Contralateral Uninjured Knee Research Articles

Anterior cruciate ligament injury and age affect knee cartilage T2 but not thickness

ObjectiveTo investigate the effect of unilateral anterior cruciate ligament (ACL) injury on cartilage thickness and composition, specifically laminar transverse relaxation time (T2) by magnetic resonance imaging (MRI), in younger and older participants and to compare within-person side differences in these parameters between ACL-injured and healthy controls. DesignQuantitative double-echo steady-state (qDESS) 3 Tesla MRI-sequences were acquired in both knees of 85 participants in four groups: 20–30 years: healthy, HEA20–30, n=24; ACL-injured, ACL20–30, n=23; 40–60 years: healthy, HEA40–60, n=24; ACL-injured, ACL40–60, n=14 (ACL injury 2–10 years prior to study inclusion). Weight-bearing femorotibial cartilages were manually segmented; cartilage T2 and thickness were computed using custom software. Mean and side difference in subregional cartilage thickness, superficial and deep cartilage T2 were compared within and between groups using non-parametric statistics. ResultsCartilage thickness did not differ within or between groups. Only the side difference in medial femorotibial cartilage thickness was greater in ACL20–30 than in HEA20–30. Deep zone T2 was longer in the ACL-injured than in the contralateral uninjured knees and than in healthy controls, especially in the lateral compartment. Most ACL-injured participants had side differences in femorotibial deep zone T2 above the threshold derived from controls. ConclusionIn the ACL-injured knee, early compositional differences in femorotibial cartilage (T2) appear to occur in the deep zone and precede cartilage thickness loss. These results suggest that monitoring laminar T2 after ACL injury may be useful in the diagnosing and monitoring early articular cartilage changes.

Using 3D MRI Bone Shape to Predict Pre-Osteoarthritis of the Knee 2 Years After Anterior Cruciate Ligament Reconstruction

Background: Anterior cruciate ligament (ACL) injury increases risks for osteoarthritis (OA), a poorly modifiable and disabling condition. Joint changes of potentially reversible pre-OA have been described just 2 years after ACL reconstruction (ACLR) when early bone shape changes have also been reported. Purpose: This study evaluates relationships between interlimb differences in tibiofemoral bone shape derived from statistical shape modeling (SSM) of magnetic resonance imaging (MRI) and participant factors on patient-reported outcomes 2 years after unilateral ACLR. Study Design: Cross-sectional study; Level of evidence, 3. Methods: SSM-derived tibiofemoral bone shape and subchondral bone area were assessed from bilateral knee MRI scans of 72 participants with unilateral ACLR (mean age, 34 ± 11 years; 32 women) and compared with a reference cohort of 398 older individuals without OA (mean age, 50 ± 3 years; 213 women). Multivariable logistic regression models examined relationships between participant and surgical factors with interlimb differences in bone shapes or subchondral bone areas. Relationships between patient-reported outcomes and the interlimb differences in bone shape and subchondral area were examined using similar models. Results: Bone shape scores and subchondral bone areas were greater (more OA-like) in ACLR knees than uninjured contralateral knees in every bone metric tested (P≤ .001). Interlimb differences in femur shape scores of participants with ACLR were 65% greater (P < .001) than those of the significantly older reference cohort. Taller height, medial meniscal tears, and decreasing age were associated with larger interlimb differences in shape scores and subchondral areas (P < .05). Bone–patellar tendon–bone (BPTB) autograft recipients demonstrated greater interlimb subchondral area differences compared with allograft recipients (P < .05). Interlimb differences for hamstring autograft recipients did not differ from those with BPTB or allograft. Greater interlimb differences in medial femur subchondral areas were associated with worse patient-reported Knee injury and Osteoarthritis Outcome Score Symptoms (R = 0.27; P = .040). Conclusion: Even in the absence of radiographic OA, just 2 years after unilateral ACLR patients showed greater bone shape scores and subchondral areas consistent with pre-OA in their ACLR knees. Furthermore, greater medial femur bone areas were weakly associated with worse symptoms. Patients who are younger, are taller, have meniscal tears, or have BPTB grafts may be at increased risk for bony asymmetries 2 years after ACLR.

Role of MRI to Determine Impact on Contralateral ACL/Meniscal Damage Secondary to Unilateral Traumatic Knee Injury in Adults

Background: Knee injuries are one of the most common sports injuries and may cause chronic functional impairment. During a study in emergency department approximately 50% of injuries are caused by sports activities, with majority of the cases comprising of knee soft tissue injuries. The most common modality to diagnose musculoskeletal injury is magnetic resonance imaging nowadays. Knee injuries are one of the most frequently overlooked injuries and cause long term functional impairment. MRI provides the most effective and comprehensive imaging assessment of the knee joint and adjacent structures. Objective: To determine the significance of Magnetic resonance imaging (MRI) of contralateral uninjured knee in suspected meniscal/ACL injury of traumatic patients. Study Design: Prospective study. Settings: Radiology Department of Jinnah Postgraduate Medical Center (JPMC), Karachi Pakistan. Duration: January 2018 to December 2021. Methods: Patients aged 18 years or older who presented with a unilateral traumatic knee injury requiring medical evaluation and treatment and who underwent MRI evaluations for both the injured knee (ipsilateral) and the contralateral knee (opposite side) as part of their medical assessment were included. After taking informed consent, all patients underwent magnetic resonance imaging (MRI) examinations of both their affected (ipsilateral) and non-affected (contralateral) knee joints. These MRI findings were subjected to rigorous statistical analysis, which included comparisons between the affected and non-affected knees. Self-made proforma was used for the data collection. Results: According to our inclusion criteria, we identified 45 patients to participate in the study. Amongst these 82% of the patients were male and 17% were females, ratio between the male and female is 4.6:1. Mean age of the participants was found to be 38.64±14.4 years. Upon analysis, 62.2% of the patients had meniscal injury associated with ACL/PCL damage. While MRI findings were compared with contralateral normal side and found meniscal injury in 17(37.8%) cases, followed ACL/PCL injury 7(15.6%) and ACL/PCL injury associated meniscal injury ± effusion 7(15.6%) was (p = 0.004). Conclusion: MRI has proven to be a valuable imaging modality for identifying ligament tears and meniscal injuries of the knee joint in patients suspected of having meniscal/ACL injuries due to trauma. It not only assists in diagnosis but also provides valuable insights into the complexity of knee trauma.

The use of ultrasonography as an effective screening tool for chronic posterior cruciate ligament injuries

PurposeWe aimed to explore the applicability and validity of ultrasonography for diagnosing chronic posterior cruciate ligament (PCL) injuries.MethodsPCL thickness was measured at 2 cm proximal to the tibia insertion site. Using the same ultrasonography image, the angle tangent to the PCL from the tibia insertion site was also measured. These data were analyzed by plotting the receiver operating curve (ROC), and the sensitivity and specificity were calculated according to the optimal cut-off point. Ultrasonography data from the PCLinjured knee were compared with those from the contralateral uninjured knee of the same patient.ResultsTwelve men and six women, with a mean age of 28.8 ± 14.0 years, were included in this study. The mean time from injury to medical examination was 10.0 ± 6.7 months. The mean thickness of the PCL was 8.1 ± 1.9 mm on the affected side and 5.8 ± 1.2 mm on the uninjured side, with the affected side being significantly thicker. ROC analysis revealed that the optimal cut-off value for the thickness of chronic PCL injuries was 6.5 mm (sensitivity 83.3%, specificity 77.8%, area under the curve [AUC] = 0.87). The optimal cut-off value for the angle was 20° (sensitivity 88.9%, specificity 94.4%, AUC = 0.96).ConclusionUltrasonography is useful as a screening tool for chronic PCL injuries. The optimal cut-off point was 6.5 mm for thickness and 20° for angle.Level of evidenceIV.

Acute Bone Loss and Infrapatellar Fat Pad Fibrosis in the Knee After an In Vivo ACL Injury in Adolescent Mice

Background: Young patients are 6 times more likely than adults to have a primary anterior cruciate ligament (ACL) graft failure. Biological factors (ie, tunnel osteolysis) may account for up to a third of these failures. Previous evaluations of patient ACL explants indicated significant bone loss within the entheseal regions. However, it remains unknown if the degree of bone loss within the ACL insertion regions, wherein ACL grafts are fixated, exceeds that of the femoral and tibial condylar bone. Hypothesis: Bone loss in the mineralized matrices of the femoral and tibial ACL entheses is distinct from that clinically reported across the whole knee after injury. Study Design: Controlled laboratory study. Methods: We developed a clinically relevant in vivo mouse ACL injury model to cross-sectionally track the morphological and physiological postinjury changes within the ACL, femoral and tibial entheses, synovial joint space, and load-bearing epiphyseal cortical and trabecular bone components of the knee joint. Right ACLs of 10-week-old C57BL/6J female mice (N = 75) were injured in vivo with the contralateral ACLs serving as controls. Mice were euthanized at 1, 3, 7, 14, or 28 days after injury (n = 12/cohort). Downstream analyses included volumetric cortical and trabecular bone analyses and histopathologic assessments of the knee joint after injury. Gait analyses across all time points were also performed (n = 15 mice). Results: The majority of the ACL injuries in mice were partial tears. The femoral and tibial cortical bone volumes were 39% and 32% lower, respectively, at 28 days after injury than those of the uninjured contralateral knees (P < .01). Trabecular bone measures demonstrated little difference between injured and control knees after injury. Across all bone measures, bone loss was similar between the injured knee condyles and ACL entheses. There was also significant inflammatory activity within the knee after injury. By 7 days after injury, synovitis and fibrosis were sigificantly elevated in the injured knee compared with the controls (P < .01), which corresponded with significantly higher osteoclast activity in bone at this time point compared with the controls. This inflammatory response signficantly persisted throughout the duration of the study (P < .01). The hindlimb gait after injury deviated from normal, but mice habitually loaded their injured knee throughout the study. Conclusion: Bone loss was acute and persisted for 4 weeks after injury in mice. However, the authors’ hypothesis was not confirmed, as bone quality was not significantly lower in the entheses compared with the condylar bone regions after injury. With relatively normal hindlimb loading but a significant physiological response after injury, bone loss in this model may be driven by inflammation. Clinical Relevance: There is persistent bone resorption and fibrotic tissue development after injury that is not resolved. Inflammatory and catabolic activity may have a significant role in the postinjury decline of bone quality in the knee.

Tension Band Wiring of Patella Fractures: Mid-Term Radiological and Clinical Results

Objective: We aimed to share our radiological and clinical results with a mid-term follow-up on patella fractures treated with tension band wiring (TBW).&#x0D; Methods: Patients surgically treated with TBW for AO type 34-A1/C1/C2/C3 patella fractures between January 2013 and June 2021 at a level 1 trauma center were included. For radiological evaluation, radiographs obtained at the routine follow-up were analyzed for complications (such as nonunion, malunion, loss of reduction, malreduction, patella baja, elongated patella, implant failure), Insall-Salvati Index (ISI), and Patellar Morphology Ratio (PMR). The Knee Injury and Osteoarthritis Score (KOOS) was utilized for functional evaluation, which includes five subscales: pain, symptoms, activities of daily living (ADL), sports/recreation, and quality of life (QOL). The clinical assessment also included the range of motion (ROM), thigh circumference (TC), and complications such as implant irritation (II).&#x0D; Results: This study reviewed 42 eligible patients (10 females, 32 males) with a mean age of 42.6 ± 16.1 years and a mean follow-up of 35.4 ± 24.1 months. There were 28 patients (66.7%) with at least one complication (II: 66.7%, flexion deficit: 61.9%, malunion: 40.5%, elongated patella/patella baja: 16.7%). The reoperation rate was high at 69.1% due to the high implant removal rate for II. There were statistically significant differences between injured (I) and uninjured contralateral healthy knees (UI) in terms of mean KOOS subscale scores (symptoms: I: 72.3, UI: 89.8; pain: I: 70.4, UI: 89.4; ADL : I: 72.1, UI: 90; sports: I: 61.4, UI: 84.8; QOL: I: 67.9, UI: 86.2), mean flexion degrees (I: 126.2°, UI: 135.4°), mean ISI (I: 0.9, UI: 1.0), and mean PMR (I: 1.5, UI: 1.4) (all p &lt; 0.01). There was no difference in mean extension degrees and TC (all p &gt; 0.05). All fractures achieved union.&#x0D; Conclusion: Firstly, the mid-term clinical results of patellar fractures treated with TBW were significantly worse than the contralateral healthy knee; secondly, implant irritation, knee flexion deficit, malunion, and patella baja were the significant complications, and efforts should be made to manage these problems; thirdly, patellar fractures are susceptible to developing interesting cases of the elongated patella.

Anterior-cruciate-ligament reconstruction does not alter the knee-extensor moment arm during gait

BackgroundThe ability of the quadriceps muscles to extend the knee depends on the moment arm of the knee-extensor mechanism, which is described by the moment arm of the patellar tendon at the knee. The knee-extensor moment may be altered by a change in quadriceps force, a change in the patellar tendon moment arm (PTMA), or both. A change in quadriceps muscle strength after anterior-cruciate-ligament-reconstruction (ACLR) surgery is well documented, however, there is limited knowledge about how this procedure affects the PTMA. Research questionDoes ACLR surgery alter the moment arm of the knee-extensor mechanism during gait? MethodsWe measured the PTMA in both the ACLR knee and the uninjured contralateral knee in 10 young active individuals after unilateral ACLR surgery. Mobile biplane X-ray imaging was used to measure the three-dimensional positions of the femur, tibia and patella during level walking and downhill walking over ground. The PTMA was found from the location of the instantaneous axis of rotation at the knee and the line-of-action of the patellar tendon. ResultsThere was a small but statistically significant difference in the mean PTMA calculated over one cycle of level walking between the ACLR knee and the contralateral knee, with the mean PTMA in the ACLR knee being 1.5 mm larger (p < 0.01). In downhill walking, statistically significant differences were found in the range 15°– 25° of knee flexion, where the PTMA was 4.7 mm larger in the ACLR knee compared to the contralateral knee (p < 0.01). SignificanceSignificant differences were evident in the mean PTMA between the ACLR knee and the contralateral knee in both activities, however, the magnitudes of these differences were relatively small (range: 3–10%), indicating that ACLR surgery successfully restores the moment arm of the knee-extensor mechanism during dynamic activity.

Quantitative evaluation of the tibiofemoral joint cartilage by T2 mapping in patients with acute anterior cruciate ligament injury vs contralateral knees: results from the subacute phase using data from the NACOX study cohort

Immediate cartilage structural alterations in the acute phase after an anterior cruciate ligament (ACL) rupture may be a precursor to posttraumatic osteoarthritis (PTOA) development. Our aim was to describe changes in cartilage matrix in the subacute phase of the acutely ACL-injured knee compared to the contralateral uninjured knee. Participants (n=118) aged 15-40 years with an acute ACL injury were consecutively included in subacute phase after acute ACL-injury and underwent MRI (mean 29 days post trauma) of both knees. Mean T2 relaxation times, T2 spatial coefficient of variation and cartilage thickness were determined for different regions of the tibiofemoral cartilage. Differences between the acutely ACL-injured and uninjured knee were evaluated using Wilcoxon signed-rank test. T2 relaxation time in injured knees was increased in multiple cartilage regions from both medial and lateral compartment compared to contralateral knees, mostly in medial trochlea and posterior tibia (P-value<0.001). In the same sites of injured knees, we observed significantly thinner cartilage. Moreover, injured knees presented shorter T2 relaxation time in superficial cartilage on lateral central femur and trochlea (P-value<0.001), and decreased T2 spatial coefficient of variation in lateral trochlea and load bearing regions of medial-central femoral condyle and central tibia in both compartments. Small but statistically significant differences were observed in the subacute phase between ACL-injured and uninjured knee in cartilage T2 relaxation time and cartilage thickness. Future longitudinal observations of the same cohort will allow for better understanding of early development of PTOA. NCT02931084.

QUANTITATIVE EVALUATION OF THE TIBIOFEMORAL JOINT CARTILAGE BY T2 MAPPING IN PATIENTS WITH ACUTE ANTERIOR CRUCIATE LIGAMENT INJURY

Purpose: Immediate cartilage structural alterations in the acute phase after an anterior cruciate ligament (ACL) rupture may be a precursor to posttraumatic osteoarthritis (PTOA) development. Our aim was to describe structural and morphological cartilage parameters in the subacute phase of the acutely ACL-injured knee compared to the contralateral uninjured knee.

Independent changes in bone mineralized and marrow soft tissues following acute knee injury require dual-energy or high-resolution computed tomography for accurate assessment of bone mineral density and stiffness

Musculoskeletal injuries often induce local accumulation of blood and/or fluid within the bone marrow, which is detected on medical imaging as edema-like marrow signal intensities (EMSI). In addition to its biological effects on post-injury recovery, the displacement of low-attenuating, largely adipocytic marrow by EMSI may introduce errors into quantitative computed tomography (QCT) measurements of bone mineral density (vBMD) and resulting bone stiffness estimates from image-based finite element (FE) analysis. We aimed to investigate the impact of post-injury changes in marrow soft tissue composition on CT-based bone measurements by applying CT imaging at multiple spatial resolutions. To do so, dual energy QCT (DECT) material decomposition was used to detect EMSI in the tibiae of nineteen participants with a recent anterior cruciate ligament tear. We then measured bone density and FE-based apparent modulus within the EMSI region and in a matched volume in the uninjured contralateral knee. Three measurement methods were applied: 1.) standard, QCT density calibration and density-based FEM; 2.) a DECT density calibration that provides density measurements adjusted for marrow soft tissues; and 3.) high-resolution peripheral QCT (HR-pQCT) density and microFE analyses. When measured using standard, single-energy QCT, vBMD and apparent modulus were elevated in the EMSI compared to the contralateral. After adjusting for marrow soft tissue composition using DECT, these measurements were no longer different between the two regions. By allowing for high-resolution, localized density analysis, HR-pQCT indicated that trabecular tissue mineral density was 9 mgHA/cm3 lower, while density of marrow soft tissues was 18 mgHA/cm3 higher, in the EMSI than the contralateral region, suggesting that EMSI have opposite effects on the measured density of trabecular bone and the underlying soft marrow. Thus, after an acute injury, altered composition of marrow soft tissues may artificially inflate overall measurements of bone density and apparent modulus obtained using standard QCT. This can be corrected by accounting for marrow soft tissue attenuation, either by using DECT-based density calibration or HR-pQCT microFE and measurements of local density of trabeculae.

The Effect of Posterior Tibial Slope on the Risk of Revision Surgery After Anterior Cruciate Ligament Reconstruction

Background: A significant proportion of patients undergoing anterior cruciate ligament (ACL) reconstruction (ACLR) later experience graft failure. Some studies suggest an association between a steep posterior tibial slope (PTS) and graft failure. Purpose: To examine the PTS in a large cohort of patients about to undergo ACLR and to determine whether a steep PTS is associated with later revision surgery. Study Design: Case-control study; Level of evidence, 3. Methods: A retrospective review of a cohort undergoing isolated ACLR between 2002 and 2012 (with 8-19 years of follow-up) was conducted. Preoperative sagittal radiographs of knees in full extension were used for measurements of the PTS. There were 2 independent examiners who performed repeated measurements to assess the reliability of the method. Statistical analyses were performed to compare the PTS in the groups with and without later revision surgery. Results: A total of 728 patients, with a mean age of 28 years at the time of surgery, were included. Overall, 10% (n = 76) underwent revision surgery during the observation period. The group of injured knees had a significantly steeper PTS compared with the group of uninjured knees (9.5° vs 8.7°, respectively; P < .05). The mean PTS in the no revision group was 9.5° compared with 9.3° in the revision group (not significant). Dichotomized testing of revision rates related to PTS cutoff values of ≥10°, ≥12°, ≥14°, ≥16°, and ≥18° showed no association of PTS steepness (not significant) to graft failure. Patients with revision were younger than the ones without (mean age, 24 ± 8 vs 29 ± 10 years, respectively) and had a shorter time from injury to ACLR (mean, 14 ± 27 vs 24 ± 44 months, respectively) as well as a smaller graft size (8.2 vs 8.4 mm, respectively; P = .040). Conclusion: The current study did not find any association between a steep PTS measured on lateral knee radiographs and revision ACL surgery. However, a steeper PTS was seen in the group of injured knees compared with the group of uninjured (contralateral) knees. Independent of the PTS, younger patients, those with a shorter time from injury to surgery, and those with a smaller graft size were found to undergo revision surgery more often.

The Proximal Tibia Loses Bone Mineral Density After Anterior Cruciate Ligament Injury: Measurement Technique and Validation of a Quantitative Computed Tomography Method

PurposeTo develop a standardized method for tibial tunnel volumetric bone mineral density (BMD) analysis with quantitative computed tomography (qCT) using cadaveric specimens to provide validation of this technique on a healthy control population and to determine whether osteopenia occurs following an anterior cruciate ligament (ACL) injury.Methods: qCT was used to develop a volumetric BMD (mg/cm3) measurement technique throughout the region of a standard tibial tunnel. This method was applied to 90 lower extremities, including 10 matched cadaveric knees, 10 matched healthy knees, 25 ACL-injured knees, and 25 contralateral ACL-uninjured knees. The mean total and segmental (proximal, middle, and distal) tibial tunnel BMD were analyzed.ResultsThe mean entire tibial tunnel BMD measured 165.8 ± 30.5 mg/cm3 (cadaver), 255.9 ± 28.2 mg/cm3 (healthy control), 290.3 ± 36.4 mg/cm3 (ACL-injured), and 300.1 ± 35.1 (ACL-uninjured). Segmental tibial tunnel BMD demonstrated distal one-third segments as the greatest areas of BMD, followed by proximal one-third, and middle one-third for all cohorts with all pairwise comparisons (P < .001). The mean BMD was significantly greater in the uninjured extremity compared with the injured extremity in the entire tunnel (290.3 vs 300.1; P < .001), proximal (271.2 vs 279.1; P = .002), middle (167.6 vs 179.6; P < .001), and distal segments (432.7 vs 441.7; P = .004) at an average of 8 weeks following ACL injury.ConclusionsA standardized method to quantitatively measure the volumetric BMD within the region of a standard tibial tunnel for ACL reconstruction was successfully developed and validated. Significant osteopenia of the injured knee occurs following ACL injury when compared with the contralateral uninjured knee. This observation has potential clinical implications for ACL graft tibial fixation and healing.Level of EvidenceDescriptive diagnostic study, Level III.

Reliability of Anatomic Bony Landmark Localization of the ACL Femoral Footprint Using 3D MRI.

Background:Nonanatomic placement of anterior cruciate ligament (ACL) grafts is a leading cause of ACL graft failure. Three-dimensional (3D) magnetic resonance imaging (MRI) femoral footprint localization could enhance planning for an ACL graft's position.Purpose:To determine the intra- and interobserver reliability of measurements of the ACL femoral footprint position and size obtained from 3D MRI scans.Study Design:Cohort study; Level of evidence, 3.Methods:A total of 41 patients with complete ACL tears were recruited between November 2014 and May 2016. Preoperatively, a coronal-oblique proton-density fast spin echo 3D acquisition of the contralateral uninjured knee was obtained along the plane of the ACL using a 1.5T MRI scanner. ACL footprint parameters were obtained independently by 2 musculoskeletal radiologists (observers A and B). The distal and anterior positions of the center of the footprint were measured relative to the apex of the deep cartilage at the posteromedial aspect of the lateral femoral condyle, and the surface area of the ACL femoral footprint was approximated from multiplanar reformatted images. After 1 month, the measurements were repeated. Intraclass correlation coefficients (ICCs) were calculated to assess for intra- and interobserver reliability. Bland-Altman plots were produced to screen for potential systematic bias in measurement and to calculate limits of agreement.Results:The ICCs for intraobserver reliability of the ACL femoral distal and anterior footprint coordinates were 0.75 and 0.78, respectively, for observer A. For observer B, they were 0.75 and 0.74, respectively. The ICCs for interobserver reliability were 0.75 and 0.85 for the distal and anterior coordinates, respectively. Bland-Altman plots demonstrated no significant systematic bias. For surface area measurements, the intraobserver ICCs were 0.37 and 0.62 for observers A and B, respectively. The interobserver reliability was 0.60. Observer B consistently measured the footprints as slightly larger versus observer A (1.19 ± 0.27 vs 1 ± 0.22 cm2, respectively; P < .001).Conclusion:Locating the center of the anatomic footprint of the ACL with 3D MRI showed substantial intra- and interobserver agreement. Interobserver agreement for the femoral footprint surface area was fair to moderate.

Anterolateral ligament reconstruction in addition to primary double-bundle anterior cruciate ligament reconstruction for grade 3 pivot shift improves residual knee instability during surgery

PurposeHigh-grade pivot shift in the anterior cruciate ligament (ACL) injured knee is a risk factor for postoperative residual pivot shift. Procedures in addition to ACL reconstruction such as anterolateral ligament (ALL) reconstruction have been performed for patients with a high-risk of residual pivot shift. The aim of this study was to investigate the effect of the addition of ALL reconstruction to primary double-bundle ACL reconstruction in patients with preoperative high-grade pivot shift to improve stability as evaluated by quantitative measurement.MethodsPatients with ACL injuries who showed preoperative grade 3 subjective pivot shift and who underwent primary double-bundle ACL reconstruction combined with ALL reconstructions were retrospectively enrolled. Anterior tibial translation (ATT) in the Lachman test, and acceleration and external rotational angular velocity (ERAV) in the pivot shift were measured as quantitative values. Quantitative values before surgical intervention for ACL-injured knees (ACLD) and uninjured contralateral knees (intact), after temporary fixation of the isolated ACL grafts (ACLR), and subsequently after temporary fixation of both ACL and ALL grafts (ACLR + ALLR) were measured with the patient under general anaesthesia.ResultsIn total, 18 patients were included. The ATT was lower in ACLR and ACLR + ALLR than in intact (P = .008 and .005), while there was no significant difference between ACLR and ACLR + ALLR (P > .05). The acceleration of ACLR + ALLR was lower than that for ACLR (P = .008), while there was no significant difference between intact and ACLR or ACLR + ALLR (P > .05). The ERAV of ACLR was higher than that of intact (P < .001), while that of ACLR + ALLR was lower than that of ACLR (P < 0.001), and there was no significant difference in ERAV between intact and ACLR + ALLR (P > 0.05).ConclusionAccording to quantitative assessment of the pivot shift, the addition of ALL reconstruction to primary double-bundle ACL reconstruction improved residual knee instability and restored knee stability during surgery. Combination of ALL reconstruction with primary double-bundle ACL reconstruction was effective for patients with ACL injuries exhibiting a preoperative grade 3 subjective pivot shift.Level of evidenceIV

Change in Posterior Tibial Slope in Skeletally Immature Patients With Anterior Cruciate Ligament Injury: A Case Series With a Mean 9 Years’ Follow-up

Background: Increased lateral posterior tibial slope (LPTS) is associated with increased rates of anterior cruciate ligament (ACL) injury and failure of ACL reconstruction. It is unknown if ACL deficiency influences the developing proximal tibial physis and slope in skeletally immature patients through anterior tibial subluxation and abnormal force transmission. Purpose: To assess the natural history of LPTS in skeletally immature patients with an ACL-injured knee. Study Design: Case series; Level of evidence, 4. Methods: A total of 38 participants from a previous study on nonoperative management of ACL injury in skeletally immature patients were included. During the initial study, bilateral knee magnetic resonance imaging (MRI) was performed within 1 year of enrollment and again at final follow-up. All patients were younger than 13 years at the time of enrollment, and final follow-up occurred a mean 10 years after the injury. MRI scans were retrospectively reviewed by 2 reviewers to determine bilateral LPTS for each patient and each time point. Linear mixed models were used to assess LPTS differences between knees, change over time, and association with operational status. Subgroup analyses were performed for patients who remained nonoperated throughout the study. Results: A total of 22 patients had ACL reconstruction before final follow-up and 16 remained nonoperated. In the entire study population, the mean LPTS was higher in the injured knee than in the contralateral knee at final follow-up by 2.0° (P < .001; 95% CI, 1.3°–2.6°). The mean LPTS increased significantly in the injured knee by 0.9° (P = .042; 95% CI, 0.03°–1.7°), while the mean LPTS decreased in the contralateral knee by 0.4° (P = .363; 95% CI, –0.8° to 0.4°). A significant difference in LPTS was also observed in the nonoperated subgroup. No significant association was observed between LPTS and operational status. Conclusion: Lateral posterior tibial slope increased more in the ACL-injured knee than in the contralateral uninjured knee in a group of skeletally immature patients. Lateral posterior tibial slope at baseline was not associated with the need for surgical reconstruction over the study period.

Tibiofemoral bony morphology features associated with ACL injury and sex utilizing three-dimensional statistical shape modeling.

Statistical shape modeling was employed to assess three-dimensional (3D) bony morphology between distal femurs and proximal tibiae of anterior cruciate ligament (ACL) injured knees, the contralateral uninjured knees of ACL injured subjects, and knees with no history of injury. Surface models were created by segmenting bone from bilateral computed-tomography scans of 20 subjects of their ACL injured knees and non-injured contralateral knees, and 20 knees of control subjects with no history of a knee injury. Correspondence particles were placed on each surface, and a principal component analysis determined modes of variation in the positions of the correspondence particles describing anatomical variation. ANOVAs assessed the statistical differences of 3D bony morphological features with main effects of injury state and sex. ACL injured knees were determined to have a more lateral femoral mechanical axis and a greater angle between the long axis and condylar axis of the femur. A smaller anterior-posterior dimension of the lateral tibial plateau was also associated with ACL injured knees. Results of this study demonstrate that there are more bony morphological features predisposing individuals for ACL injury than previously established. These bony morphological parameters may cause greater internal and valgus torques increasing stresses in the ACL. No differences were determined between the ACL injured knees and their uninjured contralateral knees demonstrating that knees of ACL injured individuals are at similar risk for injury. Further understanding of the effect of bony morphology on the risk for ACL injury could improve individualized ACL injury treatment and prevention.

Do Bone-Patellar Tendon-Bone ACL-Reconstructed Knees Have More Signs of Patellofemoral Posttraumatic Osteoarthritis Than Their Uninjured Contralateral Knees at 2 Years?

Background:The prevalence of patellofemoral joint (PFJ) osteoarthritis ranges from 8% to 47% at 7 to 10 years after anterior cruciate ligament reconstruction (ACLR) using bone–patellar tendon–bone (BTB) autograft. In performing BTB ACLR, some hypothesize that either trauma caused by harvest of the BTB autograft or altered biomechanics contributes to PFJ posttraumatic osteoarthritis.Purpose/Hypothesis:To determine whether knees with ACLR using a BTB autograft show early signs of posttraumatic osteoarthritis as compared with the contralateral uninjured knee 2 years after ACLR. We hypothesized that a BTB autograft will not increase the prevalence of PFJ osteoarthritis.Study Design:Cohort study; Level of evidence, 3.Methods:Bilateral knee 3-T magnetic resonance imaging (MRI) scans were collected in 57 patients (mean age, 20.3 years; 28 men) from a single site at a minimum of 2 years after ACLR. Structural MRI assessment of the knees was performed using the MRI Osteoarthritis Knee Score semiquantitative scoring system by a board-certified musculoskeletal radiologist. The presence of cartilage defects in the patellofemoral compartment was compared between the reconstructed and contralateral uninjured knees using logistic regression analyses.Results:There were no significant differences in the prevalence of cartilage defects (full thickness or any thickness) in the PFJ between the BTB ACLR knees and the contralateral control knees: 38.6% of BTB ACLR knees had PFJ cartilage defects versus 31.6% of contralateral control knees (P > .391). The 95% CI for the difference between these groups was –9.0% to 23.0%.Conclusion:When comparing BTB ACLR knees with the uninjured contralateral knees in the study patients, we failed to observe statistically significant differences in the prevalence of PFJ cartilage lesions of full thickness or any thickness. These results should be used in shared decision-making with athletes when choosing the appropriate autograft during reconstruction. Our wide 95% CIs secondary to a smaller sample size demonstrate a need for larger studies in this area to more accurately describe the difference between the operative and contralateral knees.

Kinetic and Kinematic analysis of ACL reconstruction in association with lateral-extrarticular tenodesis of the knee in revision surgery: a pilot study.

Background.Anterior cruciate ligament reconstructions are a very frequent surgery. The key role of the anterolateral ligament in the knee rotational stability has been undelighted in recent years. Extra-articular tenodesis in association with ACL reconstructions, serves to eliminate anterolateral rotatory instability. The aim of our study is to compare treated knees with the contralateral uninjured knee in those cases whom been treated with ACL arthroscopic reconstruction and lateral extra-articular tenodesis in revision surgery, and evaluate clinical results with kinematic and kinetic examinations methods.Materials and methods.Sixteen patients (10 males and 6 females) with ages from 21 to 37 had been treated at the Orthopaedic Clinic of Udine for failure of previous ACL reconstruction. In all patients was performed ACL arthroscopic reconstruction with the association of a lateral extra-articular tenodesis (Coker-Arnold). We have decided to asses the patients at one year after surgery with GNRB arthrometer and Bioval inertial sensor system.Results.All patients treated with arthroscopic ACL reconstruction and lateral extra-articular tenodesis have regained pre-injury sagittal knee stability and gait dynamics.Conclusions.Clinical and instrumental evaluation showed how a combination of procedures can restore the kinematic and stability of a joint, even if the procedures performed are not anatomical. These are only preliminary data. (www.actabiomedica.it)

Proprioception After Multiligament Knee Injury: Does Ligament Repair Lead to Better Proprioceptive Acuity Than Ligament Reconstruction?

IntroductionMultiligament knee injuries are uncommon but serious injuries. There is ongoing debate on the optimal treatment of these injuries. We designed a study to establish the effects of repair or reconstruction on proprioceptive outcomes following multiligament injury to the knee.Materials and MethodsA total of 34 patients were analysed by independent researchers who had no conflict of interest in the cases (23 in the repair group and 11 in the reconstruction group). Proprioception of the knee was measured using a previously validated tool to assess the reproduction of passive positioning. Functional outcome was measured using the Lysholm score. Sub-group analysis was performed. The mean time from injury to review was 83 months (range: 25-193 months).ResultsThere were no significant differences in proprioceptive acuity between the injured (5.9±4.2°; range: 1.0-18.3°) and uninjured contralateral (control) knees (5.2±3.8°; range: 1.0-15.0°; p=0.35). Similarly, there was no significant difference in proprioceptive acuity identified between the injured knees that underwent repair (6.0±4.3°; range: 1.0-18.3°) or reconstruction (5.0±3.6°; range: 1.3-14°; p=0.53).Overall knee outcomes were good; the mean Lysholm score at final follow-up was 75.5±16.8 (range: 36-100). No significant differences were identified in any of the sub-groups.ConclusionsWe were unable to identify any differences in knee proprioceptive acuity between injured knees and controls nor between the types of surgical treatment, demonstrating equivocal recovery for both methods of treatment.

Risk of overconstraining femorotibial rotation after anatomical ACL reconstruction using bone patella tendon bone autograft.

Numerous studies have focused on the anteroposterior stability after anterior cruciate ligament (ACL) reconstruction, with less emphasis on rotational stability. It has been hypothesized that bone patella tendon bone (BTB) autograft for ACL reconstruction restores knee rotation closely to normal due to its comparable fiber orientation to the native ACL. Twenty patients with unilateral ACL rupture and an uninjured contralateral knee were included in this study. The ACL was reconstructed using the medial third of the patellar tendon. Tunnel placement was controlled by fluoroscopy. Implant-free press-fit graft fixation was used on both femoral and tibial side. Bone blocks were carefully placed to restore fiber orientation of both the anteromedial and posterolateral bundle, similar to the native ACL. Rotatory laxity of both knees was measured at 0° and 25° of flexion pre- and post-surgery, using an active opto-electronical motion-analysis system (LUKOTRONIC AS 100®). All measurements were performed under general anesthesia during surgery. Knee rotation was reduced significantly in both 0°and 25° of flexion following ACL reconstruction (p < 0.001). The side to side difference (SSD) of the rotatory laxity in extension was greater in the ACL-deficient knee (14.9° ± 8.9°), but decreased significantly after ACL reconstruction (- 5.9° ± 7.7°, minus value means less than in the uninjured knee). There was a similar finding at 25° of knee flexion where greater rotation of the ACL-deficient knee (5.7° ± 10.3°) prior to surgery changed to lower degree of rotation after surgery (- 11.3° ± 8.4°) in comparison to the uninjured knee. ACL reconstruction with a BTB graft in anatomical position using press-fit implant-free fixation is able to restore rotatory knee stability close to the intact contralateral knee. Despite the fact that the BTB graft offers fiber orientation close to the natural ACL, the surgeon should be aware of the potential risk of over-constraining the knee in terms of rotation. II.