade. Of the 599 eligible knees with 2-year follow-up, postoperative information was obtained for 419 (70.0%). Patients improved in all PROs at a mean of 3.0 years after ACLR (P < .001). Multiple ordinal logistic regression demonstrated a posterolateral tibial plateau impaction fracture as an independent predictor of the postoperative Lysholm score, with higher grade impaction fractures showing decreased Lysholm scores. Pearson correlation testing demonstrated weak but statistically significant correlations between sagittal bone loss of posterolateral tibial plateau impaction fractures and SF-12 PCS (PCC = -0.156; P = .023), WOMAC total (PCC = 0.159; P = .02), Lysholm (PCC = -0.203; P = .003), and Tegner scores (PCC = -0.151; P = .032).

CONCLUSION

When classified into distinct morphological subtypes, high-grade posterolateral tibial plateau impaction fractures were independently associated with decreased postoperative outcomes after ACLR when controlling for other demographic or clinical variables. Patients with large depression-type posterolateral tibial plateau impaction fractures (type IIIB) had an increased likelihood of having high-grade pivot-shift laxity on clinical examination under anesthesia.

Comparative clinical outcomes of anterolateral ligament reconstruction versus lateral extra-articular tenodesis in combination with anterior cruciate ligament reconstruction: systematic review and meta-analysis

BACKGROUND

Anterolateral augmentation procedures can be divided into traditional lateral extra-articular tenodesis (LET) and modern anterolateral ligament (ALL) reconstruction. Nevertheless, no studies have compared the clinical results between LET and ALL reconstruction, when combined with intra-articular ACL reconstruction. This study was therefore designed to compare the clinical results, including the anterior translation, rotational laxity, and patient-reported outcomes, in a group of patients who underwent ACL reconstruction combined with LET or ALL reconstruction.

METHODS

All studies systematically searched until March 2018 without any language restriction that reported the results of a lateral extra-articular stabilization procedure using either LET or ALL reconstruction methods combined with ACL reconstruction were evaluated. Two reviewers independently recorded data from each study, including the sample size, improvement in Lysholm score, and the number of patients with each grade of knee laxity using Lachman and pivot shift tests.

RESULTS

The pooled results of ten studies showed that the postoperative proportion of knees with grade 2 or 3 on the Lachman test was significantly higher following LET compared with ALL reconstruction in combination with ACL reconstruction (10.8%, 95% confidence interval [CI]: 6.6-17.1% vs. 1.5%, 95% CI 0.5-4.5%; p = 0.001). However, the pooled results of 12 studies showed that the proportion of knees that belonged to grade 2 or 3 on the pivot shift test, indicating poor rotational stability, was similar between these two techniques (4.9%, 95% CI 2.0-11.5% vs. 2.3%, 95% CI 1.1-4.5%; p = 0.101). The pooled improvements in Lysholm scores in these two groups were also similar (32.3, 95% CI 26.8-37.9 vs. 25.7, 95% CI 16.7-34.7, p = 0.218).

CONCLUSION

LET could lead to worse anterior instability than with ALL reconstruction when these two approaches were combined with single-bundle ACL reconstruction. However, rotational stability and patient-reported outcomes were similar between the techniques.

Radiological Identification of Injury to the Kaplan Fibers of the Iliotibial Band in Association With Anterior Cruciate Ligament Injury

BACKGROUND

Recent biomechanical studies have demonstrated that the Kaplan fibers (KFs) of the iliotibial band play a role in the control of anterolateral rotation of the knee. However, controversy exists regarding whether the KFs are injured in conjunction with anterior cruciate ligament (ACL) injury.

PURPOSE

To establish the prevalence of radiological injury to the KFs in the ACL-injured knee; to evaluate the effect of the time interval between injury and magnetic resonance imaging (MRI) on diagnosis of KF injury; and to assess for any association between KF injury and other qualitative radiological findings.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 3.

METHODS

Preoperative MRI scans were reviewed for 161 patients with ACL injury. Specific diagnostic criteria were developed and applied to identify KF injury. Chi-square testing was performed to look for associations among KF injury, the time from injury to MRI, and associated radiological knee injuries.

RESULTS

Radiological evidence of KF injury was identified in 30 (18.6%) patients. The diagnosis of KF injury was higher in patients who had MRI scans performed within 90 days of injury as compared with ≥90 days after injury (23.7 vs 6.4%; P = .010). Patients with an MRI diagnosis of KF injury had significantly higher rates of lateral meniscal injury (40% vs 18%; P = .007), posteromedial tibial bone marrow edema (73% vs 44%; P = .003), and injury to the lateral collateral ligament (13% vs 3%; P = .019) or medial collateral ligament (23% vs 8%; P = .019).

CONCLUSION

The prevalence of injury to the KF in patients with ACL injury as diagnosed by MRI was relatively low (18.6% of patients). However, the time interval from injury to MRI was relevant to diagnosis, with significantly higher rates of injury identification in patients with early (within 90 days) versus delayed (≥90 days) MRI. KF injury was associated with higher rates of injury to the lateral meniscal and collateral ligaments, as well as posteromedial tibial bone bruising.

Visualization of Proximal and Distal Kaplan Fibers Using 3-Dimensional Magnetic Resonance Imaging and Anatomic Dissection

BACKGROUND

In current magnetic resonance imaging (MRI) of the knee, injuries to the anterolateral ligament complex (ALC) and the Kaplan fibers (KFs) are not routinely assessed. As ruptures of the KFs contribute to anterolateral rotatory instability in the anterior cruciate ligament-deficient knee, detecting these injuries on MRI may help surgeons to individualize treatment.

PURPOSE

To visualize the KFs on 3-T MRI and to conduct a layer-by-layer dissection of the ALC.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Ten fresh-frozen human cadaveric knees (mean ± SD age, 72 ± 8.5 years) without history of ligament injury were used in this study. Before layer-by-layer dissection of the ALC, MRI was performed to define the radiologic anatomy of the KFs. A coronal T1-weighted 3-dimensional turbo spin echo sequence and a transverse T2-weighted turbo spin echo sequence were obtained. Three-dimensional data sets were used for multiplanar reconstructions.

RESULTS

KFs were identified in 100% of cases on MRI and in anatomic dissection. The mean length of the proximal and distal KFs was 17.9 ± 3.6 mm and 12.4 ± 6.5 mm, respectively. On MRI, the distance from the lateral femoral epicondyle to the proximal KFs was 35.9 ± 6.9 mm and to the distal KFs, 16.6 ± 4.1 mm; in anatomic dissection, the distances were 41.4 ± 8.1 mm for proximal KFs and 28.2 ± 8.1 mm for distal KFs. The distance from the lateral joint line to the proximal KFs was 63.5 ± 7.6 mm and to the distal KFs, 45.3 ± 3.7 mm. Interobserver reliability for image analysis was excellent for all measurements.

CONCLUSION

KFs can be consistently identified on MRI with use of 3-dimensional sequences. Subsequent anatomic dissection confirmed their close topography to the superior lateral genicular artery. For clinical implications, the integrity of the KFs should be routinely reviewed on MRI scans.

CLINICAL RELEVANCE

As ruptures of the KFs contribute to anterolateral rotatory instability, accurate visualization of the KFs on MRI may facilitate surgical decision making for additional anterolateral procedures in the anterior cruciate ligament-deficient knee.

Ramp lesions of the medial meniscus are associated with a higher grade of dynamic rotatory laxity in ACL-injured patients in comparison to patients with an isolated injury

PURPOSE

The purpose of this study was to compare preoperative knee laxity between two groups of patients with primary or revision ACL reconstruction with or without an associated ramp lesion of the medial meniscus.

METHODS

Two-hundred and seventy-five patients with an ACL reconstruction (243 primaries; 32 revisions) were prospectively screened using direct arthroscopic visualisation and divided into a ramp lesion group (RLG) and a control group (CG) regardless of the presence of other associated meniscal tears. All patients were clinically examined under anaesthesia before surgery by grading the Lachman and pivot shift tests.

RESULTS

Fifty-eight patients were included in the RLG. The CG included 217 patients. With all meniscus lesions included, there were no significant differences between the two groups. After excluding all other meniscus lesions in both groups except for ramp lesions in the RLG, the prevalence of a grade III pivot shift was higher in the RLG (32 remaining patients; 47% grade III) compared to the CG (91 remaining patients; 24% grade III, p = 0.02). The difference of patients with a grade III pivot shift between the CG and RLG remained significant after removal of revision ACL reconstructions (CG, 85 remaining patients; 25% grade III-RLG, 27 remaining patients; 44% grade III, p = 0.05).

CONCLUSION

Patients with an isolated ramp lesion of the medial meniscus in association with an ACL injury displayed a higher amount of dynamic rotational laxity as expressed by the pivot shift test in comparison to patients with isolated ACL injury and no ramp lesion. The association between ramp lesions of the medial meniscus and increased pivot shift grading suggests that it is important to diagnose and repair them during ACL reconstruction surgery.

LEVEL OF EVIDENCE

III.

Excessive Preoperative Anterior Tibial Subluxation in Extension Is Associated With Inferior Knee Stability After Anatomic Anterior Cruciate Ligament Reconstruction

BACKGROUND

Anterior tibial subluxation (ATS) in extension after anterior cruciate ligament (ACL) injury highlights an increased anterior position of the tibia relative to the femur. Recent studies demonstrated that subluxation is sometimes irreducible and the normal tibiofemoral relationship is not restored by ACL reconstruction (ACLR), which raises concerns regarding clinical outcomes after ACLR.

HYPOTHESIS

Excessive preoperative ATS in extension is associated with inferior knee stability after anatomic ACLR.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

From March 2016 to January 2017, a total of 487 consecutive patients with clinically diagnosed noncontact ACL injuries who underwent primary anatomic ACLR were retrospectively analyzed. Of these patients, 430 met the criteria for inclusion in this study. Anterior subluxation of the lateral and medial compartments (ASLC and ASMC) in extension relative to the femoral condyles was measured on preoperative magnetic resonance imaging. Twenty patients (study group) who demonstrated excessive (>10 mm) ASLC and ASMC in extension were matched 1:2 to 40 participants (control group) who showed minimal or no (<3 mm) ASLC and ASMC in extension. The amount of ASLC and ASMC in extension relative to the femoral condyles at 2 years postoperatively was the primary outcome. Moreover, the Lysholm score, IKDC grade (International Knee Documentation Committee), and stability assessments (pivot-shift test and KT-1000 arthrometer side-to-side difference) were evaluated preoperatively and at the last follow-up visit.

RESULTS

The preoperative mean ASLC and ASMC in extension of the study group were both significantly larger than those of the control group (study group vs control group: ASLC, 13.5 mm vs 1.2 mm; ASMC, 12.4 mm vs 1.0 mm; P < .05). Moreover, patients in the study group showed significantly larger posterior tibial slope than the patients in the control group (17.8°± 2.5° vs 9.5°± 1.5°; P < .05). At the final follow-up visit, the mean ASLC and ASMC of the study group were 8.1 mm and 7.3 mm, which were significantly larger than those of the control group (ASLC, 0.9 mm; ASMC, 0.7 mm; P < .05). In addition, the study group showed inferior knee stability when compared with the control group in terms of both the pivot-shift test (study group vs control group: 2 grade 2, 10 grade 1, and 8 grade 0 vs 1 grade 1 and 39 grade 0; P < .05) and the KT-1000 arthrometer side-to-side difference (study group vs control group: 4.4 ± 1.2 mm vs 1.5 ± 0.6 mm; P < .05). Furthermore, the study group showed significantly lower mean Lysholm score (study group vs control group: 80.3 ± 6.3 vs 93.3 ± 4.3, P < .05) and IKDC grading results (study group vs control group: 3 grade C, 16 grade B, and 1 grade A vs 3 grade B and 37 grade A; P < .05) as compared with the control group.

CONCLUSION

In this short-term study, the excessive (>10 mm) preoperative ATS in extension after ACL injury was associated with inferior knee stability after anatomic ACLR.

Incidence of Displaced Posterolateral Tibial Plateau and Lateral Femoral Condyle Impaction Fractures in the Setting of Primary Anterior Cruciate Ligament Tear

BACKGROUND

Bone bruising of the posterolateral tibial plateau and the lateral femoral condyle sulcus terminalis has a well-established association with anterior cruciate ligament (ACL) tears. Impaction fractures of the femur and tibia may occur in these locations; however, there is a paucity of literature describing these fractures.

PURPOSE

The primary objective was to quantify the incidence, size, and location of impaction fractures of the posterolateral tibial plateau and lateral femoral condyle in patients with primary ACL tears. The secondary objective was to investigate the association between impaction fractures and concomitant meniscal and ligamentous injuries.

STUDY DESIGN

Case series; Level of evidence 4.

METHODS

Patients with available magnetic resonance imaging (MRI) scans who were treated for primary ACL tear by a single surgeon were identified. MRI scans were reviewed with denotation of posterolateral tibial and femoral condylar contusions and displaced impaction fractures. Measurements of the lateral tibial plateau were taken in all patients with displaced lateral tibial plateau fractures and in a subset of control patients without tibial plateau fracture present to characterize the size and location of the bony lesion. Associations of impaction fractures with concomitant meniscal or ligamentous injuries were evaluated through use of chi-square testing.

RESULTS

There were 825 knees identified with available MRI scans. Lateral tibial plateau bone bruising was present in 634 knees (76.8%), and lateral femoral condyle bone bruising was present in 407 knees (49.3%). Posterolateral tibial plateau impaction fractures were present in 407 knees (49.3%), and lateral femoral condylar impaction fractures were present in 214 knees (25.9%). Patients with posterolateral tibial plateau impaction fractures were older than patients without these fractures (42.6 vs 32.7 years; P < .001), whereas patients with lateral femoral condylar impaction fractures were younger (23.8 vs 32.7 years; P < .001). There were 71 knees (8.6%) with a posterolateral tibial plateau impaction fracture with greater than 10% loss of lateral tibial plateau depth, and this group had an increased incidence of lateral meniscus posterior root tears (22.1% vs 12.0%; P = .02).

CONCLUSION

Posterolateral tibial plateau impaction fractures occurred with a high incidence (49.3%) in patients with primary ACL tears and demonstrated an increased association with lateral meniscus posterior horn root tears as their size increased. Lateral femoral condylar impaction fractures occurred in 25.9% of patients with primary ACL tears and entailed an increased incidence of lateral meniscal tears and medial meniscal ramp lesions.

Rotatory Knee Laxity Exists on a Continuum in Anterior Cruciate Ligament Injury

BACKGROUND

The purpose of this investigation was to compare the magnitude of rotatory knee laxity in patients with a partial anterior cruciate ligament (ACL) tear, those with a complete ACL tear, and those who had undergone a failed ACL reconstruction. It was hypothesized that rotatory knee laxity would increase with increasing injury grade, with knees with partial ACL tears demonstrating the lowest rotatory laxity and knees that had undergone failed ACL reconstruction demonstrating the highest rotatory laxity.

METHODS

A prospective multicenter study cohort of 354 patients who had undergone ACL reconstruction between 2012 and 2018 was examined. All patients had both injured and contralateral healthy knees evaluated using standardized, preoperative quantitative pivot shift testing, determined by a validated, image-based tablet software application and a surface-mounted accelerometer. Quantitative pivot shift was compared with the contralateral healthy knee in 20 patients with partial ACL tears, 257 patients with complete ACL tears, and 27 patients who had undergone a failed ACL reconstruction. Comparisons were made using 1-way analysis of variance (ANOVA) with post hoc 2-sample t tests with Bonferroni correction. Significance was set at p < 0.05.

RESULTS

There were stepwise increases in side-to-side differences in quantitative pivot shift in terms of lateral knee compartment translation for patients with partial ACL tears (mean [and standard deviation], 1.4 ± 1.5 mm), those with complete ACL tears (2.5 ± 2.1 mm), and those who had undergone failed ACL reconstruction (3.3 ± 1.9 mm) (p = 0.01) and increases in terms of lateral compartment acceleration for patients with partial ACL tears (0.7 ± 1.4 m/s), those with complete ACL tears (2.3 ± 3.1 m/s), and those who had undergone failed ACL reconstruction (2.4 ± 5.5 m/s) (p = 0.01). A significant difference in lateral knee compartment translation was found when comparing patients with partial ACL tears and those with complete ACL tears (1.2 ± 2.1 mm [95% confidence interval (CI), 0.2 to 2.1 mm]; p = 0.02) and patients with partial ACL tears and those who had undergone failed ACL reconstruction (1.9 ± 1.7 mm [95% CI, 0.8 to 2.9 mm]; p = 0.001), but not when comparing patients with complete ACL tears and those who had undergone failed ACL reconstruction (0.8 ± 2.1 [95% CI, -0.1 to 1.6 mm]; p = 0.09). Increased lateral compartment acceleration was found when comparing patients with partial ACL tears and those with complete ACL tears (1.5 ± 3.0 m/s [95% CI, 0.8 to 2.3 m/s]; p = 0.0002), but not when comparing patients with complete ACL tears and those who had undergone failed ACL reconstruction (0.1 ± 3.4 m/s [95% CI, -2.2 to 2.4 m/s]; p = 0.93) or patients with partial ACL tears and those who had undergone failed ACL reconstruction (1.7 ± 4.2 m/s [95% CI, -0.7 to 4.0 m/s]; p = 0.16). An increasing lateral compartment translation of the contralateral, ACL-healthy knee was found in patients with partial ACL tears (0.8 mm), those with complete ACL tears (1.2 mm), and those who had undergone failed ACL reconstruction (1.7 mm) (p < 0.05).

CONCLUSIONS

A progressive increase in rotatory knee laxity, defined by side-to-side differences in quantitative pivot shift, was observed in patients with partial ACL tears, those with complete ACL tears, and those who had undergone failed ACL reconstruction. These results may be helpful when assessing outcomes and considering indications for the management of high-grade rotatory knee laxity.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Anterior Cruciate Ligament Reconstruction in High School and College-Aged Athletes: Does Autograft Choice Influence Anterior Cruciate Ligament Revision Rates?

BACKGROUND

Physicians' and patients' decision-making process between bone-patellar tendon-bone (BTB) and hamstring tendon autografts for anterior cruciate ligament (ACL) reconstruction (ACLR) may be influenced by a variety of factors in the young, active athlete.

PURPOSE

To determine the incidence of both ACL graft revisions and contralateral ACL tears resulting in subsequent ACLR in a cohort of high school- and college-aged athletes who initially underwent primary ACLR with either a BTB or a hamstring autograft.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Study inclusion criteria were patients aged 14 to 22 years who were injured in sports, had a contralateral normal knee, and were scheduled to undergo unilateral primary ACLR with either a BTB or a hamstring autograft. All patients were prospectively followed for 6 years to determine whether any subsequent ACLR was performed in either knee after their initial ACLR. Multivariable regression modeling controlled for age, sex, ethnicity/race, body mass index, sport and competition level, baseline activity level, knee laxity, and graft type. The 6-year outcomes were the incidence of subsequent ACLR in either knee.

RESULTS

A total of 839 patients were eligible, of which 770 (92%) had 6-year follow-up for the primary outcome measure of the incidence of subsequent ACLR. The median age was 17 years, with 48% female, and the distribution of BTB and hamstring grafts was 492 (64%) and 278 (36%), respectively. The incidence of subsequent ACLR at 6 years was 9.2% in the ipsilateral knee, 11.2% in the contralateral normal knee, and 19.7% for either knee. High-grade preoperative knee laxity (odds ratio [OR], 2.4 [95% confidence interval [CI], 1.4-3.9]; P = .001), autograft type (OR, 2.1 [95% CI, 1.3-3.5]; P = .004), and age (OR, 0.8 [95% CI, 0.7-1.0]; P = .009) were the 3 most influential predictors of ACL graft revision in the ipsilateral knee. The odds of ACL graft revision were 2.1 times higher for patients receiving a hamstring autograft than patients receiving a BTB autograft (95% CI, 1.3-3.5; P = .004). No significant differences were found between autograft choices when looking at the incidence of subsequent ACLR in the contralateral knee.

CONCLUSION

There was a high incidence of both ACL graft revisions and contralateral normal ACL tears resulting in subsequent ACLR in this young athletic cohort. The incidence of ACL graft revision at 6 years after index surgery was 2.1 times higher with a hamstring autograft compared with a BTB autograft.

Inter-rater reliability of an ultrasound protocol to evaluate the anterolateral ligament of the knee

Objectives: The aim of this study was to validate an ultrasound protocol for evaluating the anterolateral ligament of the knee. Methods: A Thiel technique cadaveric specimen was used to validate an optimal scanning position and develop an ultrasound protocol to evaluate the anterolateral ligament. Three musculoskeletal sonographers acquired short- and long-axis images of the anterolateral ligament in 36 knees from 18 healthy volunteers. Anterolateral ligament length, thickness, width, and distance between anterolateral ligament insertion and lateral tibia plateau were measured. Intraclass Correlation Coefficient (ICC) was calculated. Results: The inter-rater reliability for anterolateral ligament thickness was poor, ICC = 0.35 (95% CI: –0.06–0.63). The inter-rater reliability for anterolateral ligament length and width was good, ICC = 0.80 (95% CI 0.64–0.89), ICC = 0.88 (95% CI 0.79–0.94), respectively; and the inter-rater reliability for the distance between insertion and lateral tibia plateau was excellent, ICC = 0.96 (95% CI 0.93–0.98). Conclusions: Ultrasonography is a reliable method for evaluating the anterolateral ligament. There is an excellent reliability for the distal part of the anterolateral ligament. As injuries usually occur in this part of the ligament, this protocol may be used to evaluate the anterolateral ligament in patients with suspected anterior cruciate ligament tears in clinical practice.

Biomechanical comparison of anterolateral ligament anatomical reconstruction with a semi-anatomical lateral extra-articular tenodesis. A cadaveric study

BACKGROUND

To compare the biomechanical behavior of an anterolateral ligament (ALL) anatomical reconstruction and a semianatomical lateral extra-articular tenodesis (LET) in the context of an anterior cruciate ligament (ACL) reconstruction combined with an anterolateral lesion.

METHODS

Twelve cadaveric knees were studied using a testing machine to assess the internal tibial rotation and anterior tibial translation across six surgical states: intact knee, ACL lesion, ACL + ALL lesion, ACL isolated reconstruction, ACL + ALL anatomical reconstruction and ACL + LET procedure. ALL and LET grafts were fixed at full knee extension and neutral rotation.

RESULTS

Presented with combined ACL and ALL lesions, isolated ACL reconstruction failed to restore the internal tibial rotation to intact-knee values (P > 0.05 for all angles). The addition of both an ALL reconstruction and LET procedure significantly reduced the internal rotation, restoring the rotation laxity to intact-knee values at 0° and 30° of flexion (P < 0.05) and with a certain level of overconstraint at 60° and 90° (mean 3° ± 2SD). A higher tendency to overconstraint was observed with the LET, but there was no significant difference when comparing the ALL reconstruction with the LET (P > 0.05 for all angles).

CONCLUSIONS

Residual rotational laxity was found after isolated ACL reconstruction in the presence of an anterolateral lesion. The combination of ACL reconstruction with anatomical ALL reconstruction or the LET procedure resulted in restoration to intact-knee values but with a certain degree of overconstraint in higher flexion angles. Both techniques showed optimal biomechanical results with no data supporting the advantage of one over the other.

EXTRA-ARTICULAR RECONSTRUCTION ASSOCIATED WITH THE ANTERIOR CRUCIATE LIGAMENT IN BRAZIL

OBJECTIVE

To assess the knowledge and technical preferences of Brazilian knee surgeons in relation to the treatment of Anterior Cruciate Ligament (ACL) injuries using intra-articular reconstruction in combination with extra-articular reconstruction.

METHODS

A questionnaire consisting of 16 questions about intra-articular ACL reconstruction in combination with extra-articular procedures and about the Anterolateral Ligament (ALL) was applied at the 48^th Brazilian Congress of Orthopedics.

RESULTS

One hundred thirty-seven surgeons answered the questionnaire. Most surgeons perform 10-30 ACL reconstructions per year, with the transtibial technique appearing as the most common. Most surgeons find some percentage of residual pivot-shift after reconstructions, but the minority performs extra-articular procedures on a routine basis. The main indications for extra-articular reconstruction are revision and profuse pivot-shift cases. Most surgeons consider the ALL a true ligament, but 46.7% with less biomechanical importance and 32.3% with greater importance in knee stability. However, 91.4% had a positive perception of the reconstruction of this structure.

CONCLUSION

Although the preferred technique is still the transtibial procedure, combined anatomical reconstructions already make up more than 50% of cases. Extra-articular reconstructions associated with the ACL are still performed by the minority of Brazilian surgeons, but 91.4% of them report having had a positive perception with their reconstruction. Level of Evidence III, Descriptive Study.

Distal femur morphology affects rotatory knee instability in patients with anterior cruciate ligament ruptures

PURPOSE

Distal femur morphology has been shown to influence knee joint kinematics and may affect rotatory knee laxity. The purpose of this study was to determine the relationship between rotatory knee laxity and distal femoral morphology in patients with complete anterior cruciate ligament (ACL) rupture. It was hypothesized that increased posterior femoral condylar depth on standard lateral radiographs, quantified as the "lateral femoral condyle ratio" would correlate with increased rotatory knee laxity, measured by a quantitative pivot shift test.

METHODS

Consecutive patients who underwent ACL reconstruction from 2014 to 2016 were retrospectively reviewed. A standardized pivot shift test was performed preoperatively on both knees and quantified using tablet technology. Using standard lateral radiographs of the knee, the ratio of posterior condylar distance over total condylar distance was defined as the lateral femoral condyle ratio.

RESULTS

Data sets were obtained for 57 patients. The mean anterior translation of the lateral knee compartment during a quantitative pivot shift test was found to be 4.0 ± 2.4 mm and 1.3 ± 0.9 mm for the injured and uninjured knees, respectively. The mean lateral femoral condyle ratio on X-ray was 63.2 ± 4.5%. There were significant correlations between the lateral femoral condyle ratio and the absolute quantitative (ρ = 0.370, p < 0.05) and side-to-side differences in anterior translation of the lateral knee compartment (ρ = 0.419, p < 0.05).

CONCLUSION

The most important finding from this study is that increased posterior femoral condylar depth, quantified as a lateral femoral condyle ratio, is associated with increased rotatory knee laxity in ACL-deficient patients. This suggests that distal femur morphology may influence rotatory knee laxity. This study may assist clinicians in evaluating ACL injuries and identifying patients at greater risk for persistent increased rotatory knee laxity after ACL reconstruction.

LEVEL OF EVIDENCE

III.

Identification of Normal and Injured Anterolateral Ligaments of the Knee: A Systematic Review of Magnetic Resonance Imaging Studies

PURPOSE

To identify the normal and injured magnetic resonance imaging appearance of the anterolateral ligament (ALL).

METHODS

A systematic review was performed using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The PubMed and Cochrane Library electronic databases were used to search for studies that reported the imaging outcomes of the appearance of the ALL. Two authors performed the searches in duplicate up to April 30, 2018, and interobserver agreement was calculated. The methodologic quality of included articles was assessed using an adaptation of the Arrivé methodologic quality scale for clinical studies of radiologic examinations.

RESULTS

From the original 270 records, a total of 24 studies (κ = 0.94) comprising 2,427 knees in 2,388 patients (mean age, 33.3 years; 66% male patients; 63% with anterior cruciate ligament [ACL] injury) were included. The ALL appeared in 51% to 100% of all assessed knees (71%-100% in ACL-injured knees and 64%-97% in uninjured knees) and was injured in 11% to 79% of ACL-injured knees. Reliability rates varied considerably (0.04-1.0 for intraobserver and 0.143-1.0 for interobserver agreement), and the entire portion of the ligament was often not seen. The tibial insertion was seen in 21% to 96% of cases, followed by the meniscal (range, 0%-100%) and femoral (range, 0%-90%) insertions. The mean methodologic quality score was 5.1 ± 1.8 out of a possible score of 9.

CONCLUSIONS

High variability was found in the identification of normal and injured ALL definition methods and the respective magnetic resonance imaging findings. Reliability rates varied considerably, and the entire portion of the ligament was often not seen.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II to IV studies.

The concomitant lateral meniscus injury increased the pivot shift in the anterior cruciate ligament-injured knee

PURPOSE

Concomitant meniscus injuries in the anterior cruciate ligament (ACL) have been suggested to exacerbate rotational laxity. However, the effect is supposed to be so small, if any, that some quantitative pivot-shift measurement is needed. The purpose of this prospective study was to determine the effect of meniscus tear on rotational laxity in ACL-deficient knees by an quantitative measurement. It was hypothesized that a concomitant meniscus tear, especially a lateral one, would induce greater pivot shift.

METHODS

Fifty-seven unilateral ACL-injured patients (26 men and 31 women, mean age: 24 ± 10 years) were included. The pivot-shift test was performed prior to ACL reconstruction, while a quantitative evaluation using an electromagnetic system to determine tibial acceleration and a clinical grading according to the IKDC were performed. Meniscus injuries were diagnosed arthroscopically, and concomitant meniscus tear was confirmed in 32 knees.

RESULTS

The clinical grade was not different between the ACL-injured knees of patients with and without meniscus tear (n.s.). Tibial acceleration did not show a statistical significant difference (meniscus-injured knees: 1.6 ± 1.1 m/s² versus meniscus-intact knees: 1.2 ± 0.7 m/s², n.s.). However, the subgroup analysis demonstrated that there was increased tibial acceleration in ACL-deficient knees with lateral meniscus tear (2.1 ± 1.1 m/s², n = 13) compared with meniscus-intact knees (p < 0.05), whereas rotational laxity did not increase in the medial meniscus-injured and bilateral-injured knees (1.2 ± 0.9 m/s², n = 12, n.s. and 1.4 ± 1.1 m/s², n = 7, n.s., respectively).

CONCLUSION

A concomitant meniscus tear, especially a lateral meniscus tear, has a significant impact on rotational laxity in ACL-injured knees. When a large pivot shift is observed in the ACL-injured knee, a concomitant meniscus tear should be suspected and an aggressive treatment would be considered. Meniscus injuries should be inspected carefully when substantial pivot shift is encountered in ACL-injured knees.

LEVEL OF EVIDENCE

Diagnostic study, Level III.

The Pivot Shift: Current Experimental Methodology and Clinical Utility for Anterior Cruciate Ligament Rupture and Associated Injury

PURPOSE OF REVIEW

The purpose of this manuscript is to (1) examine the history, techniques, and methodology behind quantitative pivot shift investigations to date and (2) review the current status of pivot shift research for its clinical utility for management of anterior cruciate ligament (ACL) rupture with associated injuries including the anterolateral complex (ALC).

RECENT FINDINGS

The pivot shift is a useful physical exam maneuver for diagnosis of rotatory instability related to ACL tear. Recent evidence suggests that the pivot shift is multifactorial and can be seen in the presence of ACL tear with concomitant injury to secondary stabilizers or with predisposing anatomical factors. The presence of a pivot shift post-operatively is associated with poorer outcomes after ACL reconstruction. Recent clinical and biomechanical investigations can help guide clinicians in utilizing pivot shift in diagnosis and surgical planning. Further research is needed to clarify optimal management of ALC in addition to ACL injury.

Influence of anterolateral ligament injuries on stability and second-look arthroscopic findings after allograft transtibial anterior cruciate ligament reconstruction

BACKGROUND

The purpose of this study was to evaluate the influence of anterolateral ligament (ALL) injuries on stability and second-look arthroscopic findings after anterior cruciate ligament (ACL) reconstruction.

METHODS

One-hundred and nineteen consecutive patients underwent a second-look arthroscopic surgery after ACL reconstruction and magnetic resonance imaging (MRI) examination of the ALL. The patients were divided into an ALL intact group (n = 39) and ALL injured group (n = 80). The ALL injuries were divided according to the three anatomical parts of the ALL (femoral, meniscal, and tibial) using MRI evaluation. Stability and clinical results were evaluated using the Lachman test, pivot-shift test, KT-2000 arthrometer, and Lysholm score. On second-look arthroscopy, graft tension and synovial coverage were evaluated.

RESULTS

The clinical evaluation revealed no significant differences in ALL injury. Although the synovial coverages showed no significant difference (P = 0.113), the second-look arthroscopic findings indicated that tension was statistically significantly dependent on the ALL injury (P < 0.001). In addition, according to the location of the ALL injury, femoral, tibial, and combined ALL injuries showed significant differences in graft tension as compared with the ALL intact group; only the meniscal injuries had no effect on graft tension.

CONCLUSION

Combined ACL and ALL injuries showed poor graft tension in the second-look arthroscopic findings after allograft transtibial ACL reconstruction, even though no significant differences in clinical outcomes and stability were observed.