Contralateral Normal Knee Research Articles

Femoropatellar alterations in knees with chronic anterior cruciate ligament injuries: a radiographic analysis

Background: The objective of this study was to correlate the occurrence of patellofemoral malalignment in a chronic anterior cruciate ligament (ACL) deficient knee using common radiological parameters. Methods: A case-control study was conducted on 35 adult patients with previously diagnosed unilateral chronic ACL injury. The injured knee was considered as the case, while the contralateral normal knee served as the control. Radiological parameters including the Caton-Deschamps patellar height index, Merchant patellar congruence angle, and Laurin lateral patellar tilt angle were measured on X-rays obtained from both normal and ACL injured knees. A comparative analysis was performed between the two groups. Results: The Caton-Deschamps patellar height index had a mean value of 0.95±0.05 in the ACL-deficient knee. The Merchant patellar congruence angle showed mean values of 12.66±0.84 degrees in the ACL injured knee, while the Laurin lateral patellar tilt angle was 8.06±1.41 degrees in knees with ACL failure. These results indicate lower patellar height, greater lateral displacement of the patella, and increased lateral patellar tilt in knees with chronic ACL tears, thereby affecting the patellofemoral joint. Conclusions: Chronic ACL tears are associated with patellofemoral malalignment, characterized by decreased patellar height, increased lateral displacement of the patella, and greater lateral patellar tilt, thus impacting the patellofemoral joint.

Reference standards for stress radiography measurements in knee ligament injury and instability: a systematic review

AbstractPurposeStress radiographs are an easily accessible, cost‐effective tool in the evaluation of acute and chronic ligament knee injuries. Stress radiographs provide an objective, quantifiable, and functional assessment of the injured ligament and can be a useful adjunct when planning surgical management and to objectively assess postoperative outcomes. This study aimed to review the literature reporting on stress radiographic techniques in evaluating knee ligament injury and instability and propose thresholds for interpreting stress radiography techniques.MethodsThe following three databases, OVID MEDLINE, the EMBASE library, and the Cochrane Controlled Trials Register, were systematically searched on January 23, 2023, for studies published from January 1970 to January 2023. The search extended to the reference lists of all relevant studies and orthopedic journals. Included studies were those that described a stress technique for the diagnosis of knee ligament injury; studies that reported a description or comparison of the accuracy and/or reliability of one or several stress radiography techniques, or studies that reported a comparison with alternative diagnostic modalities.ResultsSixteen stress radiography techniques were reported for assessing the ACL with stress applied in the anterior plane, 10 techniques for assessing the PCL with stress applied in the posterior plane, 3 techniques for valgus stress, and 4 techniques for varus stress. The Telos device was the most commonly used stress device in the ACL and PCL studies. There was no consensus on the accuracy and reliability of stress radiography techniques for the diagnosis of any knee ligament injury. Stress radiography techniques were compared with alternative diagnostic techniques including instrumented arthrometry, MRI, and physical examination in 18 studies, with variability in the advantages and disadvantages of stress radiography techniques and alternatives. Analysis of results pooled from different studies demonstrated average delta gapping in knees with a completely injured ligament compared to the normal contralateral knee as per the following: for the ACL 4.9 ± 1.4 mm; PCL 8.1 ± 2.5 mm; MCL 2.3 ± 0.05 mm; and the FCL 3.4 ± 0.2 mm.ConclusionDespite heterogeneity in the available literature with regard to stress examination techniques and device utilization, the data support that stress radiography techniques were accurate and reliable when compared to numerous alternatives in the diagnosis of acute and chronic knee ligament injuries. The present study also provides average increased ipsilateral compartment gapping/translation for specific knee ligament injuries based on the best available data. These values provide a reference standard for the interpretation of stress radiography techniques, help to guide surgical decision‐making, and provide benchmark values for future investigations.Level of evidenceIII.

Patients With More Than 6.5° of Knee Hyperextension are 14.6 Times More Likely to Have Anterior Cruciate Ligament Hamstring Graft Rupture and Worse Knee Stability and Functional Outcomes

To create a cut-off point for hyperextension that best discriminates retear and to verify whether this cut-off point can predict retear regardless of other characteristics after primary anterior cruciate ligament (ACL) reconstruction with hamstrings autograft. A cohort of patients submitted to primary isolated ACL reconstruction with hamstrings autografts was retrospectively evaluated. Patients were stratified according to the degree of passive knee hyperextension measured in the normal contralateral knee. The following data were collected: patient age and sex, time from injury to surgery, knee hyperextension, KT-1000 and pivot-shift, associated meniscus injury, intra-articular graft size, follow-up time, graft failure, and postoperative Lysholm and subjective International Knee Documentation Committee scores. Data from 457 patients were evaluated. Median age was 31 years. Thirty-two (7.0%) presented with retear. There was a significant difference in hyperextension between patients with and without retear (P < .001), with the cut-off point established by the receiver operating characteristic curve from 6.5°. Patients with greater hyperextension had a statistically greater frequency of women, longer injury time, greater intra-articular graft diameter, greater postoperative KT-1000, and greater frequency of retear, whereas the subjective International Knee Documentation Committee and Lysholm scores were statistically lower in patients with greater hyperextension. Only hyperextension showed a statistically significant association with re-rupture (P < .001). The odds of retear in patients with hyperextension greater than 6.5 was 14.65 times the odds of patients with hyperextension less than 6.5. Patients with more than 6.5° of hyperextension are 14.6 times more likely to have a graft rupture than patients with lower hyperextension when submitted to ACL reconstruction with hamstring tendons. Also, they present worse knee stability by the KT-1000 test and worse functional outcomes. Therefore, patients with this degree of hyperextension should not have isolated reconstruction with hamstrings as their first choice. Level III, retrospective comparative prognostic trial.

Kneeling Stress Radiography: A Forgotten Yet Dependable Tool for Postero-lateral Knee Instability.

Diagnosing postero-lateral knee instability is a challenge from both clinical and radiologic perspective and can lead to significant morbidity if left untreated. Delayed diagnosis leads to a more demanding surgery and prolonged rehabilitation for the patient. Kneeling stress radiograph is a lost art but remains invaluable in the assessment of postero-lateral knee instability. This prospective observational study is aimed at re-exploring the undeniable utility of this forgotten tool in early diagnosis of posterolateral knee instability and identifying the mean posterior tibial translation distance (PTTD) and also assessing side to side difference (SSD) between the injured and the contralateral normal knee. Total 27 patients were included in the study, with males being 4.4 times more commonly injured as compared to females. The most common mode of injury was motor vehicle accident (MVA). Out of 27 patients, 11 had isolated PCL (posterior cruciate ligament) injury while the rest had PLC (posterolateral corner) involvement. The mean SSD of PTTD was 8.79mm in patient with isolated PCL. This was increased by 1.65 times (14.52mm) in patients with co-existing PLC involvement. Stress radiography is an indelible tool and serves as an adjunct to MRI imaging. It is not a substitute for clinical assessment but assists in early diagnosis and management, facilitating surgical planning and furnishing objective evidence of PCL/PLC functionality which is not possible with any other imaging modality.

Immune cell profiles in synovial fluid after anterior cruciate ligament and meniscus injuries

BackgroundAnterior cruciate ligament (ACL) and meniscus tears are common knee injuries. Despite the high rate of post-traumatic osteoarthritis (PTOA) following these injuries, the contributing factors remain unclear. In this study, we characterized the immune cell profiles of normal and injured joints at the time of ACL and meniscal surgeries.MethodsTwenty-nine patients (14 meniscus-injured and 15 ACL-injured) undergoing ACL and/or meniscus surgery but with a normal contralateral knee were recruited. During surgery, synovial fluid was aspirated from both normal and injured knees. Synovial fluid cells were pelleted, washed, and stained with an antibody cocktail consisting of fluorescent antibodies for cell surface proteins. Analysis of immune cells in the synovial fluid was performed by polychromatic flow cytometry. A broad spectrum immune cell panel was used in the first 10 subjects. Based on these results, a T cell-specific panel was used in the subsequent 19 subjects.ResultsUsing the broad spectrum immune cell panel, we detected significantly more total viable cells and CD3 T cells in the injured compared to the paired normal knees. In addition, there were significantly more injured knees with T cells above a 500-cell threshold. Within the injured knees, CD4 and CD8 T cells were able to be differentiated into subsets. The frequency of total CD4 T cells was significantly different among injury types, but no statistical differences were detected among CD4 and CD8 T cell subsets by injury type.ConclusionsOur findings provide foundational data showing that ACL and meniscus injuries induce an immune cell-rich microenvironment that consists primarily of T cells with multiple T helper phenotypes. Future studies investigating the relationship between immune cells and joint degeneration may provide an enhanced understanding of the pathophysiology of PTOA following joint injury.

FUNCTIONAL OUTCOME OF ARTHROSCOPE ASSISTED RECONSTRUCTION OF ANTERIOR CRUCIATE LIGAMENT USING BONE-PATELLAR TENDON-BONE GRAFT

Objective: To evaluate arthroscopic assisted Anterior Cruciate Ligament (ACL) reconstruction using Bone-Patellar Tendon-Bone (BPTB) graft using anteromedial approach to drill the femoral tunnel followed by accelerated ACL rehabilitation protocol in terms of Lysholm score. Study Design: Prospective comparative study. Place And Duration Of Study: The study was conducted in Department of Orthopaedics, Patna Medical College and Hospital, Patna, Bihar from May 2018 to April 2019. Methodology: This study was an analysis of prospectively collected data of patients who had undergone Anterior Cruciate Ligament reconstruction. All patients below the age of 35 years presenting with Anterior Cruciate Ligament Grade 3 tear were assessed objectively and subjectively using Lysholm score pre and post operatively. Manual laxity of knee was assessed with anterior drawer and Lachman test; and being compared with normal contralateral knee. Rotational instability was assessed by pivot shift test. Results: Nineteen patients, all males, were included in this study with the mean age of 26.7 ± 4.68 years. All patients underwent arthroscopic assisted Anterior Cruciate Ligament reconstruction with uneventful recovery. Every patient had his pre and post-operative Lysholm scoring done. Mean pre-operative Lysholm score was 53.89± 3.81. Patients were followed up at 5 months and at 9 months and their mean Lysholm scores were 84.74 ± 6.31 and 92.47 ± 3.04 respectively with the p-value of &lt;0.001. Only 2 patients had residual Grade I Lachman laxity and none of the patients had any rotational instability. Conclusion: Arthroscopic assisted Anterior Cruciate Ligament reconstruction using Bone-Patellar Tendon-Bone graft followed by accelerated Anterior Cruciate Ligament rehabilitation protocol led to signicant improvement of Lysholm score.

The arithmetic HKA (aHKA) predicts the constitutional alignment of the arthritic knee compared to the normal contralateral knee: a matched-pairs radiographic study.

AimsAn algorithm to determine the constitutional alignment of the lower limb once arthritic deformity has occurred would be of value when undertaking kinematically aligned total knee arthroplasty (TKA). The purpose of this study was to determine if the arithmetic hip-knee-ankle angle (aHKA) algorithm could estimate the constitutional alignment of the lower limb following development of significant arthritis.MethodsA matched-pairs radiological study was undertaken comparing the aHKA of an osteoarthritic knee (aHKA-OA) with the mechanical HKA of the contralateral normal knee (mHKA-N). Patients with Grade 3 or 4 Kellgren-Lawrence tibiofemoral osteoarthritis in an arthritic knee undergoing TKA and Grade 0 or 1 osteoarthritis in the contralateral normal knee were included. The aHKA algorithm subtracts the lateral distal femoral angle (LDFA) from the medial proximal tibial angle (MPTA) measured on standing long leg radiographs. The primary outcome was the mean of the paired differences in the aHKA-OA and mHKA-N. Secondary outcomes included comparison of sex-based differences and capacity of the aHKA to determine the constitutional alignment based on degree of deformity.ResultsA total of 51 radiographs met the inclusion criteria. There was no significant difference between aHKA-OA and mHKA-N, with a mean angular difference of −0.4° (95% SE −0.8° to 0.1°; p = 0.16). There was no significant sex-based difference when comparing aHKA-OA and mHKA-N (mean difference 0.8°; p = 0.11). Knees with deformities of more than 8° had a greater mean difference between aHKA-OA and mHKA-N (1.3°) than those with lesser deformities (-0.1°; p = 0.009).ConclusionThis study supports the arithmetic HKA algorithm for prediction of the constitutional alignment once arthritis has developed. The algorithm has similar accuracy between sexes and greater accuracy with lesser degrees of deformity.Cite this article: Bone Joint Open 2020;1-7:339–345.

Do BTB ACLR Knees have more MRI signs of PTOA than their Contralateral Normal Knee at 2 Years?

Objectives:The prevalence of patellofemoral joint (PFJ) osteoarthritis (OA) ranges from 8-47% 7-10 years after anterior cruciate ligament reconstructions (ACLR) using bone-patellar tendon-bone (BTB) autograft. In performing BTB ACLR, some hypothesize that either trauma caused by harvest of the patellar bone autograft or altered biomechanics lead to PFJ post traumatic osteoarthritis (PTOA). Our objective was to evaluate by 3T MRI whether the ACLR knees had more signs of early PTOA compared to the contralateral knee within the MOON nested cohort. We hypothesize that a BTB autograft harvested using a minimally traumatic technique will not increase the risk of PFJ OA.Methods:MRIs of operative and contralateral uninjured knees were collected in 60 patients (28 males, mean age 21 years) from a single site in the Multicenter Orthopaedic Outcomes Network (MOON) nested cohort at minimum 2 years post BTB ACLR. Harvesting the patellar block for the BTB autograft was performed using an oscillating saw with a narrow blade, being careful not to extend the cut into the posterior cortex of the patella, and with gentle elevation of the bone block with an osteotome. MRI was performed at 3T (Philips, Achieva) and the imaging protocol included intermediate-weighted sagittal turbo spin-echo (TSE) imaging, axial and coronal fat-saturated TSE imaging, and 3D coronal gradient echo imaging. Structural MRI assessment of the knees was performed using the MRI Osteoarthritis Knee Score (MOAKS) semi-quantitative scoring system by a board-certified musculoskeletal radiologist. The prevalence of cartilage defects in each knee compartment (medial, lateral, patellofemoral), meniscal tears (medial, lateral; yes/no), bone marrow edema-like lesions (BMEL; medial, lateral, patellofemoral; yes/no), effusion (yes/no) and Hoffa synovitis (yes/no) were compared between the reconstructed and contralateral uninjured knees. Hypothesis testing was performed for the PF joint using a logistic regression model where the dependent variable was presence/absence of cartilage loss and the independent variable was knee status (surgical or contralateral).Results:There were no significant differences in the prevalence of cartilage defects (any lesions or full thickness loss) in the PFJ between the surgical BTB ACLR knees and the uninjured non-operative contralateral control knees. 38.3% of BTB ACLR knees had PFJ cartilage defects versus 31.7% of contralateral control knees with PFJ cartilage defects (p>0.05) (Table 1). The BTB ACLR knees had more cartilage defects in the medial and lateral tibiofemoral compartments, more meniscal tears, BMEL, effusion and Hoffa synovitis, than the contralateral knees. Figure 1 shows examples of PFJ cartilage defects on MRI for the reconstructed and contralateral uninjured knees. At 2 years follow-up, KOOS symptoms, sports, pain, and activities of daily living scores were maintained at a high level ranging from 88-98.Conclusion:Although prior studies suggest BTB ACLR increases the risk of PFJ OA, the current study shows no difference in MRI signs of early PTOA in the PFJ. Cartilage defects comparing reconstructed vs. contralateral uninjured knees 2 years after surgery based on MRI were not different. These results should be used in shared decision making with athletes in choosing the appropriate autograft during reconstruction. Future studies will investigate the influence of cartilage defects found in the medial and lateral compartments further.

The arithmetic HKA (aHKA) predicts the constitutional alignment of the arthritic knee compared to the normal contralateral knee

Aims An algorithm to determine the constitutional alignment of the lower limb once arthritic deformity has occurred would be of value when undertaking kinematically aligned total knee arthroplasty (TKA). The purpose of this study was to determine if the arithmetic hip-knee-ankle angle (aHKA) algorithm could estimate the constitutional alignment of the lower limb following development of significant arthritis. Methods A matched-pairs radiological study was undertaken comparing the aHKA of an osteoarthritic knee (aHKA-OA) with the mechanical HKA of the contralateral normal knee (mHKA-N). Patients with Grade 3 or 4 Kellgren-Lawrence tibiofemoral osteoarthritis in an arthritic knee undergoing TKA and Grade 0 or 1 osteoarthritis in the contralateral normal knee were included. The aHKA algorithm subtracts the lateral distal femoral angle (LDFA) from the medial proximal tibial angle (MPTA) measured on standing long leg radiographs. The primary outcome was the mean of the paired differences in the aHKA-OA and mHKA-N. Secondary outcomes included comparison of sex-based differences and capacity of the aHKA to determine the constitutional alignment based on degree of deformity. Results A total of 51 radiographs met the inclusion criteria. There was no significant difference between aHKA-OA and mHKA-N, with a mean angular difference of −0.4° (95% SE −0.8° to 0.1°; p = 0.16). There was no significant sex-based difference when comparing aHKA-OA and mHKA-N (mean difference 0.8°; p = 0.11). Knees with deformities of more than 8° had a greater mean difference between aHKA-OA and mHKA-N (1.3°) than those with lesser deformities (-0.1°; p = 0.009). Conclusion This study supports the arithmetic HKA algorithm for prediction of the constitutional alignment once arthritis has developed. The algorithm has similar accuracy between sexes and greater accuracy with lesser degrees of deformity. Cite this article: Bone Joint Open 2020;1-7:339–345.

Moderately Increased Post-Operative Anterior Knee Laxity does not Predict Decreases in Patient-Reported Outcome Scores or Subsequent Knee Surgery between 2 and 6 Years after ACL reconstruction

Objectives:A primary goal of anterior cruciate ligament reconstruction is to reduce pathologically increased anterior and rotational laxity of the knee. The impact of residual anterior laxity on patient-reported outcomes and the risk of subsequent ipsilateral knee surgery has not been clearly elucidated. The goal of this study is to determine the influence of residual anterior knee laxity on changes in patient-reported outcomes from 2 to 6 years following ACL reconstruction and risk of subsequent ipsilateral knee surgery during that period.Methods:From a prospective multi-center cohort of patients, 429 patients under age 35 years injured in sports with no history of concomitant ligament surgery, revision ACL surgery, or surgery of the contralateral knee were identified at a minimum 2 years following primary ACL reconstruction. These patients underwent a KT-1000 assessment of anterior knee laxity examination relative to the contralateral normal knee by an independent examiner and completed patient-reported outcome assessments with KOOS and IKDC scores. Patients were followed until the 6-year mark following ACL reconstruction and any ipsilateral knee surgeries performed during this period were noted. Patients completed the same patient-reported outcome assessments at 6 years post-operative. Subsequent surgery risk was calculated and compared between those patients with side-to-side KT-1000 differences between -1 and 2 mm and those with a side-to-side KT-1000 differences between 2 and 6mm. Multiple linear regression models were built to determine the relationship between KT-1000 and 2 to 6 year change in patient-reported outcome score while controlling for age, sex, BMI, smoking status, meniscus and cartilage status, and graft type.Results:Thee hundred seventy-seven patients (87.9%) were available for follow-up at the six year mark post-operative. There were 36 patients with a side to side KT-1000 difference less than -1 mm (tighter than contralateral) that were excluded from the analysis. Side-to-side KT-1000 difference was between -1 and 2 mm (IKDC A) in 153 patients, between 2 and 6 mm (IKDC B) in 162 patients, and greater than 6 mm in 26 patients. Subsequent knee surgery was performed significantly more patients in the IKDC A group (23 of 153 patients, 15%) than in the IKDC B group (13 of 162 patients, 8%) (p = 0.05). Increased side-to-side KT-1000 differences at 2-year post-operative were correlated with decreases in subjective IKDC score (β = -0.67, p = 0.038) and KOOS-sport subscale (β = -0.90, p = 0.029) but not with other KOOS subscales. A 5mm increase in anterior laxity at 2 years would predict a 3.4 point decrease in IKDC subjective score and a 4.5 point decrease in the KOOS sport subscale at 6 years post-operative.Conclusion:Three presence of 2 to 6 mm of residual side-to-side KT-1000 difference is not associated with an increased risk of subsequent ipsilateral knee surgery or clinically relevant decrease in patient-reported outcome score up to 6 years following ACL reconstruction.

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

Background: Physicians’ and patients’ decision-making process between bone–patellar tendon–bone (BTB) and hamstring tendon autografts for anterior cruciate ligament (ACL) reconstruction (ACLR) may be influenced by a variety of factors in the young, active athlete. Purpose: To determine the incidence of both ACL graft revisions and contralateral ACL tears resulting in subsequent ACLR in a cohort of high school– and college-aged athletes who initially underwent primary ACLR with either a BTB or a hamstring autograft. Study Design: Cohort study; Level of evidence, 2. Methods: Study inclusion criteria were patients aged 14 to 22 years who were injured in sports, had a contralateral normal knee, and were scheduled to undergo unilateral primary ACLR with either a BTB or a hamstring autograft. All patients were prospectively followed for 6 years to determine whether any subsequent ACLR was performed in either knee after their initial ACLR. Multivariable regression modeling controlled for age, sex, ethnicity/race, body mass index, sport and competition level, baseline activity level, knee laxity, and graft type. The 6-year outcomes were the incidence of subsequent ACLR in either knee. Results: A total of 839 patients were eligible, of which 770 (92%) had 6-year follow-up for the primary outcome measure of the incidence of subsequent ACLR. The median age was 17 years, with 48% female, and the distribution of BTB and hamstring grafts was 492 (64%) and 278 (36%), respectively. The incidence of subsequent ACLR at 6 years was 9.2% in the ipsilateral knee, 11.2% in the contralateral normal knee, and 19.7% for either knee. High-grade preoperative knee laxity (odds ratio [OR], 2.4 [95% confidence interval [CI], 1.4-3.9]; P = .001), autograft type (OR, 2.1 [95% CI, 1.3-3.5]; P = .004), and age (OR, 0.8 [95% CI, 0.7-1.0]; P = .009) were the 3 most influential predictors of ACL graft revision in the ipsilateral knee. The odds of ACL graft revision were 2.1 times higher for patients receiving a hamstring autograft than patients receiving a BTB autograft (95% CI, 1.3-3.5; P = .004). No significant differences were found between autograft choices when looking at the incidence of subsequent ACLR in the contralateral knee. Conclusion: There was a high incidence of both ACL graft revisions and contralateral normal ACL tears resulting in subsequent ACLR in this young athletic cohort. The incidence of ACL graft revision at 6 years after index surgery was 2.1 times higher with a hamstring autograft compared with a BTB autograft.

Role of Ultrasound in Assessment of Menisco-Ligamentous Injuries of Knee Joint in Comparison with Magnetic Resonance Imaging

AbstractBackground: While considering the Magnetic Resonance Imaging (MRI) as 'gold standard' for detection of knee liga-mentous and meniscal injuries, we are determining the use-fulness of Ultrasound (US) in various knee injuries and correlate the findings of US with the findings of MRI.Aim of Study: to assess the diagnostic utility of ultrasound in patient with suspected ligaments or menisci injuries of knee joint keeping MRI as the Gold standard.Material and Methods: This prospective study included 30 patients who were referred to the Radiology Department with clinically suspected meniscal/ligamentous injury of the knee. After detailed clinical examination, US examination of the involved knee was performed together with an examination of the contralateral normal knee, followed by MRI of the symptomatic knee in all 30 patients. The MRI findings were considered as final. Sensitivity and specificity for ultrasound in knee injuries was calculated with correlation with MRI.Results: In the present study, the majority of patients were in age group 18-57 years, 70% were males and 30% were females (of a total of 30 patients). A total of 30 patients were diagnosed as having ligamentous/meniscal tears on US and MRI. In the diagnosis of meniscal/ligamentous tears, the strength of agreement between US and MRI was good.Conclusion: US of the knee shows promising results in the diagnosis of meniscal/ligamentous tears. A wide availability, cost effectiveness and better tolerability of US make it a modality of first choice for evaluating knee injuries.

Evaluating the Accuracy of Tibial Tunnel Placement After Anatomic Single-Bundle Anterior Cruciate Ligament Reconstruction

Background: Anatomic anterior cruciate ligament (ACL) reconstruction improves knee kinematics and joint stability in symptomatic patients who have ACL deficiency. Despite a concerted effort to place the graft within the ACL’s native attachment sites, the accuracy of tunnel placement using contemporary techniques is not well established. Purpose: To use 3-dimensional magnetic resonance imaging (3D MRI) to prospectively evaluate the accuracy of tibial tunnel placement after anatomic ACL reconstruction. Study Design: Case series; Level of evidence, 4. Methods: Forty patients with symptomatic, ACL-deficient knees were prospectively enrolled in the study and underwent 3D MRI of both their injured and uninjured knees before and after surgery through use of a validated imaging protocol. The root ligament of the anterior horn of the lateral meniscus was used as a radiographic reference, and the center of the reconstructed graft was compared with that of the contralateral normal knee. The tunnel angles and intra-articular graft angles were also measured, as was the percentage overlap between the native tibial footprint and tibial tunnel. Results: The reconstructed tibial footprint was placed at a mean ± SD of 2.14 ± 2.45 mm (P < .001) medial and 5.11 ± 3.57 mm (P < .001) posterior to the native ACL footprint. The mean distance between the center of the native and reconstructed ACL at the tibial attachment site was 6.24 mm. Of the 40 patients, 18 patients had a tibial tunnel that overlapped more than 50% of the native footprint, and 10 patients had maximal (100%) overlap. Further, 22 of the 40 patients had less than 50% overlap with the native footprint, and in 12 patients the footprint was missing completely. Conclusion: Despite the use of contemporary surgical techniques to perform anatomic ACL reconstruction, a significant positioning error in tibial tunnel placement remains.

Radiographically normal knees with contralateral joint space narrowing display greater change in cartilage transverse relaxation time than those with normal contralateral knees: a model of early OA? – data from the Osteoarthritis Initiative (OAI)

To develop a model of early osteoarthritis, by examining whether radiographically normal knees with contralateral joint space narrowing (JSN), but without contralateral trauma history, display greater longitudinal cartilage composition change (transverse relaxation time; T2) than subjects with bilaterally normal knees. 120 radiographically normal knees (Kellgren Lawrence grade [KLG] 0) from the Osteoarthritis Initiative were studied. 60 case knees displayed definite contralateral radiographic knee osteoarthritis (KLG≥2) whereas 60 reference subjects were bilaterally KLG0, and were matched 1:1 to cases based on age, sex, and BMI. All had multi-echo spin-echo MRI acquired at year (Y) 1 and 4 follow-up, with cartilage T2 being determined in superficial and deep cartilage layers across 16 femorotibial subregions. T2 across all regions was considered the primary analytic focus. Of 60 KLG0 case knees (30 female, age: 65.0±8.8y, BMI: 27.6±4.4kg/m2), 21/22/13/4 displayed contralateral JSN 0/1/2/3, respectively. The longitudinal increase in the deep layer cartilage T2 between Y1 and Y4 was significantly greater (P=0.03; Cohen's D 0.50) in the 39 KLG0 case knees with contralateral JSN (1.2ms; 95% confidence interval [CI] [0.4, 2.0]) than in matched KLG0 reference knees (0.1ms; 95% CI [-0.5, 0.7]). No significant differences were identified in superficial T2 change. T2 at Y1 was significantly greater in case than in reference knees, particularly in the superficial layer of the medial compartment. Radiographically normal knees with contralateral, non-traumatic JSN represent an applicable model of early osteoarthritis, with deep layer cartilage composition (T2) changing more rapidly than in bilaterally normal knees. CLINICALTRIALS. NCT00080171.

ACL Reconstruction In High School and College-aged Athletes: Does Autograft Choice Affect Recurrent ACL Revision Rates?

Objectives: Physicians’ and patients’ decision-making process between bone-patellar tendon-bone (BTB) versus hamstring autografts for ACL reconstruction (ACLR) may be influenced by a patient’s gender, laxity level, sport played, and/or competition level in the young, active athlete. The purpose of this study was to determine the incidence of subsequent ligament disruption for high school and college-aged athletes between autograft BTB versus hamstring grafts for ACLRs. Our hypothesis is there would be no recurrent ligament failure differences between autograft types at 6-year follow-up. Methods: Our inclusion criteria were patients aged 14-22 who were injured in sport (basketball, football, soccer, other), had a contralateral normal knee, and were due to have a unilateral primary ACLR with either a BTB or hamstring autograft. All patients were prospectively followed at two and six years and contacted by phone and/or email to determine whether any subsequent surgery had occurred to either knee since their initial ACLR. If so, operative reports were obtained, whenever possible, in order to document pathology and treatment. Multivariable regression modeling controlled for age, gender, ethnicity/race, body mass index, sport and competition level, activity level, knee laxity, and graft type. The six-year outcomes of interest were the incidence of subsequent ACL reconstruction to either knee. Results: Eight hundred thirty-nine (839) patients were eligible, of which 770 (92%) had 6-year follow-up for subsequent surgery outcomes. The median age was 17, with 48% females, and the distribution of BTB to hamstring was 492 (64%) and 278 (36%) respectively. Thirty-three percent (33%) of the cohort was classified as having “high grade” knee laxity preoperatively. The overall ACL revision rate was 9.2% in the ipsilateral knee, 11.2% in the contralateral normal ACL, and 19.7% had one or the other within 6 years of the index ACLR surgery. High-grade laxity (OR: 2.4; 95% CI: 1.4, 3.9; p=0.001), autograft type (OR: 2.1; 95% CI: 1.3, 3.5; p=0.004), and age (OR: 0.8; 95% CI: 0.7, 0.96; p=0.009) were the 3 most influential predictors of a recurrent ACL graft revision on the ipsilateral knee, respectively, whereas the sport of the index injury (OR: 0.3; 95% CI: 0.2, 0.7; p=0.002) was the most influential predictor of a subsequent primary ACL reconstruction on the contralateral knee. The odds of a recurrent ACL graft revision on the ipsilateral knee for patients receiving a hamstring autograft were 2.1 times the odds of a patient receiving a BTB autograft (95% CI: 1.3, 3.5). For low-risk patients (5% incidence of graft failure), a hamstring graft can increase the risk of recurrent ACL graft revision by 5 percentage points, from 5% to 10%. For high-risk patients (35% incidence of graft failure), a hamstring graft can increase the risk of recurrent ACL graft revision by 15 percentage points, from 35% to ˜ 50%. An individual prediction risk calculator for a subsequent ACL graft revision can be determined by the nomogram in Figure 1. Conclusion: There is a high rate of subsequent ACL tears in both the ipsilateral and contralateral knees in this young athletic cohort, with evidence suggesting that incidence of ACL graft revisions at 6 years following index surgery is significantly higher in hamstring autograft compared to BTB autograft. [Figure: see text]

Comparative study of existing knee prosthesis with anthropometry of Indian patients and other races, a computer tomography 3D reconstruction-based study

Background: Appropriate component sizing plays an important role in determining the functional outcome following total knee arthroplasty. Comparative studies of different populations have shown significant differences in the anthropometric parameters of knees in different race groups which negates the possibility of using a single sized implant system across different ethnic groups. This study evaluates the dimensions of femoral and tibial articular surfaces of Indian patients and compares the parameters with other ethnic groups and correlates the dimensions with five different commercially available knee systems.Material & Methods: Computerized tomography (CT) scans of contralateral normal knees of patients who underwent the scan for various ailments of the knee were retrieved retrospectively from the hospital database and 3D reconstruction of the images was done. Mediolateral dimensions (fML,tML), Anteroposterior dimensions (fAP, tAP) and aspect ratio (fML/fAP, tML/tAP) of the femur and tibia respectively were calculated and compared with the dimensions of different ethnic groups as well as the femoral and tibial components of five different knee prosthesis systems. ResultsThe average fML in the study group was less than that of Caucasian knees but was marginally larger than other ethnic groups. The fAP, tML and tAP was found to be smaller than all other ethnic groups but a larger femoral aspect ratio was reported than other ethnic groups. Among the implant systems, only NexGen LPS and Scorpio NRG implant femoral components closely matched the femoral dimensions in the study group whereas all implant systems showed significant mismatch with tibial component dimensions when compared to the study populations. ConclusionThis study concludes that the dimensions of Indian knees are different from other ethnic groups and the use of commercially available knee Implants designed based on measurements in Caucasian populations can lead to significant mismatch between implant and resected bone surfaces.

Does radiographic knee OA status impact age-related reduction of thigh muscle specific strength - data from the osteoarthritis initiative

Does radiographic knee OA status impact age-related reduction of thigh muscle specific strength - data from the osteoarthritis initiative

Analysis of anterior tibial subluxation to the femur at maximum extension in anterior cruciate ligament-deficient knees.

The factors affecting anterior tibial subluxation (ATS) have not yet been well examined. To assess the factors affecting ATS in anterior cruciate ligament (ACL)-deficient knees. One hundred twenty-four patients with unilateral ACL injuries were included. True lateral views of the ACL-deficient knee and contralateral normal knee were obtained during maximum extension using fluoroscopy under general anesthesia, and ATS was calculated as the side-to-side difference in the tibial position relative to the femur. Patients were divided into four groups according to the time from injury to surgery. To identify the factors affecting ATS, the following possible factors were assessed: (1) the time from injury to surgery, (2) presence of a medial meniscal injury, and (3) posterior tibial slope angle. There was a positive correlation between the ATS ratio and the time from injury to surgery ( r = 0.52). The ratio of the presence of a medial meniscus injury was significantly higher in patients who underwent anterior tibial subluxation reconstruction (ACL-R) more than 12 months after an injury than in other patients who underwent ACL-R within 12 months after an injury. The ATS ratio was significantly higher in patients with a medial meniscus injury than in those without a medial meniscus injury (5.6% vs. 4.1%). Our results suggested that ACL-R should be performed within 6 months after injury if surgeons prefer to avoid an increase in ATS in maximum knee extension and at the latest within 12 months to avoid medial meniscal injury at the time of ACL-R.

Return to Level I Sports After Anterior Cruciate Ligament Reconstruction: Evaluation of Age, Sex, and Readiness to Return Criteria.

Background:Return to sport (RTS) after anterior cruciate ligament (ACL) reconstruction is a topic of current interest. The high reinjury rates reported in younger athletes may be due in part to an early RTS.Purpose:To determine the proportion of athletes who return to level I (jumping, hard pivoting, and cutting) sport at less than 1 year after ACL reconstruction and compare return rates by age and sex. A secondary purpose was to examine whether RTS is associated with some commonly used outcome criteria.Methods:A cohort of 1440 athletes (992 males, 448 females) satisfied criteria for inclusion in this study (primary ACL reconstruction, normal contralateral knee, no additional surgery within the first year after the reconstruction, and participation in level I sport on a weekly basis prior to injury). The proportion of athletes in this sample who had resumed level I sport by 12 months after surgery was recorded, along with measurements of knee function (single-legged hop symmetry), laxity (KT-1000 arthrometer), and self-reported outcomes (International Knee Documentation Committee [IKDC] subjective score). Limb symmetry index scores of 90 or higher, side-to-side difference in anterior knee laxity of 2 mm or less, and IKDC scores of 95 or higher were considered indicators of satisfactory recovery from surgery.Results:Rates of return to level I sport were significantly higher for athletes aged 25 years and younger (48% return rate) compared with older athletes (26-35 years, 32% return rate [P < .0001]; ≥36 years, 19% return rate [P < .001]). Male athletes who were in the ≤25-year and 26- to 35-year age brackets had significantly higher return rates than female athletes (52% vs 39% and 37% vs 18%, respectively), whereas no sex-based differences in RTS were seen after 36 years of age. A significantly higher proportion of younger patients met the selected indicators of a satisfactory recovery. Regardless of age, athletes had twice the odds of RTS if they had limb symmetry index scores of 90 or higher (P ≤ .0001) and 3 times the odds of RTS if they had IKDC scores of 95 or higher (P < .0001).Conclusion:Almost half of younger athletes (aged ≤25 years) in the current cohort returned to level I sports within 12 months after ACL reconstruction. Younger athletes were also more likely to meet criteria that indicate a satisfactory functional recovery and that have been used to indicate readiness to RTS. There may be a role for adjusting thresholds for these criteria based on age.

The Incidence of Subsequent Meniscal Surgery Is Higher in the Anterior Cruciate Ligament–Reconstructed Knee Than in the Contralateral Knee

Background: A goal of anterior cruciate ligament (ACL) reconstruction is to provide a meniscal protective effect for the knee. Purpose: (1) To evaluate whether there was a different likelihood of subsequent meniscal surgery in the ACL-reconstructed knee or in the normal contralateral knee and (2) to compare the risk factors associated with subsequent meniscal surgery in the ACL-reconstructed knee and contralateral knee. Study Design: Cohort study; Level of evidence, 3. Methods: Using an integrated health care system’s ACL reconstruction registry, patients undergoing primary ACL reconstruction, with no meniscal injury at the time of index surgery and a normal contralateral knee, were evaluated. Subsequent meniscal tears associated with ACL graft revision were excluded. Subsequent meniscal surgery in either knee was the outcome of interest. Sex, age, and graft type were assessed as potential risk factors. Survival analysis was used to compare meniscal surgery–free survival rates and to assess risk factors of subsequent meniscal surgery. Results: Of 4087 patients, there were 32 (0.78%) patients who underwent subsequent meniscal surgery in the index knee and 9 (0.22%) in the contralateral knee. The meniscal surgery–free survival rate at 4 years was 99.08% (95% CI, 98.64%-99.37%) in the index knee and 99.65% (95% CI, 99.31%-99.82%) in the contralateral knee. There was a 3.73 (95% CI, 1.73-8.04; P < .001) higher risk of subsequent meniscal surgery in the index knee compared with the contralateral knee, or a 0.57% absolute risk difference. After adjustments, allografts (hazard ratio [HR], 5.06; 95% CI, 1.80-14.23; P = .002) and hamstring autografts (HR, 3.11; 95% CI, 1.06-9.10; P = .038) were risk factors for subsequent meniscal surgery in the index knee compared with bone–patellar tendon–bone (BPTB) autografts. Conclusion: After ACL reconstruction, the overall risk of subsequent meniscal surgery was low. However, the relative risk of subsequent meniscal surgery in the ACL-reconstructed knee was higher compared with the contralateral knee. Only graft type was found to be a risk factor for subsequent meniscal surgery in the ACL-reconstructed knee, with a higher risk for allografts and hamstring autografts compared with BPTB autografts.