Knee Laxity Measurements Research Articles

Anatomical fixation of tibial intercondylar eminence fractures in children using a threaded pin with an adjustable lock

IntroductionTibial intercondylar eminence fractures are a rare pathology causing anterior laxity of the knee, which requires anatomical reduction and a stable osteosynthesis. The aim of this study was to present the clinical results of reinsertion in anatomical position of these fractures, in the paediatric population, using a threaded pin with an adjustable lock. HypothesisOur hypothesis was that the clinical results would be satisfactory and comparable to the literature. MethodThis retrospective, monocentric study involved 34 consecutive patients with tibial intercondylar eminence fractures, divided into 55.9% with type 2, 35.2% with type 3, 8.8% with type 4 according to Meyers & McKeever, operated on between March 1999 and March 2018. Assessments were performed at a minimum follow-up of 1-year and included the Lysholm, subjective International Knee Documentation Committee (IKDC) and Tegner activity scores, and the measurement of anterior knee laxity by the KT1000. ResultsAt the average follow-up of 8.8 years, 7 patients were lost to follow-up, 2 required anterior cruciate ligament reconstruction. Pathological residual laxity was present in 25% of cases and instability in 16%. The average Lysholm score was 93.1±9.8, the average subjective IKDC was 93.8±6.4 and the average Tegner score was 5.6±1.5. The average anterior laxity of the knee was 0.7±2.0mm. ConclusionThe anatomical reinsertion using a threaded pin with an adjustable lock for tibial intercondylar eminence fractures in a paediatric population provides good functional results and is comparable to the data in the literature. Level of evidenceIV; retrospective.

The evaluation of Rolimeter, KLT, KiRA and KT-1000 arthrometer in healthy individuals shows acceptable intra-rater but poor inter-rater reliability in the measurement of anterior tibial knee translation

PurposeTo assess measurement equivalence, inter- and intra-rater reliability, standard error of measurements (SEM) and false positive measurements (FPM) of four different knee arthrometers (KLT,Karl Storz; KiRA, I + ; KT-1000 MEDmetric Corp; Rolimeter, Aircast) in healthy patients.MethodsFour different investigators (two advanced (AR) and two beginners (BR)) examined 12 participants with healthy knees at two time points with regards to anterior tibial translation (ATT) and side-to-side difference (SSD). Test equivalence was assessed using the TOST (two-one-sided t test) procedure with ± 1 mm equivalence boundaries. Intraclass correlation coefficients (ICCs) were calculated using two-way mixed effects models. Furthermore, false positive-(SSD > 3 mm) and SEMs were assessed.ResultsA total of 2304 Lachman Tests were performed. Between-rater SSDs were equivalent between AR and BR raters for the Rolimeter only. Inter-rater ICC values (SSD, ATT) were graded as “poor” to “moderate” for all devices. Equivalent test–retest results were observed for all raters using the Rolimeter, KLT and KT-1000, whereas measurement consistency with KiRA was given in the advanced examiners group only. Intra-rater ICC values (Range: SSD, ATT) were graded as “poor” to “moderate” for SSD values and “moderate” to “good” for ATT. SEMs were lowest for the Rolimeter and highest for KiRA. FPM were never obtained with the Rolimeter (0%), twice (2.1%) with the KT-1000, three times (3.1%) with the KLT and 33 times (34.4%) using KiRA.ConclusionThere is acceptable intra-rater but poor inter-rater reliability with all tested arthrometers. Measures of knee laxity are comparable between Rolimeter, KLT and KT-1000 but higher for KiRA. Clinically, the present study shows that repeated arthrometry measurements should always be performed by the same investigators.

Satisfactory outcome following arthroscopic fixation of tibial intercondylar eminence fractures in children and adolescents using bioabsorbable nails.

Tibial intercondylar eminence fracture is a rare fracture and is commonly treated with suture, screw or bio-absorbable nail. Current literature includes little information regarding outcome of surgically treatment with bio-absorbable nails. The purpose of this study was to report the clinical and functional outcomes in patients with tibial intercondylar eminence fractures arthroscopically treated with bio-absorbable nails. The study design was retrospective follow-up. Sixteen patients, age 11-16years, were surgically treated with bio-absorbable nail following an intercondylar eminence fracture. Thirteen patients participate in the present follow-up study. The median follow-up time was 6.5years. The main outcome measurement was the Knee Injury and Osteoarthritis Outcome Score (KOOS). Secondary outcome measurements consisted of: Eq5d-5L questionnaire, knee pain, knee laxity, range of motion (ROM), muscle strength, gait analyses, radiological outcomes, activity and level. The median KOOS scores for the five subscales were: pain 98.5 (19-100), symptoms 90.5 (54-100), ADL 100 (22-100), sport 87.5, (0-100) and QOL 88.0 (13-100), indication satisfactory outcome. Low level of gait asymmetry was observed. Almost balanced muscle strength between the injured and non-injured leg for knee extension and knee flexion strength was observed. Measurement of anterior knee laxity showed 12 patients with a knee laxity between -1 and 2mm. The examination of intercondylar eminence displacement at the time of follow-up showed that 12 patients had a displacement of 2mm or less. This case series demonstrates satisfactory patient-reported and functional outcomes in the treatment of intercondylar eminence fractures in children and adolescents with bio-absorbable nails.

Correlation of quality of life with instrumented analysis of a total knee arthroplasty series at the long-term follow-up.

The relationship between instrumented knee measurements and patient-reported outcome measures is a newer field that continues to evolve. The aim of this study was to evaluate long-term quality of life (QoL) post-total knee arthroplasty (TKA) surgery correlating validated self-reported questionnaires, clinical examination and instrumented analysis, using baropodometry and accelerometry. Thirty-six patients who underwent primary unilateral TKA between 1999 and 2006 were evaluated at 11.3 ± 2.3years following surgery. Clinical examination included range of motion (ROM) and instrumented knee laxity measurements with the Rolimeter device. The visual analogue scale (VAS) for pain was also recorded. The utilised subjective outcome scores were the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the short form of World Health Organisation Quality of Life (WHOQOL-BREF). Instrumented analysis was performed with baropodometry and accelerometry. QoL was assessed correlating clinical, subjective and instrumented results. Univariate analysis included the Spearman's Rho correlation coefficient and Mann-Whitney tests. At the long-term follow-up all patients had relatively high quality of life measurements, as well as functional scores, except for the Sport/Rec dimension of the KOOS score. Only cadence (p = 0.008) and velocity (p = 0.026) affected the WHOQOL psychology domain no matter the age, follow-up and gender of the patients. The domain wasunaffected by VAS and Rolimeter measurements. WHOQOL Social domain was unaffected by all instrumentation measurements except for stance phase (p = 0.025), VAS (p = 0.005) and ROM (p = 0.028). KOOS physical domain was not affected by any parameter. KOOS pain was reversely affected by VAS (p = 0.004), KOOS symptom by ROM (p = 0.000 and median maximum pressure (p = 0.033). Quality of life for the TKA patient can be correlated and assessed reliably with instrumented analysis using pedobarography and accelerometry, at the long-term follow-up. III.

Adjustable suspension versus hybrid fixation in hamstring autograft anterior cruciate ligament reconstruction

BackgroundThere has been increased use of adjustable suspensory fixation (ASF) for anterior cruciate ligament reconstruction (ACLR). Potential benefits are the ability to use a shorter graft and to prevent graft displacement and damage. The purpose of this study was to establish the efficacy of this fixation method and assess whether it leads to less tunnel widening, and avoids known complications of screw fixation. MethodsThirty-eight patients who underwent ACLR with ASF on both the femoral and tibial sides met the inclusion criteria and were propensity matched demographically with 38 patients who underwent hybrid fixation with femoral suspensory and tibial screw and sheath. At one-year, KT-1000 knee laxity measurements were recorded and detailed MRI analysis looking at tunnel aperture widening, tunnel appearance, graft integration within the tunnels, and graft healing. ResultsMRI comparison between ASF and hybrid cohorts revealed no significant differences in graft signal or integration, and clinically there were no differences in knee laxity between cohorts (mean 1.5 mm ± 2.0 and 1.5 mm ± 2.3 (n.s.) in the ASF and hybrid fixation respectively). Significantly less aperture tibial tunnel widening (2.2 mm versus 4.4 mm, p < 0.0001) and tibial cysts (2 versus 9, p = 0.047) were observed in the ASF cohort, whilst mean femoral tunnel widening was comparable between both cohorts (ASF 2.8 mm, hybrid 3.2 mm; n.s.). ConclusionsHamstring autografts for ACLR fixed using either ASF or a hybrid fixation technique provided comparable knee stability and MRI graft signal intensity. Tibial ASF demonstrated significantly less tibial aperture widening and tunnel cyst formation when compared to screw and sheath fixation.

O’Donoghue Sports Injury Award: Bridge-Enhanced ACL Repair is Non-Inferior to Autograft ACL Reconstruction at 2-Years: Results of a Prospective Randomized Clinical Trial

Objectives:Preclinical studies and an early clinical cohort study have suggested that for complete midsubstance ACL injuries, the technique of suture repair of the anterior cruciate ligament (ACL) augmented with a protein implant placed in the gap between the torn ends (bridge-enhanced ACL repair) may be a viable alternative to ACL reconstruction. We hypothesized that patients treated with bridge-enhanced ACL repair would have non-inferior patient reported outcomes and anteroposterior (AP) laxity, and superior hamstring strength at 2 years after surgery when compared with subjects who had ACL reconstruction with autograft.Study Design:Prospective Randomized Control Trial (NCT02664545).Methods:One hundred patients, ages 13 to 35, with complete mid-substance ACL injuries, were enrolled and underwent surgery within 45 days of injury. Sixty-five patients were randomized to receive a bridge-enhanced ACL repair (BEAR group) and 35 were randomized to receive autograft ACL reconstruction (ACLR group). Outcomes, including the International Knee Documentation Committee (IKDC) Subjective score, instrumented AP laxity and muscle strength were assessed at 2 years post-operatively. Both patients and assessors were blinded as to surgical assignment until after the 2-year assessment.Results:Ninety-six percent of the subjects returned for follow-up at 2 years. The median age of the subjects in both groups at enrollment was 17 years and the median pre-operative Marx score in both groups was 16 points. Non-inferiority criteria were met for both the IKDC subjective score and AP laxity. The BEAR group had significantly better recovery of hamstring strength than the ACLR group (p<0.001). The number of subjects who were reinjured and required a second ACL surgery was not statistically different between the two groups. Subjects who converted from BEAR to ACLR in the study period had outcomes at the 2-year point that were similar to those for subjects who had only a single ipsiateral ACL procedure (BEAR or ACLR).Conclusion:Bridge-enhanced ACL repair using a specific protein-based implant led to non-inferior outcomes to that of ACL reconstruction for patient reported and instrumented knee laxity measures at 2 years after surgery in a young and active cohort of patients with acute mid-substance ACL tears.

Objective measuring knee joint laxity in knee osteoarthritis using wearable sensors: a pilot study

Purpose: Knee Osteoarthritis (OA) is a degenerative joint disease, specifically degeneration of the cartilage leading to pain, stiffness, swelling, and tenderness. It is clinically understood that knee joint instability correlates to the onset of OA. The majority of current research on knee laxity is limited to subjective, self-reported questionnaires based on perceived instability or physician reported laxity based on manual manipulation of the knee. Research findings on objective measurements of knee laxity are limited therefore the purpose of our pilot work is to develop wearable sensors based system to quantify knee laxity in OA objectively, which is critical to understand the function of Knee OA. Methods: We used wearable sensors of measuring kinematics (the anterior-posterior placement of the tibia relative to the patella) and kinetics (the load applied to the tibia) to build measuring mechanism that the system is strapped to the anterior portion of the lower leg with one pad in contact with the patella and the other in contact with the tibia. Also a load handle is attached to the system. The displacement and load signals mentioned above are fed into a single board computer (SBC) utilizing microprocessor. This allows us to quantify the displacement of the tibia relative to the patella under various load conditions (-15, 15, 20, and 30 pounds). We obtained measurements of knee laxity in 5 knee OA patients (Age: 46-75; Gender: 4 Females, 1 Male; Body Weight: 57.2Kg-109.3Kg; Body Height: 1.46-1.78M). The knee laxity were compared between OA side and non-OA side using paired t-test at α=0.05. Results: We found that the laxity of OA side is significantly higher (4.902 +/- 2.734 mm) than non-OA side (3.530 +/- 2.170 mm) at the 30lbs load condition (P<0.05). Conclusions: This pilot study is designed to use wearable sensors to measure knee laxity objectively in knee OA. Our results are consistent with previous studies in a similar range. We believe our pilot study results suggest that the wearable system can be a portable solution to monitor knee joint function of knee OA patients in various clinical settings and their responses to different types of clinical treatments.

Cicatrisation des greffes de DT4 dans le tunnel tibial et dans l’échancrure : évaluation clinique et IRM à 4 ans minimum des DT4 fixés par fixation de suspension versus vis d’interférence

Success of ACL reconstruction requires Graft healing in the joint and a solid graft incorporation within the tunnels. Resorbable interference screws (RIS) provide limited tendon-bone contact because much of the tunnel circumference is occupied by the screw itself, while adjustable suspensory fixation (ASF) systems provide larger contact zones and stiffer fixation which favor graft healing. Purpose To evaluate ligamentization of four-strand semitendinosus (4ST) using MRI, fixed with ASF compared to RIS. Study Design Prospective comparative study; Level II. Methods The authors prospectively enrolled 57 patients undergoing primary ACL reconstruction using single bundle 4ST. The femoral graft was fixed using suspensory fixation in all knees. The tibial graft was fixed using ASF in 28 knees and using RIS in 29 knees. The groups were similar in term of age and gender. Minimum 4 years postoperatively, GNRB® knee laxity measurements were taken and MRI scans were performed to assess graft incorporation within the tibial tunnel and in the notch. Results There was not significant difference on the Functional results IKDC and Lysholm. The IKDC Global score A + B 96.4 % was better in the ASF group than in RIS 82.1 % (p = 0.04). Mean side to side Laximetry test was none significant p = 0.18 (−0.13 vs 0.35). Tunnel enlargement was no significant between the two groups 10.7 mm in ASF group and 11.5 mm in RSI group. Howell graft signal assessment in the notch was excellent (Grade I + II) in 91 % of cases in the ASF Group and in 73 % of cases in the RIS group (p = 0.04). In the tibia the SNQ was 2.25 ± 4.05 in the ASF group and 10.28 ± 18.98 in the RIS group (p = 0.02). In the notch the SNQ was 2.57 ± 2.80 in the ASF group and 6.62 ± 10.99 in the RIS group (ns). There were 6 consistent tibial cysts related to the screw (20 %) in the RSI group and no cyst in the ASF group. Conclusion ASF provides more favorable conditions than RIS for incorporation and ligamentization of 4ST grafts within the tibial tunnel with more residual cysts in the RSI group. In the notch, the Howell grade was better in the ASF group, although the SNQ were not significatively better. the objective IKDC Score was significatively better in ASF group, however functionals results are similar.

Anterior and Rotational Knee Laxity Does Not Affect Patient-Reported Knee Function 2 Years After Anterior Cruciate Ligament Reconstruction

Background: While a primary goal of anterior cruciate ligament (ACL) reconstruction is to reduce pathologically increased anterior and rotational knee laxity, the relationship between knee laxity after ACL reconstruction and patient-reported knee function remains unclear. Hypothesis: There would be no significant correlation between the degree of residual anterior and rotational knee laxity and patient-reported outcomes (PROs) 2 years after primary ACL reconstruction. Study Design: Cross-sectional study; Level of evidence, 3. Methods: From a prospective multicenter nested cohort of patients, 433 patients younger than 36 years of age injured in sports with no history of concomitant ligament surgery, revision ACL surgery, or surgery of the contralateral knee were identified and evaluated at a minimum 2 years after primary ACL reconstruction. Each patient underwent Lachman and pivot-shift evaluation as well as a KT-1000 arthrometer assessment along with Knee injury and Osteoarthritis Outcome Score and subjective International Knee Documentation Committee (IKDC) scores. A proportional odds logistic regression model was used to predict each 2-year PRO score, controlling for preoperative score, age, sex, body mass index, smoking, Marx activity score, education, subsequent surgery, meniscal and cartilage status, graft type, and range of motion asymmetry. Measures of knee laxity were independently added to each model to determine correlation with PROs. Results: Side-to-side manual Lachman differences were IKDC A in 246 (57%) patients, IKDC B in 183 (42%) patients, and IKDC C in 4 (<1%) patients. Pivot-shift was classified as IKDC A in 209 (48%) patients, IKDC B in 183 (42%) patients, and IKDC C in 11 (2.5%) patients. The mean side-to-side KT-1000 difference was 2.0 ± 2.6 mm. No significant correlations were noted between pivot-shift or anterior tibial translation as assessed by Lachman or KT-1000 and any PRO. All predicted differences in PROs based on IKDC A versus B pivot-shift and anterior tibial translation were less than 4 points. Conclusion: Neither the presence of IKDC A versus B pivot-shift nor increased anterior tibial translation of up to 6 mm is associated with clinically relevant decreases in PROs 2 years after ACL reconstruction.

Posturography table is a good test to evaluate the anterior cruciate Ligament reconstruction?

Introduction: The success of anterior cruciate ligament reconstruction (ACLR) is assessed using subjective and functional scores, as well as measurements of knee laxity. The latter is often quantified using instrumented laximetry devices, which measure ‘static’ anterior tibial translation, though recent studies suggested more comprehensive “dynamic” analyses such as jump tests. To facilitate and improve dynamic stability analyses, a proprioception table was adapted to evaluate knees before and after ACLR, though the accuracy and pertinence of its measurement have not yet been demonstrated. Objectives: To determine whether proprioceptive analysis following ACLR provides meaningful and helpful information to guide surgeons and physiotherapists with postoperative rehabilitation and return to sports. Methods: We conducted a prospective study, on a population of 50 amateur or professional sports patients, who received ACLR by the one surgeon (FW). Preoperative and 6-months assessments included GnRB laxity analysis and proprioceptive dynamic stability analysis, with evaluation of the bearing area under 6 different conditions: open eyes (C1), closed eyes (C2), vision distorted by virtual reality headset (C3), open eyes on unstable support (C4), closed eyes on unstable support (C5) and distorted vison on unstable support (C6); a calculation of the C4/C1 ratio enabled appreciation of visual compensations in the proprioceptive capacity, and dependence on visual inference (low ratios indicate greater recourse to visual afference). A complementary analysis of muscular strength by isokinetic assessment was also performed at 6 months followup. Results: There was a significant improvement in proprioception table stability at 6 months compared to the preoperative condition at the C4 (470 vs 440 mm2), C5 (1710 vs 1315 mm2) and C6 (1330 vs 1210 mm2) assessments. For 32 patients evaluated by GnRB, differential laxity at 6 months was less than 5 mm at 200 N, and isokinetic muscle strength measurement was less than 20% different between the knee healthy and the operated knee, or between quadriceps and hamstrings. Proprioceptive quality was variable, with significant visual offsets in some cases (C4/C1 ratio, 0.5 to 16.2). Conclusion: Patients, who have good results in laximeter tests and isokinetic muscle strength measurement, may have a poor proporioception quality with significant visual offsets. The proprioception analysis at 6 months following ACLR could therefore be important to consider rehabilitation and sports recovery.

Personalised 3D knee compliance from clinically viable knee laxity measurements: A proof of concept ex vivo experiment

Personalised information of knee mechanics is increasingly used for guiding knee reconstruction surgery. We explored use of uniaxial knee laxity tests mimicking Lachman and Pivot-shift tests for quantifying 3D knee compliance in healthy and injured knees. Two healthy knee specimens (males, 60 and 88 years of age) were tested. Six-degree-of-freedom tibiofemoral displacements were applied to each specimen at 5 intermediate angles between 0° and 90° knee flexion. The force response was recorded. Six-degree-of-freedom and uniaxial tests were repeated after sequential resection of the anterior cruciate, posterior cruciate and lateral collateral ligament. 3D knee compliance (C6DOF) was calculated using the six-degrees-of-freedom measurements for both the healthy and ligament-deficient knees and validated using a leave-one-out cross-validation. 3D knee compliance (CCT) was also calculated using uniaxial measurements for Lachman and Pivot-shift tests both conjointly and separately. C6DOF and CCT matrices were compared component-by-component and using principal axes decomposition. Bland–Altman plots, median and 40–60th percentile range were used as measurements of bias and dispersion. The error on tibiofemoral displacements predicted using C6DOF was < 9.6% for every loading direction and after release of each ligament. Overall, there was good agreement between C6DOF and CCT components for both the component-by-component and principal component comparison. The dispersion of principal components (compliance coefficients, positions and pitches) based on both uniaxial tests was lower than that based on single uniaxial tests. Uniaxial tests may provide personalised information of 3D knee compliance.

Preoperative and Intraoperative Predictors of Long-Term Acceptable Knee Function and Osteoarthritis After Anterior Cruciate Ligament Reconstruction: An Analysis Based on 2 Randomized Controlled Trials

To determine preoperative predictors of long-term acceptable knee function and the development of osteoarthritis (OA) in long-term follow-up after anterior cruciate ligament (ACL) reconstruction. This study is a long-term follow-up of 2 previous randomized controlled trials that included 193 patients who underwent unilateral ACL reconstruction with ipsilateral hamstring tendon or patellar tendon autografts. Patients who suffered multiligament injuries, major meniscal injuries, chondral lesions requiring surgical treatment, or had a previous ACL reconstruction were excluded. Patient demographics, preoperative clinical assessments, and intraoperative findings were used to create stepwise multivariable regression models to determine the patient-acceptable symptom state (PASS) in the International Knee Documentation Committee and the development of OA defined as a Kellgren-Lawrence grade ≥2. Knee laxity measurements, hop performance, patient-reported outcome, and concomitant injuries were determined as variables. A total of 147 patients (63.7% men) were eligible for inclusion, with a mean follow-up of 16.4 ± 1.3years. The patients were an average age of 27.9 ± 8.3years at the time of ACL reconstruction. One-half of the cohort reported an International Knee Documentation Committee evaluation system score above the PASS cutoff. The presence of a concomitant injury at operation (odds ratio [OR], 2.61; 95% confidence interval [CI], 1.10-6.21; P= .030) and greater preoperative anteroposterior laxity (OR, 1.87; 95% CI, 1.05-3.35; P= .034) increased the likelihood of achieving a PASS. A longer period between ACL injury and reconstruction (OR, 2.25; 95% CI, 1.02-5.00; P= .046) and older age at reconstruction (OR, 2.28; 95% CI, 1.34-3.86; P= .0023) increased the odds of developing OA at follow-up. Patients who were older at the time of ACL reconstruction and had waited >1year between the injury and reconstruction ran an increased risk of having OA 16years after reconstruction. One in 2 patients reported acceptable long-term knee function, but no risk factor for poorer subjective knee function was identified. Patients who had a minor concomitant injury and increased preoperative anteroposterior knee laxity had increased odds of reporting an acceptable long-term knee function. Level II; prospective comparative study.

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.

Outcomes after bone grafting in patients with and without ACL revision surgery: a retrospective study

BackgroundCurrent literature is lacking of data regarding functional outcomes in patients following bone tunnel grafting with or without revision anterior cruciate ligament (ACL) reconstruction. Therefore, the aim of the present study was to evaluate the clinical outcome in patients with (RACL) or without revision ACL reconstruction (OBG) following bone grafting.MethodsFifty-nine patients (18 female, 41 male) who underwent bone grafting due to recurrent, symptomatic ACL deficiency following ACL reconstruction between 2011 and 2014 were retrospectively analyzed. In 44 patients (mean age: 30,5 ± 8,5 years) a staged revision ACL reconstruction (RACL) was performed after bone grafting. 10 patients (mean age: 33.2 ± 10.3 years) refused to have ACL revision surgery after bone grafting (OBG). Outcome measures included instrumented laxity testing, the International Knee Documentation Committee (IKDC) score, the Knee Injury and Osteoarthritis Outcome Score (KOOS), Lysholm score and Tegner activity scale.ResultsAfter mean period of 33,9 ± 17.0 months, 54 patients were available for follow up examination. In the RACL group, the Lysholm score was 77,2 ± 15,5 (range 35–100), the mean IKDC subjective knee score was 69,0 ± 13,4 (range 39,1–97,7) and the mean Tegner activity score was 4,1 ± 1,5 (range, 1–9). Similarly, in the OBG group the mean Lysholm score was 72,90 ± 18,7 (range 50–100), the mean IKDC subjective score was 69,3 ± 20,0 (range 44,1–100) and the mean Tegner activity score was 4,6 ± 1,2 (range, 3–6). No significant difference was observed between the two groups. Knee laxity measurements were elevated without revision ACL surgery, however the difference was not significant.ConclusionBone tunnel grafting with or without second stage ACL revision surgery showed no significant difference in functional outcome score. Thus, in case of revision ACL instability careful patient selection is necessary and expectations should be discussed openly with the patients.

No Difference in the KOOS Quality of Life Subscore Between Anatomic Double-Bundle and Anatomic Single-Bundle Anterior Cruciate Ligament Reconstruction of the Knee: A Prospective Randomized Controlled Trial With 2 Years’ Follow-up

Background: The double-bundle reconstruction technique was developed to resemble the properties of the native anterior cruciate ligament (ACL) more closely than the conventional single-bundle technique. The clinical benefit of the operative procedure is controversial, and there is a need for studies with a focus on patient-reported outcomes (PROs). Study Design: Randomized controlled trial; Level of evidence, 1. Hypothesis: Anatomic double-bundle ACL reconstruction would be superior to anatomic single-bundle reconstruction regarding the change in the Knee injury and Osteoarthritis Outcome Score (KOOS) Quality of Life (QoL) subscore from baseline to 2-year follow-up. Methods: According to sample size calculations, 120 patients aged 18 to 40 years with a primary ACL injury of their knee were randomized to the anatomic double-bundle or anatomic single-bundle reconstruction groups. Patients with posterior cruciate ligament, posterolateral corner, or lateral collateral ligament injuries or with established osteoarthritis were excluded. Patients with residual laxity from a coexistent medial collateral ligament injury were excluded. Data were registered at baseline, 1 year, and 2 years. In 24 patients, postoperative 3-dimensional computed tomography was performed to verify the positioning of the bundles. The outcome measures were the change in KOOS subscores and the International Knee Documentation Committee 2000 subjective score, pivot-shift test result, Lachman test finding, KT-1000 arthrometer measurement, activity level, return-to-sports rate, and osteoarthritic changes on radiographs. A linear mixed model was used for the analysis of all the PROs, including the primary outcome. Results: The change in the KOOS QoL subscore from baseline to 2-year follow-up was not different between the double- and single-bundle groups (mean change, 29.2 points vs 28.7 points, respectively; –0.5-point difference; 95% CI, –8.4 to 7.4 points; P = .91). Neither were there any differences between the 2 groups in the remaining PROs, knee laxity measurements, or activity levels of the patients. Radiological signs of osteoarthritis were found in 2 patients. Eleven patients had a graft rupture: 8 in the single-bundle group and 3 in the double-bundle group (P = .16). Three-dimensional computed tomography of the knees verified the positioning of the anteromedial bundle, posterolateral bundle, and single-bundle grafts to be within acceptable limits. Conclusion: There was no difference in the KOOS QoL subscore, the remaining PROs, knee laxity measurements, or activity levels comparing the double- and single-bundle ACL reconstruction techniques. The number of bundles does not seem to influence clinical and subjective outcomes, as long as the tunnels are adequately positioned. Registration: NCT01033188 (ClinicalTrials.gov identifier).

Increased knee laxity with hamstring tendon autograft compared to patellar tendon autograft: a cohort study of 5462 patients with primary anterior cruciate ligament reconstruction

PurposeTo compare anterior knee laxity and patient-reported outcome measures (PROMs) between anterior cruciate ligament reconstruction (ACLR) performed with bone–patellar tendon–bone (BPTB) and hamstring tendon (HT) autografts and, moreover, to study any correlation between postoperative anterior knee laxity and PROMs.MethodsPatients who underwent primary ACLR at Capio Artro Clinic, Stockholm, Sweden, from January 2000 to October 2015, were identified in our local database. Instrumented laxity measurements and PROMs were reviewed. The KT-1000 arthrometer, with an anterior tibial load of 134-N, was used to evaluate knee laxity preoperatively and at the 6-month follow-up. The Lysholm score was collected preoperatively and at 6 months postoperatively. The Knee injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and at the 1-year follow-up.ResultsA total of 5462 primary ACLRs, 692 BPTBs and 4770 HT autografts were included in the study. All the patients showed a significant reduction in knee laxity from preoperatively to postoperatively (BPTB group: from 3.8 ± 2.6 to 1.2 ± 2.1 mm; HT group: from 3.6 ± 3.1 to 1.8 ± 2.2 mm; P < 0.001 for both). The HT group showed a significantly increased postoperative knee laxity compared with the BPTB group (1.8 ± 2.2 vs 1.2 ± 2.1 mm; P < 0.001). The mean anterior tibial translation (ATT) reduction from preoperative to postoperative was significantly larger for the BPTB graft compared with the HT graft (2.7 ± 2.2 vs 1.7 ± 2.6 mm; P < 0.001). A significantly higher rate of “surgical failures”, defined as a postoperative side-to-side (STS) difference > 5 mm, was found in the HT group compared with the BPTB group at follow-up (4.3 vs 2.4%; P < 0.001). A significantly larger improvement was found in the HT group compared with the BPTB group for the KOOS Pain (9.5 vs 8.0; P = 0.02), Activities of Daily Living (7.2 vs 5.7; P = 0.006), Sports (24.2 vs 15.3; P < 0.001) and Quality of Life (25.8 vs 22.1; P = 0.001) subscales. No significant difference regarding the mean improvement in the Lysholm knee score was found between the two grafts (BPTB group: 14.5, HT group: 14.0; n.s.). No correlation between postoperative anterior knee laxity and PROMs was found in either graft group.ConclusionPrimary ACLR performed with HT autograft resulted in greater postoperative anterior knee laxity and significantly more surgical failures (STS > 5 mm) compared with BPTB autograft. The BPTB autograft showed a larger anterior knee laxity reduction (ATT reduction) in conjunction with primary ACLR. The HT autograft led to a significantly larger improvement in four of five KOOS subscales from preoperatively to the 1-year follow-up, compared with BPTB autograft. There was no association between postoperative anterior knee laxity and PROMs for either graft. The findings of the present study provide clinicians with valuable information regarding differences in knee laxity and subjective knee function between BPTB and HT autograft after primary ACLR. The use of BPTB autograft should be considered for patients with high knee stability demands.Level of evidenceRetrospective cohort study, Level III.

Bicruciate lesion biomechanics, Part1-Diagnosis: translations over 15mm at 90° of knee flexion are indicative of a complete tear.

Understanding the pathomechanics of a bicruciate injury (BI) is critical for its correct diagnosis and treatment. The purpose of this biomechanical study aims to quantify the effects of sequential sectioning of the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL)bundles on knee laxity. Twelve cadaveric knees (six matched pairs) were used. Knee laxity measurements consisted of neutral tibial position, anterior-posterior translation, internal-external rotation, and varus-valgus angulation in different conditions: intact, ACL cut, incomplete BI (divided into two groups: anterolateral (AL) bundle intact or posteromedial (PM) bundle intact) and complete bicruciate tear. Data were collected using a Microscribe system at 0°, 30°, 60°, and 90° of knee flexion. In comparison to the intact knees, incomplete BI and complete BI showed a significant increase of total antero-posterior tibial translation. The largest significant increase was observed at 90° of flexion after a complete bicruciate resection (p < 0.001). A threshold difference greater than 15mm from the intact could be used to identify a complete BI from an incomplete BI evaluating the total antero-posterior translation at 90°. All sectioned states had significant increases compared with the intact condition in internal-external rotation and varus-valgus stability at all tested flexion angles. Both incomplete and complete BI led to an important AP translation instability at all angles; however, full extension was the most stable position at all injured models. Total antero-posterior translation at 90° of knee flexion over 15mm, in comparison to the intact condition, was indicative of a complete BI. Since the appropriate assessment of a combined ACL and PCL lesion remains a challenge, this study intends to assist its diagnosis. As BI's main antero-posterior instability occurred at 90°, a total antero-posterior drawer test is proposed to evaluate BI in the clinical setting. Total antero-posterior translation at 90° > 15mm, in comparison to the intact condition or the contra-lateral non-injured knee, can be used to identify a complete from an incomplete BI.

Anterior laxity of the knee assessed with gravity stress radiograph.

To clarify the advantage of prone position over supine position in radiographically-demonstrating anterior knee laxity measurement for anterior cruciate ligament (ACL) injury, and to optimize the radiographic technique for the ACL-deficient knees in a clinical setting. Thirty-nine patients with unilateral ACL injury had consented to participate in this study. They were divided into two groups and subjected to the different radiographic evaluations: study 1 (20 patients); supine versus prone position with knee full-extended, and study 2 (19 patients); comparison of (1) prone position with knee full-extended (FPV), (2) prone position with knee flexed at 15° (AGV), and (3) supine position with calf put on a board at 15° of knee flexion (SGV). Lateral radiographs for both knees were taken and were measured the side-to-side difference of tibial position related to femur. In study 1, the side-to-side difference was 2.8 ± 1.0mm in supine position and 4.3 ± 2.1mm in prone position, showing a statistically significant difference. In study 2, the side-to-side difference was 3.7 ± 2.4mm in FPV, 4.6 ± 2.0mm in AGV, and 4.2 ± 2.8mm in SGV, while the difference in the latter two positions was larger than that in FPV. The anterior laxity in prone position is larger than that in supine position for ACL injury. Moreover, the gravity-assisted lateral radiograph in prone position with knee flexed at 15° could be one of the preferable radiographic techniques and could provide more information than the simple radiograph.

Anterior tibial laxity using the GNRB® device in healthy knees

BackgroundGRNB® 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 methodsWe 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). ResultsThere 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). ConclusionThe 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.

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

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