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

Comprehensive Clinical Examination of ACL Injuries

A comprehensive clinical examination of the potentially anterior cruciate ligament (ACL)-deficient knee should proceed as follows: inspection; palpation; range of motion; varus and valgus stress; neurovascular status; and finally provocative maneuvers. The Lachman, anterior drawer, Lever, and pivot shift tests are all greater than 90% specific for ACL pathology. Due to the relatively high coincidence of ACL injuries and those to the posterior cruciate ligament, posterolateral corner , posteromedial corner , and menisci, it is critical that the examiner perform provocative maneuvers to evaluate the integrity of these structures as well.

Wearable sensor systems measure differences in knee laxity between healthy and affected knees during dynamic exercise activities: A systematic review

Purpose

Knee laxity can be experienced as knee instability which may lead to a limitation in the activity of patients. Current methods to determine knee instability are performed in a static setting, which does not always correlate with dynamic knee laxity during activities. Wearables might be able to measure knee laxity in a dynamic setting and could be of added value in the diagnosis and treatment of excessive knee laxity. Therefore, the aim of this systematic review is to provide an overview of the wearables that have been developed and their ability to measure knee laxity during dynamic activities.

Methods

The PRISMA guidelines for systematic reviews were followed. A literature search was conducted in EMBASE, PubMed and Cochrane databases. Included studies assessed patients with knee instability using a non-invasive wearable sensor system during dynamic activity, with comparison to a reference system or healthy knees. Data extraction was performed by two authors via a predefined format. The risk of bias was assessed by The Dutch checklist for diagnostic tests.

Results

A total of 4734 articles were identified. Thirteen studies were included in the review. The studies showed a great variety of patients, sensor systems, reference tests, outcome measures and performed activities. Nine of the included studies were able to measure differences in patients with knee instability, all including a tri-axial accelerometer. Differences were not measurable in all parameters and activities in these studies.

Conclusions

Wearables, including at least a tri-axial accelerometer, seem promising for measuring dynamic knee laxity in the anterior-posterior and mediolateral direction. At this stage, it remains unclear if the measured outcomes completely reflect the knee instability that patients experience in daily life.

Level of Evidence

Level III.

No Difference in Bone Tunnel Enlargement and Clinical Outcome between Cortical Suspension and Hybrid Femoral Fixation in Hamstring Anterior Cruciate Ligament Reconstruction

OBJECTIVE

The best method for femoral fixation in anterior cruciate ligament reconstruction (ACLR) remains controversial. The study assesses the bone tunnel enlargement and clinical outcome in hamstring ACLR using cortical suspension or hybrid (cortical suspension and compression) femoral fixation.

METHODS

From January 2010 to December 2021, 102 patients who underwent quadruple hamstring ACLR using cortical suspension (39 patients) or hybrid (63 patients) fixation on the femoral side were retrospectively analyzed. Clinical evaluation was conducted using the international knee documentation committee score, the Lysholm score, the Tegner activity level scale, the knee injury and osteoarthritis outcome score (quality of life score), the Lachman test, and the side-to-side difference by the KT-1000 arthrometer. The complications after the surgery were also evaluated. These data were compared at baseline and last follow-up. The diameters of the femoral tunnel were calculated at three sites: the width of the entrance of the femoral tunnel, 1 cm proximal to the entrance of the femoral tunnel and the largest diameter of the femoral tunnel on magnetic resonance imaging (MRI) coronal images. Bone tunnel widening data were contrasted between MRI images conducted at least 2 years and within 2 weeks after surgery. The morphology of bone tunnel enlargement was also observed and recorded. The categorical parameters were analyzed using the χ2-test and Fisher's exact test. The continuous variables conforming to a normal distribution were analyzed using Student's t-test, and the Mann-Whitney U-test was undertaken between the two groups without normal distribution.

RESULTS

Both cortical suspension and hybrid femoral fixation in quadruple hamstring ACLR achieved significantly improved patient-reported outcome scores and knee stability compared to preoperative data. However, no significant differences were found between these two methods in clinical evaluations, postoperative complications, and patient-reported outcome scores. Although the mean diameter of the enlarged bone tunnel was lowered by an additional bioabsorbable interference screw fixation near the joint line, a statistically insignificant difference was found between the hybrid and cortical suspension fixation on the femoral side. There was no statistical difference in the distribution of enlarged bone tunnel morphology between groups.

CONCLUSIONS

No significant difference was found in the bone tunnel enlargement and clinical outcome between cortical suspension and hybrid femoral fixation in ACLR using hamstring autograft.

Lateral Extra-Articular Tenodesis with Indirect Femoral Fixation Using an Anterior Cruciate Ligament Reconstruction Suspensory Device

BACKGROUND

The lateral extra-articular tenodesis (LET) procedure associated with anterior cruciate ligament (ACL) reconstruction can be considered in selected patients to diminish the risk of persistent rotatory instability and achieve a protective effect on the graft. Several techniques have been described in the literature to treat rotatory instability. Usually, a strip of the iliotibial band (ITB) is harvested from its middle while leaving the distal insertion, then passed underneath the lateral collateral ligament and fixed on the lateral aspect of the distal femur with various fixation methods such as staples, screws, anchors or extracortical suspensory devices. Despite their effectiveness, these fixation methods may be associated with complications such as lateral pain, over-constraint and tunnel convergence.

METHODS

This study presents a detailed surgical description of a new technique to perform an LET during ACL reconstruction with any type of graft fixing the ITB strip with the sutures of the ACL femoral button, comparing its pros and cons in relation to similar techniques found in the literature.

CONCLUSIONS

This technique represents a reproducible, easy to learn and inexpensive solution to perform a lateral extra-articular tenodesis associated with an ACL reconstruction using the high-resistance sutures of the femoral button.

Functional performance tests, clinical measurements, and patient-reported outcome measures do not correlate as outcomes 1 year after anterior cruciate ligament reconstruction

PURPOSE

The results after anterior cruciate ligament reconstruction (ACLR) are evaluated by laxity measures, functional tests, and patients' perception by patient-reported outcome measures (PROMs). It is not known, if one of these evaluation instruments is representative or if outcome scores from all must be reported to obtain a full evaluation of the condition. The aim was to study the correlations between these three types of outcomes 1 year after primary ACLR.

METHOD

All adult patients (range 18-45 years) who had an ACLR between 1.1.2019 and 31.12.2021 were offered 1-year follow-up by an independent observer. Preoperative information about knee laxity and peroperative information about the condition of menisci and cartilage were registered. At 1-year follow-up clinical and instrumented knee stability and function assessed by four different hop tests were registered. Patients completed four PROMs (the Subjective International Knee Documentation Committee (IKDC) score, the Knee Numeric-Entity Evaluation Score (KNEES-ACL), the Knee injury and Osteoarthritis Outcome Score (KOOS) and the Lysholm score) and Tegner activity scale and answered anchor questions regarding satisfaction and willingness to repeat the operation.

RESULTS

A total of 190 adults attended the 1-year follow-up and 151 had all assessments. There were only a few positive and weak correlations between performance tests and PROMS and between clinical measurements and PROMS (r = 0.00-0.38), and the majority were of negligible strength. Tegner score had in general the highest correlation (low to moderate). The highest correlation was 0.53 (moderate) between the anchor question about patient satisfaction and Lysholm/IKDC scores. There was no difference in the correlations depending on meniscal condition.

CONCLUSIONS

In ACLR patients there was no clinically relevant correlation between scores obtained by PROMs, a battery of functional performance tests and instrumented laxity of the knee at 1-year follow-up. Therefore, one type of outcome cannot represent the others. This is an argument for always to include and report all three types of outcomes, and conclusions based on one type of outcome may not be sufficient.

LEVEL OF EVIDENCE

II.

[Reliability and validity of the Lever Sign Test in suspected ligament and/or meniscus injuries of the knee: a comparison between an orthopaedist and a physical therapist]

INTRODUCTION

The purpose of this study was to investigate the intertester reliability and validity of the Lever Sign Test. Intertester reliability has received little attention in previous studies. In order to make comparisons with other studies, the intertester reliability and validity of the Lachman and Anterior Drawer Tests were also calculated.

PATIENTS/MATERIAL AND METHODS

Patients between 18 and 50 years of age with suspected ligament and/or meniscus injuries were included. Exclusion criteria were suspected malignant, systemic, or central neurologic disease, acute cartilage injury, suspected fracture, or knowledge of the participant's knee findings. Testing was randomized and blinded by an experienced orthopaedic surgeon and a physical therapist. Cohen's kappa was calculated for intertester reliability. Sensitivity and specificity, positive and negative predictive value, and positive and negative likelihood ratio were calculated. MRI findings were used as the gold standard.

RESULTS

Thirty-six patients were enrolled in the study, 27 male (75%) and 9 female (25%). The prevalence of anterior cruciate ligament lesions was 44.4%. Cohen's kappa (κ) was κ=0.6 (CI 95% [0.29, 0.91]) for the Lever Sign Test, κ=0.64 (CI 95% [0.35, 0.93]) for the Lachman test, and κ=0.63 (CI 95% [0.3, 0.95]) for the Anterior Drawer Test. The sensitivity of the Lever Sign Test was 0.53 and 0.40 for the orthopaedic surgeon and physical therapist, respectively, specificity was 0.89 and 0.79, the positive predictive value was 0.80 and 0.60, the negative predictive value was 0.70 and 0.62, the positive likelihood ratio was 4.80 and 1.90, respectively, and the negative likelihood ratio was 0.76 and 0.53.

CONCLUSION

The estimated intertester reliability of the Lever Sign Test was good. The Lever Sign Test is suitable as a complement to the Lachman Test, which is considered the most valid test in the literature. The weaknesses and ambiguities of the operating mechanism of the Lever Sign Test should not be ignored and should be further explored.

Results of Anterior Cruciate Ligament Avulsion Fracture by Treatment Using Bioabsorbable Nails in Children and Adolescents

(1) Background: Anterior cruciate ligament avulsion fractures are characteristic for skeletally immature patients, and appropriate treatment is currently debated in the literature. The study aimed to evaluate the clinical and functional outcomes in patients with tibial eminence fractures treated with bioabsorbable nails in one orthopedic clinic. (2) Methods: After retrospective evaluation, we found 17 patients with tibial eminence fractures treated in orthopedic departments between January 2013 and July 2022 using bioabsorbable fixation nails. The study group comprised 12 boys and five girls aged 5 to 15.2 (average 10.1). The mean follow-up was 28 months. We diagnosed five type II fractures, ten type III fractures, and two type IV fractures according to Meyers-McKeever classification. (3) Results: We obtained a high healing rate-17 patients with the complete union on the control radiographs. We diagnosed two cases of malunion, of which one required revision surgery. Only one patient showed a slight anterior knee laxity. The treatment effect at follow-up was assessed using the Lysholm Knee Score and IKDC Score. The median Lysholm Score was 96.64 (SD 4.54), and the median IKDC Score was 84.64 (SD 3.10), which were both excellent results. (4) Conclusions: Based on our results, surgery using bioabsorbable devices for type II, III, and IV tibial eminence fractures in young individuals is an effective alternative, allowing good outcomes and restoring proper knee stability. The crucial factor for a good effect is a stable fracture fixation. Arthroscopic surgery gives good outcomes with minimal invasion. It is important not to prolong the attempts of arthroscopic reduction and to perform the open reduction to shorten the procedure's time and avoid complications.

Ensemble deep learning model for predicting anterior cruciate ligament tear from lateral knee radiograph

OBJECTIVE

To develop an ensemble deep learning model (DLM) predicting anterior cruciate ligament (ACL) tears from lateral knee radiographs and to evaluate its diagnostic performance.

MATERIALS AND METHODS

In this study, 1433 lateral knee radiographs (661 with ACL tear confirmed on MRI, 772 normal) from two medical centers were split into training (n = 1146) and test sets (n = 287). Three single DLMs respectively classifying radiographs with ACL tears, abnormal lateral femoral notches, and joint effusion were developed. An ensemble DLM predicting ACL tears was developed by combining the three DLMs via stacking method. The sensitivities, specificities, and area under the receiver operating characteristic curves (AUCs) of the DLMs and three radiologists were compared using McNemar test and Delong test. Subgroup analysis was performed to identify the radiologic features associated with the sensitivity.

RESULTS

The sensitivity, specificity, and AUC of the ensemble DLM were 86.8% (95% confidence interval [CI], 79.9-92.0%), 89.4% (95% CI, 83.4-93.8%), and 0.927 (95% CI, 0.891-0.954), achieving diagnostic performance comparable with that of a musculoskeletal radiologist (P = 0.193, McNemar test; P = 0.131, Delong test). The AUC of the ensemble DLM was significantly higher than those of non-musculoskeletal radiologists (P = 0.043, P < 0.001). The sensitivity of the DLM was higher than that of the radiologists in the absence of an abnormal lateral femoral notch or joint effusion.

CONCLUSION

The diagnostic performance of the ensemble DLM in predicting lateral knee radiographs with ACL tears was comparable to that of a musculoskeletal radiologist.

PCL insufficient patients with increased translational and rotational passive knee joint laxity have no increased range of anterior-posterior and rotational tibiofemoral motion during level walking

Passive translational tibiofemoral laxity has been extensively examined in posterior cruciate ligament (PCL) insufficient patients and belongs to the standard clinical assessment. However, objective measurements of passive rotational knee laxity, as well as range of tibiofemoral motion during active movements, are both not well understood. None of these are currently quantified in clinical evaluations of patients with PCL insufficiency. The objective of this study was to quantify passive translational and rotational knee laxity as well as range of anterior–posterior and rotational tibiofemoral motion during level walking in a PCL insufficient patient cohort as a basis for any later clinical evaluation and therapy. The laxity of 9 patient knees with isolated PCL insufficiency or additionally posterolateral corner (PLC) insufficiency (8 males, 1 female, age 36.78 ± 7.46 years) were analysed and compared to the contralateral (CL) knees. A rotometer device with a C-arm fluoroscope was used to assess the passive tibiofemoral rotational laxity while stress radiography was used to evaluate passive translational tibiofemoral laxity. Functional gait analysis was used to examine the range of anterior–posterior and rotational tibiofemoral motion during level walking. Passive translational laxity was significantly increased in PCL insufficient knees in comparison to the CL sides (15.5 ± 5.9 mm vs. 3.7 ± 1.9 mm, p < 0.01). Also, passive rotational laxity was significantly higher compared to the CL knees (26.1 ± 8.2° vs. 20.6 ± 5.6° at 90° knee flexion, p < 0.01; 19.0 ± 6.9° vs. 15.5 ± 5.9° at 60° knee flexion, p = 0.04). No significant differences were observed for the rotational (16.3 ± 3.7° vs. 15.2 ± 3.6°, p = 0.43) and translational (17.0 ± 5.4 mm vs. 16.1 ± 2.8 mm, p = 0.55) range of anterior–posterior and rotational tibiofemoral motion during level walking conditions for PCL insufficient knees compared to CL knees respectively. The present study illustrates that patients with PCL insufficiency show a substantial increased passive tibiofemoral laxity, not only in tibiofemoral translation but also in tibiofemoral rotation. Our data indicate that this increased passive multiplanar knee joint laxity can be widely compensated during level walking. Further studies should investigate progressive changes in knee joint laxity and kinematics post PCL injury and reconstruction to judge the individual need for therapy and effects of physiotherapy such as quadriceps force training on gait patterns in PCL insufficient patients.

Utility of Diagnostic Ultrasound in the Assessment of Patellar Instability

Background

The use of imaging to diagnose patellofemoral instability is often limited by the inability to dynamically load the joint during assessment. Therefore, the diagnosis is typically based on physical examination using the glide test to assess and quantify lateral patellar translation. However, precise quantification with this technique remains difficult.

Purpose

To quantify patellar position using ultrasound imaging under dynamic loading conditions to distinguish between knees with and without medial patellofemoral complex (MPFC) injury.

Study Design

Controlled laboratory study.

Methods

In 10 cadaveric knees, the medial patellofemoral distance was measured to quantify patellar position from 0° to 40° of knee flexion at 10° increments. Knees were evaluated at each flexion angle under unloaded conditions and with 20 N of laterally directed force on the patella to mimic the glide test. Patellar position measurements were made on ultrasound images obtained before and after MPFC transection and compared for significant differences. To determine the ability of medial patellofemoral measurements to differentiate between MPFC-intact and MPFC-deficient states, area under the receiver operating characteristic (ROC) curve analysis and the Delong test were used. The optimal cutoff value to distinguish between the deficient and intact states was determined using the Youden J statistic.

Results

A significant increase in medial patellofemoral distance was observed in the MPFC-deficient state as compared with the intact state at all flexion angles (P = .005 to P < .001). When compared with the intact state, MPFC deficiency increased medial patellofemoral distance by 32.8% (6 mm) at 20° of knee flexion under 20-N load. Based on ROC analysis and the J statistic, the optimal threshold for identifying MPFC injury was 19.2 mm of medial patellofemoral distance at 20° of flexion under dynamic loading conditions (area under the ROC curve = 0.93, sensitivity = 77.8%, specificity = 100%, accuracy = 88.9%).

Conclusion

Using dynamic ultrasound assessment, we found that medial patellofemoral distance significantly increases with disruption of the MPFC.

Clinical Relevance

Dynamic ultrasound measurements can be used to accurately detect the presence of complete MPFC injury.

Reliability of a Novel Automatic Knee Arthrometer for Measuring Knee Laxity After Anterior Cruciate Ligament Ruptures

Background:

The accuracy of existing devices for measuring knee laxity is adversely affected by examiner reliability.

Purpose:

To compare the accuracy of a novel automatic knee arthrometer (AKA) to that of the KT-2000 arthrometer for measuring knee laxity after anterior cruciate ligament (ACL) ruptures.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

We measured anterior displacement and the anterior displacement difference (ADD) at 134 N of anterior force in 221 healthy volunteers and 200 patients with ACL ruptures. All trials were performed by the same 2 examiners. We first analyzed the effects of examiner, side assessed, and device type using the intraclass correlation coefficient (ICC), t test, and F test. We then used the receiver operating characteristic curve to compare the diagnostic value of the measurements between devices.

Results:

In repeated measurements for a single healthy volunteer, there were no differences in the variance of the measurements between sides according to the AKA (standard deviation of right vs left knee for examiner A: 0.43 vs 0.58 mm, respectively [P = .39]; for examiner B: 0.49 vs 0.77 mm, respectively [P = .81]), while the KT-2000 measurements showed differences (standard deviation of right vs left knee for examiner A: 1.47 vs 0.80 mm, respectively [P = .02]; for examiner B: 1.78 vs 0.91 mm, respectively [P = .01]). The ADD assessed by the AKA was not significantly different between examiners A and B (0.50 vs 0.75 mm, respectively; P = .27; ICC = 0.83), but the KT-2000 showed a difference (1.07 vs 2.01 mm, respectively; P = .01; ICC = 0.55). The ADD of 20 healthy volunteers assessed by the AKA was less than that by the KT-2000 (0.98 vs 1.41 mm, respectively; P = .04). When comparing the diagnostic value of the 2 devices in the sample of 200 patients with ACL ruptures and 200 healthy controls, the area under the receiver operating characteristic curve for the AKA was larger than that for the KT-2000 (0.93 vs 0.87, respectively; P ≤ .01), and the threshold values were 1.75 and 2.73 mm, respectively.

Conclusion:

The AKA can be used to determine the degree of knee laxity in ACL injuries and to provide indications for treatment.

Single-joint Hybrid Assistive Limb in Knee Rehabilitation after ACL Reconstruction: An Open-label Feasibility and Safety Trial

Objectives:

Methods:

Results:

Conclusions:

Common Physical Examination Tests for Patellofemoral Instability Demonstrate Weak Inter-Rater Reliability

Purpose

The purpose of this study was to assess the inter-rater reliability of 3 common physical examination assessments, the Q-angle, J-sign, and apprehension test, used to evaluate patients presenting with recurrent lateral patellofemoral instability.

Methods

A consecutive sample of 38 subjects with recurrent lateral patellofemoral instability in 2013 were included in this reliability study. Two orthopaedic surgeons performed the physical examination maneuvers blinded to each other. The physical examination tests were performed bilaterally and included the Q angle, the J-sign, and the apprehension test. To measure the inter-rater reliability, an intraclass correlation coefficient (ICC 2,κ) was used for both legs independently for Q-angle measurements. A Cohen’s kappa was used to measure the inter-rater reliability for the J-sign and the apprehension test.

Results

The measurement of the Q-angle demonstrated poor reliability (ICC 2,κ 0.18-0.44). The assessment of the J-sign demonstrated fair to moderate reliability (κ = 0.31 – 0.41), and the evaluation of apprehension demonstrated fair to substantial reliability (κ = 0.30 – 0.65). All 3 clinical tests demonstrated substantial variability comparing the reliability on the right and left limbs. Assessment of the quality of apprehension demonstrated good agreement between the examiners.

Conclusions

In this study of patients with recurrent lateral patellofemoral instability the common physical examination tests, Q-angle, J-sign, and apprehension demonstrated weak inter-rater reliability. These results indicate that these tests are not reliable for communication between health care practitioners or as evaluations for clinical research.

Level of Evidence

Level IV, therapeutic case series.

Is it worth to perform initial non-operative treatment for patients with acute ACL injury?: a prospective cohort prognostic study

Purpose

To evaluate the result of implementing an initial non-operative treatment program for an acute ACL injury and to find if the timing of initiating the non-operative treatment is significant.

Methods

This study included a prospective cohort of 85 consecutive patients with acute ACL injury who were treated according to the above strategy for the initial 3 months with 1-year follow-up. Clinical evaluations were made by Lysholm score, Tegner activity score, Lachman test (LT), pivot-shit test (PST), and the side to side difference (SSD) by KT-2000 arthrometer. The results were analyzed according to the timing of initiating the non-operative treatment.

Results

Initially, 84% of the patients showed LT and PST ≤ grade 1, and 16% with ≥grade 2. At 1-year follow-up, 77 patients (91%) with LT and PST ≤ grade 1 did not receive reconstruction as copers and 8 patients with LT or PST ≥ grade 2 required reconstruction (six patients received the operation and two refused). The patients with LT and PST ≤ grade 1 showed average Lysholm score 91.2, average SSD 2.5 mm, and mean Tegner score decreased from 6.9 (pre-injury) to 6.2. Patients who started the non-operative treatment within 2 weeks after injury revealed superior rates of grade 0 or 1 instability than those who commenced the treatment later than 2 weeks after injury (P = 0.043).

Conclusions

Implementing a non-operative treatment with brace in acute phase of ACL injury appears to be an effective and viable option to achieve a reasonable clinical outcome. We recommend earlier initiation of the non-operative treatment to obtain a better result in patients with acute ACL injury.

Supplementary Information

The online version contains supplementary material available at 10.1186/s43019-021-00094-3.

Patellar Apprehension Is Reduced in Most but Not All Patients After Successful Patellar Stabilization

BACKGROUND

The clinical sign of patellar laxity and the associated symptom of apprehension are mainstays of the physical examination of patellofemoral instability. The apprehension test is widely used as a diagnostic tool and also as an outcome following patellofemoral stabilization surgery. Despite widespread use, the validity, reliability, and responsiveness of the apprehension test have not been established.

PURPOSE

The primary purpose was to evaluate patellar apprehension in patients with recurrent patellofemoral instability to determine if the apprehension test is valid, reliable, and responsive to change after medial patellofemoral ligament (MPFL) reconstruction. The secondary purposes were to concurrently validate patient-rated to surgeon-rated apprehension and to correlate patient-rated apprehension with pathoanatomic characteristics and quality-of-life scores.

STUDY DESIGN

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

METHODS

A total of 89 patients underwent an MPFL reconstruction and were assessed preoperatively and at 6, 12, and 24 months postoperatively. The patellar apprehension test was performed in neutral extension and 30° of knee flexion. Patient- and surgeon-rated apprehension were graded on a 10-cm visual analog scale (VAS), and the quality of the apprehension symptoms were recorded. Risk factors for patellofemoral instability were documented, and the Banff Patellofemoral Instability Score 2.0 (BPII 2.0) was used to measure disease-specific quality of life.

RESULTS

The patient-rated and surgeon-rated apprehension VAS scores were statistically significantly reduced from pre- to postoperatively (P < .001, large effect size) for the neutral extension and 30° of flexion apprehension tests. Postoperatively, over 56% of patients reported a negative apprehension test. Up to 15.7% of patients with positive preoperative apprehension did not demonstrate a reduction postoperatively. Patients consistently graded their apprehension symptoms higher in both quantity and quality than the surgeon. The intraclass correlation coefficient (ICC [2, k]) assessing the preoperative patient and surgeon VAS scores revealed moderate interrater reliability in neutral extension (r = 0.60) and weak interrater reliability in 30° of flexion (r = 0.42). The postoperative ICC (2, k) demonstrated strong interrater reliability for both neutral extension (r = 0.74) and 30° of flexion (r = 0.73). The symptoms of apprehension (physical, emotional, and/or physiological) decreased substantially after surgery. The correlation of postoperative patient-rated apprehension VAS and BPII 2.0 scores demonstrated that less residual patellar apprehension was associated with higher BPII scores in neutral extension (r = -0.35, P = .001). There were no statistically significant correlations revealed between the patient-rated postoperative apprehension VAS and pathoanatomic risk factors. BPII 2.0 scores improved pre- to postoperatively from a mean of 27.6 (SD, 15.7) to 74.3 (SD, 18.3). Three patients (3.4%) sustained a patellar dislocation postoperatively.

CONCLUSION

The patellar apprehension test demonstrated strong validity and responsiveness to change. Interrater reliability ranged from weak to strong. There was a statistically significant reduction in apprehension after patellofemoral stabilization in the majority of patients. Patients graded their apprehension symptoms significantly higher in both quantity and quality than the surgeon. Persistent patellar apprehension after stabilization was correlated with lower quality-of-life scores. No relationship could be found between persistent apprehension and patellofemoral risk factors. These results suggest that use of the apprehension tests as an outcome is inappropriate until further validation is performed.

Similar functional outcomes of arthroscopic reconstruction in patients with isolated Posterior Cruciate Ligament (PCL) and combined Anterior Cruciate Ligament (ACL) and PCL tears

BACKGROUND

Posterior Cruciate Ligament (PCL) injuries seldom occur in isolation and majority occurs in conjugation with other ligament injuries. Posterior Cruciate Ligament (PCL) reconstruction continues to be taken into consideration as a complicated surgical procedure, with heterogeneity in literature regarding clinical and functional outcomes in isolated PCL and combined ACL and PCL injuries.

METHODS

The retrospective evaluation of patients with isolated PCL reconstruction (group 1) and combined Anterior Cruciate Ligament (ACL) and PCL reconstruction (group 2) was performed. A total of 66 patients with either isolated PCL or combined ACL and PCL reconstruction surgeries that met the inclusion criteria, were included in the study. These patients were assessed for functional outcome scores including Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, Lysholm score, International Knee Documentation Committee (IKDC) and Tegner activity score at a minimum follow-up of 5 years.

RESULTS

The mean follow-up of patients was 82.09 ± 12.43 months in group 1 and 79.36 ± 11.24 months in group 2, with a total of 29 patients in group 1 and 21 patients in group 2. Both the groups were found to be comparable in terms of age, gender, duration of injury and pre-injury Tegner activity level. Post-surgical functional outcome scores (WOMAC score, Lysholm score and Tegner score) were found to be comparable between 2 groups at a mean follow-up of 5 years. Further, 22 patients in group 1 and 16 patients in group 2 had normal or near normal objective IKDC outcome scores at a mean follow-up of 5 years.

CONCLUSIONS

No differences were observed in functional outcome scores (WOMAC score, Lysholm score, Tegner score and IKDC score) between isolated reconstructed PCL and combined ACL and PCL reconstructed patients.

Clinical and Radiographic Outcomes of Anterior Cruciate Ligament Reconstruction With Hamstring Tendon Graft and Femoral Cortical Button Fixation at Minimum 20-Year Follow-up

BACKGROUND

The short-term outcomes of anterior cruciate ligament (ACL) reconstruction with bone-patellar tendon-bone or hamstring tendon (HT) graft are excellent with good clinical stability and patient-reported outcomes. Although some studies have reported the long-term outcomes of bone-patellar tendon-bone graft ACL reconstruction, few have reported the outcomes of HT graft ACL reconstruction.

PURPOSE

To assess clinical and radiographic outcomes of HT graft ACL reconstruction with femoral cortical button fixation at a minimum 20-year follow-up.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A prospective study was performed in which all patients undergoing isolated transtibial primary ACL reconstruction between 1994 and 1996 with HT graft and femoral cortical button fixation were assessed clinically and radiographically. Follow-up was obtained in 48 of 94 patients (51%). Median (interquartile range) age at operation was 31 years (26-39 years); median follow-up was 21 years (20-22 years); 65% were male; and 48% had meniscal injury at surgery and underwent partial meniscectomy. Graft rupture, reoperation, and contralateral injury rates were assessed; clinical stability was measured using the KT-1000 arthrometer; patient-reported outcomes were assessed (International Knee Documentation Committee [IKDC], Lysholm, Forgotten Joint Score, Tegner activity, Knee injury and Osteoarthritis Outcome Score [KOOS], Anterior Cruciate Ligament Quality of Life [ACL-QOL], EuroQol 5-Dimension 5-Level [EQ-5D-5L]); and radiographic osteoarthritis (defined as Kellgren-Lawrence grade ≥2) was assessed for the ipsilateral and the contralateral knee.

RESULTS

Graft rupture occurred in 4 patients (8%), contralateral injury in 4 patients (8%), and reoperation in 15 patients (31%), which consisted mainly of meniscal tears or hardware removal. In patients with an intact graft, excellent patient-reported outcome measures (PROMs) were noted, with a median Lysholm of 90 (78-100), subjective IKDC of 86 (72-95), and KOOS-Sports of 86 (58-100). There was low awareness of the operated knee (Forgotten Joint Score, 81 [60-96]) and good quality of life (ACL-QOL, 85 [75-94]; EQ-5D-5L, 0.87 [0.83-1.00]). Median side-to-side difference, as measured with the KT-1000 arthrometer, was 1 mm (-1 to 3 mm). Radiographic osteoarthritis was evident in 49% of ipsilateral and 10% of contralateral knees and was associated with meniscectomy at index surgery and decreased PROMs at follow-up.

CONCLUSION

Long-term outcomes of transtibial HT graft ACL reconstruction with femoral cortical button fixation are generally good with a low failure rate, low awareness of the operated knee, and good clinical stability. Radiographic osteoarthritis was evident in approximately half of the patients at 20-year follow-up and was associated with meniscectomy at index surgery and decreased PROMs at follow-up.

Dynamic Evaluation of Patellofemoral Instability: A Clinical Reality or Just a Research Field? A Literature review

Patellofemoral instability (PFI) is one of the most disabling conditions in the knee, often affecting young individuals. Despite its not uncommon presentation, the underlying biomechanical features leading to this entity are not entirely understood. The suitability of classic physical examination manoeuvres and imaging tests is a matter of discussion among treating surgeons, and so are the findings provided by these means. A potential cause for this lack of consensus is the fact that, classically, the diagnostic approach for PFI has relied on statically obtained data. Many authors advocate for the study of this entity in a dynamic scenario, closer to the actual situation in which the instability episodes occur. In this literature review, we have compiled the available data from the last decades regarding dynamic evaluation methods for PFI and related conditions. Several categories are presented, grouping the related techniques and devices: physical examination, imaging modalities (ultrasound (US), magnetic resonance imaging (MRI), computed tomography (CT) and combined methods), arthroscopic evaluation, and others. In conclusion, although a vast number of quality studies are presented, in which comprehensive data about the biomechanics of the patellofemoral joint (PFJ) are described, this evidence has not yet reached clinical practice universally. Most of the data still stays in the research field and is seldom employed to assist a better understanding of the PFI cases and their ideal treatment targets.

In vivo gait kinematics of the knee after anatomical and non-anatomical single-bundle anterior cruciate ligament reconstruction-a prospective study

Background

The factors that influence functions of knees after anterior cruciate ligament reconstruction (ACLR) still remains uncertain. The functional restoration of knees after ACLR can be reflected on gait kinematics restoration. The purpose of this study was to evaluate the gait kinematics and clinical outcomes of knees after anatomical and non-anatomical single-bundle ACLR during level walking.

Methods

Thirty-four patients with unilateral primary single-bundle ACLR and 18 healthy people were recruited. Patients were divided into anatomical reconstruction group (AR group; n=13) and non-anatomical reconstruction group (Non-AR group; n=21) according to Bernard Quadrant method. The ACL graft orientations on coronal and sagittal planes were measured on 3D models from medical images. The 6 degrees of freedom (DOF) kinematics of knees and range of motion (ROM) of 6 DOF kinematics were measured with a portable optical tracking system. The comparison of 6 DOF kinematics and ROM of 6 DOF kinematics were performed between the ACLR knees and contralateral knees. The following assessments were also performed including clinical examination, KT-2000 arthrometer measurement, International Knee Documentation Committee (IKDC) and Lysholm scores.

Results

All patients reached a minimum follow-up of 6 months (10±4 months). For AR group and Non-AR group, no statistically significant differences were observed in gait kinematics between the ACLR knees and contralateral knees. No statistically significant differences between the ACLR knees and contralateral knees were observed in terms of ROM of 6 DOF kinematics in AR group. However, in Non-AR group, the ACLR knees exhibited significant ROM of anterior-posterior translation by approximately 0.5 cm than contralateral knees (P=0.0080). No statistically significant differences between the two groups were observed regarding IKDC subjective score, Lysholm score and KT-2000 arthrometer test.

Conclusions

The anatomical ACLR can restore close to normal gait kinematics and ROM of 6 DOF kinematics compared with non-anatomical ACLR. The ACL graft after anatomical ACLR simulated native ACL fibers to function in terms of graft orientation.

Supine lateral radiographs at 90° of knee flexion have a similar diagnostic accuracy for chronic posterior cruciate ligament injuries as stress radiographs

PURPOSE

This study aimed to evaluate whether supine lateral radiographs (SLRs) could replace stress radiographs for diagnosing chronic posterior cruciate ligament (PCL) injuries and identifying combined PCL injuries (defined as PCL injury with medial collateral ligament or posterolateral ligament complex injury).

METHODS

In this retrospective study, both SLRs at 30° and 90° of knee flexion (30/90 SLRs) and Telos stress radiographs of patients with chronic PCL injuries (n = 38) and only 30/90 SLRs of healthy controls (n = 84) were taken. Injured-to-normal differences on 30/90 SLRs and stress radiographs were assessed. Correlation analysis was performed to evaluate injured-to-normal differences on 30/90 SLRs and stress radiographs in patients with chronic PCL injury. Subgroup analysis was performed to compare injured-to-normal differences on 30/90 SLRs and stress radiographs between the isolated and combined PCL injury groups. Receiver operating characteristic curves based on 30/90 SLRs were calculated to determine the cut-off value for diagnosing chronic PCL injury and identifying combined PCL injury.

RESULTS

Injured-to-normal differences on both 30 SLRs (3.1 ± 3.6 vs 1.6 ± 1.2, P = 0.019) and 90 SLRs (7.5 ± 3.5 vs 1.2 ± 1.0, P < 0.001) were significantly greater in patients with chronic PCL injuries than in healthy controls. Further, 90 SLRs had a highly accurate diagnostic value for chronic PCL injuries (area under the curve 0.958). The cut-off value for diagnosing chronic PCL injuries based on 90 SLRs was 3.0 mm (sensitivity, 94.7%; specificity, 92.9%). Injured-to-normal differences on 30/90 SLRs were significantly correlated with those on stress radiographs. The correlation coefficients were 0.397 (P = 0.014) for 30 SLRs and 0.605 (P < 0.001) for 90 SLRs. The cut-off value for diagnosing combined PCL injuries based on 90 SLRs was 9.6 mm (area under the curve 0.72).

CONCLUSIONS

The diagnostic accuracy of 90 SLRs for chronic PCL injuries was similar to that of stress radiographs. Therefore, the 90 SLRs are reliable alternative method to assess the posterior knee laxity when the stress radiographs are not available.

LEVEL OF EVIDENCE

Level IV, case series.

Knee-related quality of life, functional results and osteoarthritis at a minimum of 20 years' follow-up after anterior cruciate ligament reconstruction

BACKGROUND

Few studies in the literature show results with more than 20 years of follow-up after anterior cruciate ligament reconstruction (ACLR). The main purpose of this retrospective study was to describe knee-specific quality of life, functional results and prevalence of osteoarthritis (OA) of the knee in patients with ACLR using bone-patellar tendon-bone (BPTB) autograft with ultra-long-term follow-up.

METHODS

Prospective analyzed data included demographics, meniscus status, radiographic OA, KT-1000 arthrometer measurements and physical examinations. KOOS, Lysholm and IKDC subjective surveys were conducted. Multivariate and univariate logistic models were used to determine the effect of potential predictors of OA and symptomatic knees.

RESULTS

Seventy-two knees were included at a median follow-up of 22 (IQR 21-25) years postoperatively. Radiographic scores were normal in 15%, nearly normal in 57%, abnormal in 18% and severely abnormal in 10%. Multivariate analysis showed that the predictive factor for the presence of OA in the long-term was an associated meniscal lesion; patients with meniscal lesions were 3.9 times as likely to develop OA in comparison with those without meniscal injury. The subjective scores were progressively and significantly lower as the level of OA was greater.

CONCLUSION

At a median of 22 years of follow-up, this study shows that patellar tendon autograft ACL reconstruction provides good clinical outcomes, with clinically objective knee stability and a 28% prevalence of OA. Additionally, we identified that meniscal injury at time of surgery was an independent predictor of OA.

LEVEL OF EVIDENCE

Level IV; case series.

A non-invasive biomechanical device to quantify knee rotational laxity: Verification of the device in human cadaveric specimens

BACKGROUND

Biomechanical measurement tools have been developed and widely used to precisely quantify knee anterior-posterior laxity after anterior cruciate ligament (ACL) injury. However, validated objective device to document knee rotational laxity, though being developed by different researchers, are not yet widely used in the daily clinical practice. A new biomechanical device was developed to quantify knee internal and external rotations.

METHODS

The reliability of the new biomechanical device which measures knee rotations were tested. Different torques (1-10Nm) were applied by the device to internally and externally rotate human cadaveric knees, which were held in a flexion angle of 30°. The rotations were measured by the device in degrees. There were two independent testers, and each tester carried out three trials. Intra-rater and inter-rater reliability were quantified in terms of intraclass correlation (ICC) coefficient among trials and between testers. The device was verified by the comparison with a computer assisted navigation system. ICC was measured. Mean, standard deviation and 95% confident interval of the difference as well as the root mean square difference were calculated. The correlations were deemed to be reliable if the ICC was above 0.75.

RESULTS

The intra-rater and inter-rater reliability achieved high correlation for both internal and external rotation, ranged from 0.959 to 0.992. ICC between the proposed meter and the navigation system for both internal and external rotation was 0.78. The mean differences were 2.3° and 2.5° for internal and external rotation respectively.

CONCLUSIONS

A new knee rotational laxity meter was proposed in this study. Its reliability was verified by showing high correlation among trials. It also showed good correlation to a gold standard of measurement. It might be used to document knee rotational laxity for various purposes, especially after ACL injury, after further validation of the device in human subjects.

Knee Ligament Instability Patterns: What Is Clinically Important

The knee dislocation is a severe, complex injury that can be difficult to treat and is fraught with complications. The first step in a successful reconstruction of a multiple ligamentous knee injury is gaining an accurate and thorough understanding of the pattern of instability imparted by the injury. Evaluation begins with a detailed review of radiographic and advanced imaging studies followed by a thorough physical examination, often done under anesthesia, in conjunction with dynamic fluoroscopy. Failure to identify and reconstruct a damaged ligament may place undue stress on adjacent structures, resulting in complications and potential failure of the surgical procedure.

The Role of Osteotomy for the Treatment of PCL Injuries

PURPOSE OF REVIEW

The purposes of this review are to (1) describe the anatomic and biomechanical rationale for high tibial osteotomy (HTO) in the setting of posterior cruciate ligament (PCL) deficiency, (2) review the indications for concomitant HTO and PCL reconstruction, (3) provide guidance for the clinical assessment of the patient with suspected PCL deficiency, and (4) summarize the key surgical steps necessary to attain the appropriate sagittal and coronal plane corrections.

RECENT FINDINGS

The preponderance of available biomechanical data pertaining to the PCL-deficient knee suggests that an increased proximal tibial slope limits posterior tibial translation under axial compressive loads. Moreover, recent clinical data has demonstrated that decreased proximal tibial slope may exacerbate residual anterior-posterior laxity and jeopardize the durability of PCL reconstruction. Thus, in the setting of PCL deficiency, an HTO that increases the posterior tibial slope may be advisable. HTO may be an important treatment adjunct in the surgical management of PCL deficiency. In the setting of chronic injuries and varus malalignment, HTO should be considered in order to ensure a durable ligamentous reconstruction and forestall the progression of secondary osteoarthritis.

Evaluation of reproducibility of robotic knee testing device (GNRB) on 60 healthy knees

Introduction

There is a main concern about the usefulness and the accuracy of the different laximeters. The GnrB device is becoming more popular, but according to the literature it's not clear whether it is fully reliable.

Objective

GNRB laxity measurements are not reproducible for measurement of anterior translation of the tibia.

Material and methods

We analyzed the reproducibility of GNRB measurements in healthy subjects by the Test-Retest method in 2 sessions.

Results

30 pairs of healthy knees were assessed. Test-Retest agreement was poor for both absolute values and for differentials at 134 and 200 N with an intra-class correlation ranging from 0.210 to 0.486. There was a significant differance in anterior tibial translation, in side-to-side difference, according to the patellar pressure.

Conclusion

The reproducibility is found to be poor under optimum conditions of comparability. The patellar pressure influences strongly thelaxity value.

Outcomes after arthroscopic fixation of tibial eminence fractures with bioabsorbable nails in skeletally immature patients

The aim of this paper is to report the outcomes and any complications with arthroscopic bioabsorbable nail fixation of tibial eminence fractures in skeletally immature patients. We retrospectively reviewed all surgically treated tibial eminence fractures treated by a single surgeon and seven patients were identified with a minimum 2-year follow-up. Mean deficits of flexion and extension were minimal. Satisfactory Tegner levels, Lysholm knee scores, and International Knee Documentation Committee subjective scores were reported. Arthroscopic fixation of tibial eminence fractures with bioabsorbable nails yields satisfactory outcomes for this uncommon injury and obviates the need for future hardware removal.

Anterior tibial laxity using the GNRB® device in healthy knees

BACKGROUND

GRNB® is a non-radiating power tool that allows the evaluation of the anterior tibial translation.

HYPOTHESIS

The pressure exerted by the system against the patella and the body mass index (BMI) could affect the anterior tibial translation when we repeat the measurements in healthy knees.

MATERIALS AND METHODS

We retrospectively evaluated the measurements of anterior knee laxity in healthy knees carried out by the GNRB® in 69 consecutive patients who underwent anterior cruciate ligament (ACL) repair in the contralateral knee. Two measurements were carried out, the initial measurements (M1), and then repeated at a mean of seven months (M2) (4.9 to 13months).

RESULTS

There were 38 women and 31 men with an average age of 31years. In healthy knees, the Mean average anterior translation was 5.4±4mm with an average patellar force of 35.8 at time M1. The average anterior translation was 4.9±4mm with an average patellar force of 47 at time M2. There was a significant difference between the measurements M1 and M2 (P<0.03). The tightening force was significantly different between the two sets of measurements (P<10-7). There was a negative correlation between the pressure applied on the patella and anterior knee laxity (P<0.01).

CONCLUSION

The pressure force exerted on the patella during GNRB® affects the measurement of anterior laxity in healthy knees. This raises the problem of the reproducibility of the measurements during repeated examinations at different times.

THE DIAGNOSTIC ACCURACY OF THE LEVER SIGN FOR DETECTING ANTERIOR CRUCIATE LIGAMENT INJURY

Background

An alternative physical examination procedure for evaluating the integrity of the anterior cruciate ligament (ACL) has been proposed in the literature but has not been validated in a broad population of patients with a symptomatic complaint of knee pain for its diagnostic value.

Purpose

To investigate the diagnostic accuracy of the Lever Sign to detect ACL tears and compare the results to Lachman testing in both supine and prone positions.

Study design

Prospective, blinded, diagnostic accuracy study.

Methods

Sixty-two consecutive patients with a complaint of knee pain were independently evaluated for the status of the ACL's integrity with the Lever Sign and the Lachman test in a prone and supine by a blinded examiner before any other diagnostic assessments were completed.

Results

Twenty-four of the 60 patients included in the analysis had a torn ACL resulting in a prevalence of 40%. The sensitivity of the Lever Sign, prone, and supine Lachman tests were 38, 83, and 67 % respectively and the specificity was 72, 89, and 97% resulting in positive likelihood ratios of 1.4, 7.5, and 24 and negative likelihood ratios of 0.86, 0.19, and 0.34 respectively. The positive predictive values were 47, 83, and 94% and the negative predictive values were 63, 89, and 81% respectively. The diagnostic odds ratios were 1.6, 40, and 70 with a number needed to diagnose of 10.3, 1.4, and 1.6 respectively.

Conclusions

The results of this study suggest that Lever Sign, in isolation, does not accurately detect the status of the ACL. During the clinical examination, the Lever Sign should be used as an adjunct to the gold standard assessment technique of anterior tibial translation assessment as employed in the Lachman tests in either prone or supine position.

Level of Evidence

2.

Critical Analysis of the Lever Test for Diagnosis of Anterior Cruciate Ligament Insufficiency

PURPOSE

To critically analyze the "lever test" in detecting anterior cruciate ligament (ACL) tears and to compare its accuracy with the Lachman, anterior drawer (AD), and pivot shift tests.

METHODS

From June 2014 to June 2015, 91 subjects were analyzed. Inclusion criteria were subjects aged 16 to 60 years, presenting after a knee injury with subjective swelling, or an objective effusion and an uninjured normal contralateral knee for comparison. Exclusion criteria included previous knee ligamentous reconstruction, fracture of the distal femur or proximal tibia, bilateral knee injuries, or known cruciate ligament tear. The Lachman, AD, pivot shift, and lever tests were performed in the office by 2 board-certified orthopaedic surgeons with patient awake. Examiners were blinded to the presence or absence of ACL injury. Magnetic resonance imaging was used to determine injury. Sensitivity, specificity, and accuracy were evaluated for all 4 tests. Accuracy was compared using χ-square and receiver operator curves.

RESULTS

Average subject age was 28 ± 11 years (61 males, 30 females). Seventy-one (79%) had ACL tears diagnosed by magnetic resonance imaging. The sensitivity, specificity, and accuracy of the lever test were 83%, 80%, and 82%, respectively. Accuracy was not statistically different from the Lachman, AD, and pivot shift tests (P = .78, .99, .07, respectively). Subanalyses were performed based on the presence of another ligament tear, timing of injury, and the presence of a meniscus tear. Although the groups were smaller and thus underpowered, the results were reported. Neither the presence of another ligament tear nor the timing of the injury affected accuracy (P = .62 and P = .47); however, the presence of a meniscus tear decreased its accuracy (P = .003).

CONCLUSIONS

The lever test showed high sensitivity, specificity, and overall accuracy in the detection of ACL tears. The accuracy of the lever test was not significantly different from the Lachman, AD, or pivot shift tests.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Demographics and Injuries Associated With Knee Dislocation: A Prospective Review of 303 Patients

Background:

Information on the incidence, injury mechanisms, ligament injury patterns, and associated injuries of knee dislocations is lacking in the literature. There is a need to characterize ligament injury patterns and associated injuries in knee dislocations to avoid missing common associated diagnoses and to plan surgical treatment.

Purpose:

To evaluate patient demographics, ligament injury patterns and associated injury patterns, and associated injuries in patients with knee dislocation.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

A total of 303 patients with knee dislocations treated at a single level 1 trauma center were followed prospectively. Injury mechanism; ligament injury patterns; associated neurovascular, meniscal, and cartilage injuries; and surgical complications were recorded. The Schenck knee dislocation classification was used to classify the ligament injury patterns.

Results:

The mean age at injury was 37.8 ± 15.3 years. Of the 303 patients included, 65% were male and 35% were female. There was an equal distribution of high-energy and low-energy injuries. Injury to 3 major ligaments was the most common, with Schenck classification type KD III-M constituting 52.4% of the injuries and KD III-L comprising 28.1%. Meniscal injuries and cartilage injuries occurred in 37.3% and 28.3% of patients, respectively. Patients with acute injuries had significantly lower odds of a cartilage injury than those with chronic injuries (odds ratio [OR], 0.28; 95% CI, 0.15-0.50; P < .001). Peroneal nerve injuries were recorded in 19.2% of patients (10.9% partial and 8.3% complete deficit), while vascular injuries were recorded in 5%. The odds of having a common peroneal nerve injury were 42 times greater (P < .001) among those with posterolateral corner injury (KD III-L) than those without. The odds for popliteal artery injury were 9 times greater (P = .001) among those with KD III-L injuries than other ligament injury types.

Conclusion:

Medial-sided bicruciate injuries were the most common injury pattern in knee dislocations. Cartilage injuries were common in chronically treated patients. There was a significant risk of peroneal nerve injury with lateral-sided injuries.

Outcomes After Posterior Cruciate Ligament (PCL) Reconstruction in Patients With Isolated and Combined PCL Tears

Background:

Posterior cruciate ligament (PCL) reconstructions are rarely performed compared with that for the anterior cruciate ligament (ACL).

Purpose:

To evaluate the clinical and functional outcome after isolated or multiligament PCL reconstruction.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Patients who underwent PCL reconstruction between 2002 and 2010 were included. Standardized follow-up was performed between 2012 and 2013 and consisted of subjective scores (Tegner activity score, Knee injury and Osteoarthritis Outcome Score [KOOS], and subjective International Knee Documentation Committee [IKDC] score) and objective measures, including knee laxity (KT-1000), extension strength, and overall IKDC score.

Results:

One hundred ninety-six patients were identified, of which 172 were available for postoperative follow-up: 39.3% with isolated PCL and 60.7% with multiligament injury. One hundred ten patients were available to complete both clinical follow-up and subjective questionnaires; 62 patients returned the subjective questionnaires. Mean follow-up was 5.9 years (range, 3.1-9.7 years). KOOS scores at follow-up in the isolated PCL group by subscale were 74 (symptoms), 76 (pain), 80 (activities of daily living), 55 (sport), and 55 (quality of life). Scores for patients in the multiligament group were 73 (symptoms), 79 (pain), 82 (activities of daily living), 53 (sport), and 56 (quality of life). Tegner scores were 4.5 and 4.4, respectively, and subjective IKDC scores were 63.8 and 65.0. The mean side-to-side difference in knee laxity was 2.7 mm in the isolated PCL group compared with 2.8 mm in the multiligament group. At 1-year follow-up there were significant differences in KOOS outcome scores between the isolated PCL subgroup and the multiligament subgroup, but no differences at final follow-up. Twelve patients (5%) had PCL revision surgery within the follow-up period.

Conclusion:

Despite the type of injury, there were only minor differences in knee laxity and subjective outcome scores between the isolated PCL group and the multiligament group. The overall revision rate in this study was 5.2%.

Clinical assessment of antero-medial rotational knee laxity: a systematic review

PURPOSE

To inventory the examination methods available to assess antero-medial rotational laxity (AMRL) of the knee following medial collateral ligament injury.

METHODS

Searches were conducted in accordance with the PRISMA guidelines and using four online databases: WEB OF SCIENCE, MEDLINE, EMBASE, and AMED. The Critical Appraisal Skills Programme guidelines for Diagnostic Test Studies were used for the quality assessment of the articles.

RESULTS

A total of 2241 articles were identified from the database searches. From this, four articles were included in the final review. All were case-control studies, considered a combined ACL/MCL injury and had small study populations. Specialised equipment was required in all studies, and one needed additional imaging support before measurements could be taken. Two employed commercially available measuring equipment as part of the assessment process.

CONCLUSION

Clinical assessment of AMRL in relation to a MCL injury remains challenging. Although methods have been developed to support clinical examination, they are limited by a number of factors, including the need for additional time in the clinical environment when setting up equipment, the need for specific equipment to produce and measure rotational movement and imaging support. In addition, there are patient safety concerns from the repeated imaging. A reliable and valid clinical examination remains to be found to truly assess antero-medial rotational laxity of the knee.

LEVEL OF EVIDENCE

IV.

Biomechanical evaluation of knee endpoint during anterior tibial loading: Implication for physical exams

BACKGROUND

Physical exams that apply anterior tibial loads are typically used to evaluate knees with anterior cruciate ligament (ACL) injuries. The amount of anterior tibial translation that occurs during these exams can be difficult to assess due to a "soft" endpoint. Therefore, the objective of this study is to determine the biomechanical characteristics of the endpoint for the intact and ACL deficient knee using quantitative criteria.

METHODS

Eight porcine knees were tested using a robotic testing system. An 89N anterior tibial load was applied to the intact and ACL deficient knee at 30°, 45°, 60° and 75° of flexion. The stiffness of the toe and linear regions was determined from the load-translation curve. The width of the transition region was defined by the distance between the points where the best-fit lines used to define the stiffness of the toe and linear regions diverged from the load-translation curve.

RESULTS

Stiffness of the toe and linear regions significantly decreased after transecting the ACL at all flexion angles (71-85% and 38-62%, respectively). Width of the transition region was significantly increased in the ACL deficient knee at all flexion angles (approximately four to five times and four to nine times, respectively).

CONCLUSIONS

The novel quantitative criteria developed in this study have the potential to be deployed in clinical practice by coupling them with data from knee arthrometers that are commonly used in clinical practice. Thus, additional information from the load-translation curve can be provided to improve the diagnosis of ACL injury.

Associated lateral/medial knee instability and its relevant factors in anterior cruciate ligament-injured knees

BACKGROUND

Associations of lateral/medial knee instability with anterior cruciate ligament (ACL) injury have not been thoroughly investigated. The purposes of this study were to investigate whether lateral/medial knee instability is associated with ACL injury, and to clarify relevant factors for lateral/medial knee instability in ACL-injured knees.

METHODS

One hundred and nineteen patients with unilateral ACL-injured knees were included. Lateral/medial knee instability was assessed with varus/valgus stress X-ray examination for both injured and uninjured knees by measuring varus/valgus angle, lateral/medial joint opening, and lateral/medial joint opening index. Manual knee instability tests for ACL were evaluated to investigate associations between lateral/medial knee instability and anterior and/or rotational instabilities. Patients' backgrounds were evaluated to identify relevant factors for lateral/medial knee instability. Damage on the lateral collateral ligament (LCL) on MRI was also evaluated.

RESULTS

All parameters regarding lateral knee instability in injured knees were significantly greater than in uninjured knees. There were significant correlations between lateral knee instability and the Lachman test as well as the pivot shift test. Patients with LCL damage had significantly greater lateral joint opening than those without LCL damage on MRI. Sensitivity of LCL damage on MRI to lateral joint opening was 100%, while its specificity was 36%. No other relevant factors were identified. In medial knee instability, there were also correlations between medial knee instability and the Lachman test/pivot shift test. However, the correlations were weak and other parameters were not significant.

CONCLUSIONS

Lateral knee instability was greater in ACL-deficient knees than in uninjured knees. Lateral knee instability was associated with ACL-related instabilities as well as LCL damage on MRI, whereas MRI had low specificity to lateral knee instability. On the other hand, the association of medial knee instability on ACL-related instability was less than that of lateral knee instability.

LEVELS OF EVIDENCE

Level IV, case series with no comparison group.

Twenty-Year Outcome of a Longitudinal Prospective Evaluation of Isolated Endoscopic Anterior Cruciate Ligament Reconstruction With Patellar Tendon or Hamstring Autograft

BACKGROUND

Long-term prospective studies of isolated endoscopic anterior cruciate ligament (ACL) reconstruction are limited and may include confounding factors.

PURPOSE

This study aimed to compare the outcomes of isolated ACL reconstruction using the patellar tendon (PT) autograft and the hamstring (HT) autograft in 180 patients over 20 years.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A total of 180 participants undergoing isolated ACL reconstruction between 1993 and 1994 were prospectively recruited. Evaluation was performed at 1, 2, 5, 7, 10, 15, and 20 years after surgery and included the International Knee Documentation Committee (IKDC) knee ligament evaluation with radiographic evaluation, KT-1000 arthrometer side-to-side difference, and subjective scores.

RESULTS

Over 20 years, there were 16 patients (18%) and 9 patients (10%) with an ACL graft rupture in the HT and PT groups, respectively (P = .13). ACL graft rupture was associated with male sex (odds ratio [OR], 3.9; P = .007), nonideal tunnel position (OR, 3.6; P = .019), and age <18 years at the time of surgery (OR, 4.6; P = .003). The odds of a contralateral ACL rupture were increased in patients with the PT graft compared with patients with the HT graft (OR, 2.2; P = .02) and those aged <18 years at the time of surgery (OR, 3.4; P = .001). The mean IKDC scores at 20-year follow-up were 86 and 89 for the PT and HT groups, respectively (P = .18). At 20 years, 53% and 57% of the PT and HT groups participated in strenuous or very strenuous activities (P = .55), kneeling pain was present in 63% and 20% of the PT and HT groups (P = .018), and radiographic osteoarthritic change was found in 61% and 41% of the PT and HT groups (P = .008), respectively.

CONCLUSION

Compared with patients who received the HT graft, patients who received the PT graft had significantly worse outcomes with regard to radiologically detectable osteoarthritis, kneeling pain, and contralateral ACL injury. At 20-year follow-up, both HT and PT autografts continued to provide good subjective outcomes and objective stability. However, further ACL injury is common, particularly in male individuals, younger patients, and those with tunnel malposition.

The Restoration of Passive Rotational Tibio-Femoral Laxity after Anterior Cruciate Ligament Reconstruction

While the anterior cruciate ligament (ACL) is considered one of the most important ligaments for providing knee joint stability, its influence on rotational laxity is not fully understood and its role in resisting rotation at different flexion angles in vivo remains unknown. In this prospective study, we investigated the relationship between in vivo passive axial rotational laxity and knee flexion angle, as well as how they were altered with ACL injury and reconstruction. A rotometer device was developed to assess knee joint rotational laxity under controlled passive testing. An axial torque of ±2.5Nm was applied to the knee while synchronised fluoroscopic images of the tibia and femur allowed axial rotation of the bones to be accurately determined. Passive rotational laxity tests were completed in 9 patients with an untreated ACL injury and compared to measurements at 3 and 12 months after anatomical single bundle ACL reconstruction, as well as to the contralateral controls. Significant differences in rotational laxity were found between the injured and the healthy contralateral knees with internal rotation values of 8.7°±4.0° and 3.7°±1.4° (p = 0.003) at 30° of flexion and 9.3°±2.6° and 4.0°±2.0° (p = 0.001) at 90° respectively. After 3 months, the rotational laxity remained similar to the injured condition, and significantly different to the healthy knees. However, after 12 months, a considerable reduction of rotational laxity was observed towards the levels of the contralateral controls. The significantly greater laxity observed at both knee flexion angles after 3 months (but not at 12 months), suggests an initial lack of post-operative rotational stability, possibly due to reduced mechanical properties or fixation stability of the graft tissue. After 12 months, reduced levels of rotational laxity compared with the injured and 3 month conditions, both internally and externally, suggests progressive rotational stability of the reconstruction with time.

Emerging Updates on the Posterior Cruciate Ligament: A Review of the Current Literature

The posterior cruciate ligament (PCL) is recognized as an essential stabilizer of the knee. However, the complexity of the ligament has generated controversy about its definitive role and the recommended treatment after injury. A proper understanding of the functional role of the PCL is necessary to minimize residual instability, osteoarthritic progression, and failure of additional concomitant ligament graft reconstructions or meniscal repairs after treatment. Recent anatomic and biomechanical studies have elucidated the surgically relevant quantitative anatomy and confirmed the codominant role of the anterolateral and posteromedial bundles of the PCL. Although nonoperative treatment has historically been the initial treatment of choice for isolated PCL injury, possibly biased by the historically poorer objective outcomes postoperatively compared with anterior cruciate ligament reconstructions, surgical intervention has been increasingly used for isolated and combined PCL injuries. Recent studies have more clearly elucidated the biomechanical and clinical effects after PCL tears and resultant treatments. This article presents a thorough review of updates on the clinically relevant anatomy, epidemiology, biomechanical function, diagnosis, and current treatments for the PCL, with an emphasis on the emerging clinical and biomechanical evidence regarding each of the treatment choices for PCL reconstruction surgery. It is recommended that future outcomes studies use PCL stress radiographs to determine objective outcomes and that evidence level 1 and 2 studies be performed to assess outcomes between transtibial and tibial inlay reconstructions and also between single- and double-bundle PCL reconstructions.

The Supine Internal Rotation Test: A Pilot Study Evaluating Tibial Internal Rotation in Grade III Posterior Cruciate Ligament Tears

Background:

Biomechanical studies have reported that the posterior cruciate ligament (PCL) functions as a restraint against excessive tibial internal rotation at higher degrees of knee flexion.

Purpose:

To investigate the use of a supine internal rotation (IR) test for the diagnosis of grade III PCL injuries. The hypothesis was that internal rotation would be greater in patients with grade III PCL injuries compared with other knee injuries and that the supine IR test would demonstrate excellent diagnostic accuracy.

Study Design:

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

Methods:

A consecutive series of 309 patients underwent arthroscopic and/or open knee ligament reconstruction surgery. Seven patients were excluded based on the inability to perform a side-to-side comparison of internal rotation. Tibial internal rotation was assessed bilaterally on 302 patients during examination under anesthesia by a single orthopaedic surgeon measuring tibial tubercle excursion (mm) while applying internal rotation torque. Internal rotation was graded from 0 to 4 at 60°, 75°, 90°, 105°, and 120° of knee flexion. Data were collected and stored prospectively. The optimal threshold for the supine IR test was chosen based on maximization of the Youden index. Diagnostic accuracy parameters were calculated. Multiple logistic regression models were constructed to assess the influence of other knee pathologies on diagnostic accuracy.

Results:

Examination of the 22 PCL-deficient knees demonstrated an increase in tibial internal rotation at 60°, 75°, 90°, 105°, and 120° of knee flexion. The supine IR test had a sensitivity of 95.5%, a specificity of 97.1%, a positive predictive value of 72.4%, and a negative predictive value of 99.6% for the diagnosis of grade III PCL injuries. Posterolateral corner injury had a significant interaction with the supine IR test, increasing its sensitivity and decreasing its specificity.

Conclusion:

PCL-deficient knees demonstrated an increase in the side-to-side difference in tibial internal rotation compared with other knee pathologies. The supine IR test offers high sensitivity and specificity for grade III PCL injuries and may represent a useful adjunct for diagnosing PCL injuries.

Posterior tibial translation resulting from the posterior drawer manoeuver in cadaveric knee specimens: a systematic review

PURPOSE

The purpose of this systematic review of cadaver-based biomechanical studies is to accurately quantify how much posterior tibial translation occurs during posterior drawer testing in normal and PCL-deficient knees.

METHODS

A search of the electronic databases, MEDLINE and EMBASE, was performed to identify relevant cadaveric studies that reported posterior tibial translation during posterior drawer testing. Studies were combined to determine overall increase in posterior tibial translation after PCL sectioning at 90° of flexion. Methodological quality of included studies was assessed by two reviewers using a novel clinometric tool. An intraclass correlation coefficient with 95 % confidence intervals (CIs) was used to determine agreement between reviewers on quality scores.

RESULTS

Combined analysis of 244 cadaveric specimens from 23 studies in which the PCL was sectioned yielded a mean net increase in tibial translation of 10.7 mm (95 % CI 9.68-11.8) with posterior drawer testing. Posterior tibial translation among cadaveric specimens with no disruption to any ligamentous structures was found to be 5.4 mm (95 % CI 4.3-6.6).

CONCLUSIONS

Cadaveric data support previous study findings of >8 mm of posterior tibial translation on stress radiographs being indicative of isolated PCL insufficiency. Use of fixed reference points and strict control of tibial rotation are imperative to ensure accurate results in cadaveric studies and in the clinical setting when performing the posterior drawer examination.

LEVEL OF EVIDENCE

III.

Anteromedial rotatory laxity

This paper describes anteromedial rotatory laxity of the knee joint. Combined instability of the superficial MCL and the structures of the posteromedial corner is the pathological background anteromedial rotatory laxity. Anteromedial rotatory instability is clinically characterized by anteromedial tibial plateau subluxation anterior to the corresponding femoral condyle. The anatomical and biomechanical background for anteromedial laxity is presented and related to the clinical evaluation, and treatment decision strategies are mentioned. A review of the clinical studies that address surgical treatment of anteromedial rotatory instability including surgical techniques and clinical outcomes is presented. Level of evidence V.

An analysis of normative data on the knee rotatory profile and the usefulness of the Rotatometer, a new instrument for measuring tibiofemoral rotation: the reliability of the knee Rotatometer

PURPOSE

This study proposes a simple and noninvasive instrument called the "Rotatometer" to measure tibiofemoral rotation and investigates its clinical applicability to the assessment of static rotational knee laxity.

METHODS

The degree of tibiofemoral rotation was measured for a sample of 94 healthy volunteers with 188 knees by using the Rotatometer. The measurement was made by two independent and blinded examiners in three sessions at one-month intervals. The normative rotational profile and its relationship with gender and age were evaluated, and inter-observer reliability and intra-observer reliability were calculated.

RESULTS

Males showed 62° ± 5° of external rotation, whereas females, 64° ± 5°. Males showed 44° ± 5° of internal rotation, whereas females, 49° ± 4°. Females showed significantly higher degrees of rotation than males. Tibiofemoral rotation was not correlated with age, and external rotation and internal rotation had a moderate positive relationship. Inter-observer reliability ranged from 0.84 to 0.91 for external rotation and 0.90 to 0.95 for internal rotation, and intra-observer reliability ranged from 0.69 to 0.89 for external rotation and 0.87 to 0.95 for internal rotation.

CONCLUSIONS

The results suggest the Rotatometer to be a simple and noninvasive device with high inter- and intra-observer reliability. The device can provide a normative rotational profile for reference purposes and thus can be used to determine the preoperative and postoperative rotational status of knees with anterior cruciate ligament injuries and compare results from different reconstruction techniques.

Twenty-year outcomes of a longitudinal prospective evaluation of isolated endoscopic anterior cruciate ligament reconstruction with patellar tendon autografts

BACKGROUND

Long-term prospective follow-up studies of single-incision endoscopic anterior cruciate ligament (ACL) reconstruction are limited and may include confounding factors.

PURPOSE

This longitudinal prospective study reports the outcomes of isolated ACL reconstruction using middle-third patellar tendon autografts in 90 patients over 20 years.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Between January 1993 and April 1994, a total of 90 patients met study inclusion criteria: evaluation at 1, 2, 3, 4, 5, 7, 10, 15, and 20 years after surgery. Exclusion criteria were associated ligamentous injuries requiring surgery, previous meniscectomy or meniscal injuries requiring more than one-third meniscectomy, chondral injuries, and an abnormal contralateral knee.

RESULTS

At 20 years, 32 (36%) patients had sustained another ACL injury: 8 (9%) to the index limb and 27 (30%) to the contralateral limb (3 injuring both knees). The mean International Knee Documentation Committee (IKDC) score was 86. Of the patients, 50% participated in strenuous/very strenuous activities, and kneeling pain was present in 63%. Radiographic degenerative change was found in 61%; 20% had IKDC grade C, and 0% had grade D. The IKDC clinical examination revealed that 95% had a normal/nearly normal knee. Significant sex differences existed: when compared with male patients, female patients were less likely to reinjure the reconstructed ACL (18% vs 2%, respectively; P = .01), reported poorer IKDC subjective scores (90 vs 83, respectively; P = .03), had more activity-related pain (20% vs 57%, respectively; P = .02), and were less likely to participate in strenuous activities (66% vs 35%, respectively; P = .009). ACL graft survival was not related to age. Patients <18 years old had an increased odds ratio (3.2) for rupturing the contralateral ACL. A coronal graft angle <17° increased the risk of failure compared with an angle >17° (77% vs 96% survival, respectively) by a factor of 8.5.

CONCLUSION

Injuries more commonly occurred in the contralateral ACL than in the reconstructed ACL graft, and the most significant predictor of a contralateral ACL injury was age <18 years. The most significant predictor of an ACL graft rupture was a coronal graft angle <17°. Female patients had lower rerupture rates, poorer subjective scores, and decreased participation in strenuous activities, putting the graft at a lower risk of failure. Kneeling pain remained persistent over 20 years. Radiographic osteoarthritis was evident in 61% of patients, but symptomatic osteoarthritic symptoms were rarely reported.

Knee instability in patients with traumatic knee disorders: a cohort study in primary care

BACKGROUND

There is a lack of knowledge about the course of knee instability in patients with traumatic knee disorders.

OBJECTIVE

The aim of the study was to determine the course of traumatic knee instability during 1-year follow-up and to observe the treatment of knee instability by GPs.

METHODS

Patients (n = 134) aged 18-65 years with traumatic knee disorders who consulted their GP within 5 weeks after trauma were enrolled in a prospective cohort study. Data were collected at baseline and at 3, 6 and 12 months follow-up. Magnetic resonance imaging (MRI) and physical examination of the knee were performed at baseline and at 1-year follow-up.

RESULTS

At baseline, 28% of the 134 patients had no knee instability, 17% reported knee instability (according Lysholm score), 31% tested positive on knee instability (according Lachman test) and 24% both self-reported and tested positive on instability of the knee. At baseline and at 1-year follow-up, no clear differences between MRI findings, treatment and course of the defined groups of knee instability were found. At 1-year follow-up, patients with both self-reported and tested positive seemed to have worse outcomes.

CONCLUSION

During 1-year follow-up, it was unclear if there were differences regarding course, treatment and MRI findings of the knee between no instability and the three defined knee instability groups. Statistical power was lacking in the comparisons made and therefore studies with more patients are needed.

A model of the soft tissue artefact rigid component

When using stereophotogrammetry and skin-markers, the reconstruction of skeletal movement is affected by soft-tissue artefact (STA). This may be described by considering a marker-cluster as a deformable shape undergoing a geometric transformation formed by a non-rigid (change in size and shape) and a rigid component (translation and rotation displacements). A modal decomposition of the STA, relative to an appropriately identified basis, allows the separation of these components. This study proposes a mathematical model of the STA that embeds only its rigid component and estimates the relevant six mode amplitudes as linear functions of selected proximal and distal joint rotations during the analysed task. This model was successfully calibrated for thigh and shank using simultaneously recorded pin- and skin-marker data of running volunteers. The root mean square difference between measured and model-estimated STA rigid component was 1.1(0.8)mm (median (inter-quartile range) over 3 subjects × 5 trials × 33 markers coordinates), and it was mostly due to the wobbling not included in the model. Knee joint kinematics was estimated using reference pin-marker data and skin-marker data, both raw and compensated with the model-estimated STA. STA compensation decreased inaccuracy on average from 6% to 1% for flexion/extension, from 43% to 18% for the other two rotations, and from 69% to 25% for the linear displacements. Thus, the proposed mathematical model provides an STA estimate which can be effectively used within optimal bone pose and joint kinematics estimators for artefact compensation, and for simulations aimed at their comparative assessments.

Comparative reproducibility of TELOS™ and GNRB® for instrumental measurement of anterior tibial translation in normal knees

BACKGROUND

TELOS™ is among the reference tools for the instrumental measurement of anterior tibial translation during the initial work-up and follow-up of patients with injuries to the anterior cruciate ligament (ACL). GRNB(®) is a non-irradiating but recently developed tool for which only limited data are available.

HYPOTHESIS

The GRNB(®) offers better reproducibility than TELOS™ for measuring anterior tibial translation without rotation in normal knees.

MATERIAL AND METHODS

We retrospectively evaluated instrumental laxity measurements in normal knees. Data were available for 60 TELOS™ measurements (9kg load) and 57 GNRB(®) measurements (89N and 134N loads). For each instrument, we compared the absolute variation in anterior tibial translation between two measurements performed 6 months apart. For each GNRB(®) measurement, patellar pressure was recorded.

RESULTS

No significant differences were found between mean (± SD) variations in translation between the two instruments. A greater than 2.5mm variation between the two measurements was significantly more common with TELOS™ than with GRNB(®) (P<0.05, Chi(2) test). GRNB(®) translation values did not correlate with patellar pressure.

DISCUSSION

The GNRB(®) device offers greater reproducibility than TELOS™ when used to quantitate anterior tibial translation. The limited sample size may have prevented the detection of a significant difference between mean values. In addition, disadvantages of the TELOS™ include radiation exposure of the patient, operator-dependency of measurements made on the radiographs, and absence of a biofeedback system to limit hamstring contraction. GNRB(®) does have hamstring contraction biofeedback control but uses another parameter, namely, patellar pressure, for which the optimal value is unknown. Quadriceps and hamstring co-contraction induced by excessive patellar pressure may influence anterior tibial translation. The optimal patellar pressure value needs to be determined.

In situ forces and length patterns of the fibular collateral ligament under controlled loading: an in vitro biomechanical study using a robotic system

PURPOSE

The aim of this study was to determine the in situ forces and length patterns of the fibular collateral ligament (FCL) and kinematics of the knee under various loading conditions.

METHODS

Six fresh-frozen cadaveric knees were used (mean age 46 ± 14.4 years; range 20-58). In situ forces and length patterns of FCL and kinematics of the knee were determined under the following loading conditions using a robotic/universal force-moment sensor testing system: no rotation, varus (10 Nm), external rotation (5 Nm), and internal rotation (5 Nm) at 0°, 15°, 30°, 60º, 90°, and 120° of flexion, respectively.

RESULTS

Under no rotation loading, the distances between the centres of the FCL attachments decreased as the knee flexed. Under varus loading, the force in FCL peaked at 15° of flexion and decreased with further knee flexion, while distances remained nearly constant and the varus rotation increased with knee flexion. Using external rotation, the force in the FCL also peaked at 15° flexion and decreased with further knee flexion, the distances decreased with flexion, and external rotation increased with knee flexion. Using internal rotation load, the force in the FCL was relatively small across all knee flexion angles, and the distances decreased with flexion; the amount of internal rotation was fairly constant.

CONCLUSIONS

FCL has a primary role in preventing varus and external rotation at 15° of flexion. The FCL does not perform isometrically following knee flexion during neutral rotation, and tibia rotation has significant effects on the kinematics of the FCL. Varus and external rotation laxity increased following knee flexion. By providing more realistic data about the function and length patterns of the FCL and the kinematics of the intact knee, improved reconstruction and rehabilitation protocols can be developed.

Can physical examination predict the intraarticular tear pattern of the anterior cruciate ligament?

PURPOSE

We evaluated the correlation between physical examinations and the tear patterns of the anterior cruciate ligament (ACL).

MATERIALS AND METHODS

From January 2003 to May 2007, we reviewed 201 cases of ACL rupture, diagnosed by MRI. Two orthopaedic surgeons (a fellow and a senior surgeon) evaluated the instability of the knee under anaesthesia: physical examinations were the anterior draw test (AD), Lachman test (LT), and pivot shift test (PT). By describing the rupture pattern and the site of the anteromedial (AMB) and posterolateral bundle (PLB) during arthroscopic examination, we analysed the correlation between the physical examination under anaesthesia and arthroscopic findings.

RESULTS

In terms of the arthroscopic findings, rupture of the PLB was seen in 83 cases (41.3 %), of the AMB in 24 cases (11.9 %), and of both bundles in 94 cases (46.8 %). The kappa values for the physical examinations between the examiners were 0.963 (AD), 0.92 (LT), and 0.865 (PT). AD and LT above grade 2 did not differ significantly according to the pattern of rupture, but a PT above grade 2 was significantly different in ruptured PLB versus complete rupture.

CONCLUSIONS

A PT of more than grade 2 is a reliable physical examination for prediction of ruptured PLB or complete rupture.

Impact of Patient Sex on Clinical Outcomes: Data From an Anterior Cruciate Ligament Reconstruction Registry, 2008-2013

Background:

The Combined Quality Care Anterior Cruciate Ligament registry provides data for clinical research regarding primary anterior cruciate ligament (ACL) surgery.

Purpose:

To explore the data with regard to the clinical outcomes between sexes after ACL reconstruction in a Dutch population.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Data involving patients diagnosed with an ACL tear and eligible for surgery were recorded. Isokinetic muscle strength, functional muscle performance, and anterior-posterior translation of the knee joint were documented preoperatively and at 3, 6, 9, and 12 months postoperatively. Patients completed the Knee Injury and Osteoarthritis Outcome Score (KOOS), Lysholm, and Tegner rating scales during each examination using a web-based questionnaire.

Results:

Approximately 90% of ACL injuries occurred during sport activities. The mean (SD) age at surgery was 28 (11) years for both men and women, and the majority of patients were treated with hamstring tendon autografts (94%). Four percent received bone–patellar tendon–bone autografts, and 2% of the patients received other grafts. Preoperatively, the KOOS, Lysholm, and Tegner scores were significantly higher in males. Twelve months postoperatively, both sexes showed comparable isokinetic strength (P = .336), knee laxity (P = .680), and hop test for distance (P = .122) when comparing the injured with the uninjured side. Self-reported knee function was comparable between sexes as assessed by the KOOS (P = .202), Lysholm (P = .872), and Tegner (P = .767) questionnaires during the 12-month follow-up.

Conclusion:

One year after ACL surgery, all patients had improved greatly, showing only minor differences between sexes. The male group showed slightly better results when evaluating self-reported knee questionnaires. Comparable outcomes and knee function between sexes can therefore be presumed with patients who are treated with hamstring tendon autografts in a Dutch population.

Clinical Relevance:

These results can be used during the clinical evaluation of patients who are eligible for ACL reconstruction.