Influence of selected plane on the evaluation of tibial tunnel locations using a three-dimensional bone model in double-bundle anterior cruciate ligament reconstruction

BackgroundThe purpose of this study was to investigate the influence of a selected plane on the evaluation of tibial tunnel locations following anterior cruciate ligament reconstruction (ACLR) between two planes: the plane parallel to the tibial plateau (Plane A) and the plane perpendicular to the proximal tibial shaft axis (Plane B).MethodsThirty-four patients who underwent double-bundle ACLR were included. Three-dimensional model of tibia was created using computed tomography images 2 weeks postoperatively, and tibial tunnels of the anteromedial bundle (AMB) and posterolateral bundle (PLB) were extracted. To evaluate tibial tunnel locations, two planes (Planes A and B) were created. The locations of the tibial tunnel apertures of each bundle were evaluated using a grid method and compared between Planes A and B. The difference in coronal alignment between Planes A and B were also assessed.ResultsThe AMB and PLB tunnel apertures in Plane A were significantly more laterally located than in Plane B (mean difference; AMB, 1.5%; PLB, 1.7%, P < 0.01). There were no significant differences in the anteroposterior direction between the planes. Coronal alignment difference between the planes was 16.8 ± 2.2°; Plane B was more valgus than Plane A.ConclusionAlthough tibial tunnel locations were not significantly influenced by the selected planes in the AP direction, subtle but statistically significant differences were found in the ML direction between the Planes A and B in double-bundle anterior cruciate ligament reconstruction. The findings suggest that both Planes A and B can be used in the assessment of tibial tunnel locations after anterior cruciate ligament reconstruction.     

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.     

Quantifying graft impingement in anterior cruciate ligament reconstruction

BackgroundAnterior cruciate ligament reconstructions (ACLR) fail at a rate of 10–15%, with graft impingement often a cause. In this study we investigate the prevalence and causes of impingement seen during ACLR surgery.MethodsWe reviewed consecutive primary ACLR from 2012-2018. Graft impingement was estimated intraoperatively by placing the arthroscope through the tibial tunnel and passively extending the knee, observing how much was obscured by the lateral femoral condyle from an anterior and lateral direction. Preoperative MRI scans were used to measure the intercondylar notch; Notch Width Index (NWI) and Notch Depth Index (NDI). Positioning of the tunnels was determined on postoperative radiographs.ResultsThere were 283 ACLRs performed with 33 failures diagnosed on MRI (11.7%). 257 patients had complete imaging and follow up (91%). The mean age was 28 (±9) years and mean follow-up 5.3 (±1.8) years. The mean NWI was 0.26(±0.03), and NDI was 0.49(±0.06). The tibial tunnel aperture was located 42(±6) % of the way from anterior-posterior and 39(±6) % from medial-lateral. Impingement requiring a notchplasty was observed in 80% of cases, with lateral impingement more prominent.ConclusionsThe amount of impingement did not correlate with tunnel position, which was located within the recommended area. There was a weak negative correlation between NWI and lateral impingement (r_s = −0.16, p = 0.01), and NDI and anterior impingement (r_s = −0.12, p = 0.04), therefore a smaller notch is associated with greater impingement. Despite optimal tunnel positioning, impingement still occurs in a significant number of cases therefore notchplasty should always be considered to keep revision rates low.     

Quadriceps muscle compensatory activations are delayed following anterior cruciate ligament reconstruction using hamstring tendon graft

BackgroundCompensatory and anticipatory quadriceps activation (CQA and AQA) in response to postural perturbations are essential for functional stability of the knee. This study aimed at investigating CQA and AQA before and after anterior cruciate ligament reconstruction (ACLR) using hamstrings graft.MethodsTwelve participants with ACLR and 12 healthy controls were exposed to 10 either unpredictable or predictable perturbations of the knee before ACLR (T1), two months (T2) and six months (T3) after surgery. Latencies of CQA and AQA in vastus lateralis (VL), rectus femoris (RF) and vastus medialis (VM) were measured.ResultsLatency of CQA was delayed in ACLR compared to controls at T1 for VL (105 ± 25 vs. 57 ± 9 ms; P < .001), RF (102 ± 23 vs. 56 ± 9 ms; P < .001) and VM (107 ± 24 vs. 66 ± 16 ms; P < .001), at T2 for VL (68 ± 14 vs. 55 ± 10 ms; P < .01) and at T3 for VL (105 ± 22 vs. 58 ± 7 ms; P < .001), RF (102 ± 22 vs. 58 ± 12 ms; P < .001) and VM (106 ± 20 vs. 63 ± 8 ms; P < .001). AQA occurred earlier in ACLR than in controls at T1 for VL (− 82 ± 64 vs. − 14 ± 11 ms; P < .05) and VM (− 105 ± 68 vs. -9 ± 12 ms; P < .05).ConclusionCQA are delayed following ACLR with hamstring graft and should be addressd by post-surgical rehabilitation.     

Referencing the substitute anteroposterior line of the tibia improves rotational alignment of the tibial component in medial unicompartmental knee arthroplasty

BackgroundThere is no consensus regarding how best to determine the tibial rotational alignment in unicompartmental knee arthroplasty (UKA). The purpose of this study was to clarify whether using the substitute anteroposterior (sAP) line of the tibia, as has recently been proposed, can improve tibial rotation.MethodsThe study included 57 consecutive medial UKAs. From May 2015 to September 2016, 28 knees in 28 patients underwent UKA using the medial intercondylar ridge (MIR) line as the tibial anteroposterior (AP) reference (MIR group). From October 2016 to March 2018, 29 knees in 29 patients underwent UKA using the sAP line (sAP group). In both groups, the external rotation angle of the tibial component relative to a line perpendicular to the surgical epicondylar axis was measured using computed tomography-based three-dimensional preoperative planning software for TKA and UKA.ResultsThe mean external rotation angles of the tibial component in the MIR and sAP groups were 5.2° ± 8.5° (range, − 12.4° to 20.8°) and 0.7° ± 3.2° (range, − 6.0° to 7.4°), respectively (unpaired t test, P = 0.014). The variation in the external rotation angle of the tibial component was significantly smaller in the sAP group than in the MIR group (F test, P < 0.0001), as was the number of the outliers with more than ± 5° error (Fisher's exact test, P < 0.0001).ConclusionsThe use of the sAP line as the AP reference could improve and stabilize the rotational orientation of the tibial component in UKA procedures.     

Focal proximal fibular angle: A potential indicator of the tibial mechanical axis in opening-wedge high tibial osteotomy

BackgroundFor opening-wedge high tibial osteotomy, correct alignment is essential for a better prognosis. It is difficult to evaluate the mechanical axis of the lower extremity or tibia using a single fluoroscopic image. This study aimed to discuss the use of focal proximal fibular angle (FPFA), which can be assessed by a single fluoroscopic image, as an intraoperative indicator.MethodsEligible for analyses were 111 consecutively treated patients; for the final analyses 96 patients were included. The preoperative and postoperative medial proximal tibial angle (MPTA) and FPFA were measured. The relationship between these two angles, correction amount, weight-bearing line ratio and patient characteristics were analyzed.ResultsThe preoperative FPFA and MPTA were 96.5 ± 3.8° (mean ± standard deviation, SD) and 84.8 ± 3.0°, while the postoperative FPFA and MPTA were 87.6 ± 4.1° and 94.0 ± 3.5°, respectively. The preoperative and postoperative sums of the MPTA and FPFA were constant. The discrepancy was less than 3° in all knees, less than 2° in 92.7% knees and less than 1° in 68.8% knees. It was not correlated with age, sex, weight-bearing line ratio, or correction amount.ConclusionThe study findings confirmed the constancy of the sum of the MPTA and FPFA. The FPFA can be easily evaluated on a single fluoroscopic image of the knee. Use of the FPFA as guidance may simplify the procedure of opening-wedge high tibial osteotomy and approximately predict the tibial mechanical axis.     

Accuracy of a hand-held surgical navigation system for tibial resection in total knee arthroplasty

BackgroundAccuracy of total knee arthroplasty (TKA) implant placement and overall limb are important goals of TKA technique.MethodsThe accuracy and ease of use of an accelerometer-based hand-held navigation system for tibial resection during TKA was examined in 90 patients. Preoperative goals for sagittal alignment, navigation system assembly time, resection time, and tourniquet time were evaluated. Coronal and sagittal alignment was measured postoperatively.ResultsThe average coronal tibial component alignment was 0.43° valgus; 6.7% of patients had tibial coronal alignment outside of ± 3° varus/valgus. The difference between the intraoperative goal and radiographically measured posterior tibial slope was 0.5°. The average time to completion of the tibial cut was 4.6 minutes.ConclusionThe accelerometer-based hand-held navigation system was accurate for tibial coronal and sagittal alignment during TKA, with no additional surgical time compared with conventional instrumentation.     

Comparison between navigated reported position and postoperative computed tomography to evaluate accuracy in a robotic navigation system in total knee arthroplasty

BackgroundComputer navigation increases reproducibility compared to non-navigated total knee arthroplasty (TKA). Robotics navigation is a branch of computer navigation technology that might further improve accuracy of implant placement. The aim of this study is to assess the accuracy achieved in TKA with a robotic navigation system.MethodsOne hundred seventy three knees. System studied: Omni navigation System (OMNI, Raynham, MA). Navigated femoral and tibial cuts were compared to postoperative computed tomography (CT). Measurements reviewed: femoral coronal alignment (FCA), femoral sagittal alignment (FSA), femoral rotational alignment (FRA), tibial coronal alignment (TCA), tibial sagittal alignment (TSA) and hip–knee–ankle (HKA) angle. Statistical analysis was made using R.ResultsThe mean differences between the navigated reported and the CT positions were: FCA: 0.1 ± 1.2° more varus (P = 0.58), FSA: 1.5 ± 0.3° more flexed (P < 0.001), FRA: 0.0 ± 1.7° (P = 0.93), TCA: 0.7 ± 1.1° more varus (P < 0.001), TSA: − 1.3 ± 1.5 more negative slope (P < 0.001), HKA angle: 0.4 ± 2.4 more varus (P < 0.049).The percentages of concordance inside a three degree difference were: FCA: 98% (169 knees), FSA: 100% (173 knees), FRA: 94% (162 knees), TCA: 99% (171 knees), TSA: 93% (161 knees) and HKA angle: 83% (144 knees).ConclusionsThe current study showed that the robotic navigation system studied is highly accurate regarding final implant positioning for FCA, FRA and TCA. It has less accuracy in FSA, TSA and the HKA angle.     

Tibial tunnel widening after hamstring anterior cruciate ligament reconstructions: Comparison between Rigidfix and bio-Transfix

BackgroundThere is no study comparing tibial tunnel widening after hamstring anterior cruciate ligament (ACL) reconstructions between RigidFix(r) and Bio-TransFix(r).MethodsHamstring ACL reconstructions using RigidFix(r) in 56 patients and Bio-TransFix(r) in 41 with a minimum of 2 years postoperative evaluation were reviewed. Tibial fixation was performed using Intrafix in both groups. On the anterior–posterior (AP) and lateral radiographs, the diameter of the tibial tunnel was measured at proximal, middle, and distal positions. Postoperative laxity evaluations were performed using Lachman test, pivot-shift test, and instrumented laxity testing using the KT-1000 arthrometer.ResultsOn the AP and lateral radiographs, the average diameter of the tibial tunnel in the Bio-TransFix(r) group significantly increased after 6 months compared to the immediate postoperative measurement (p = 0.002 and p = 0.002, respectively). However, the average diameter of the tibial tunnel in the RigidFix(r) group did not increase after 6 months compared to the immediate postoperative measurement. Tunnel widening at 12 months postoperatively in the Bio-TransFix(r) group was significantly more than that of the RigidFix(r) group on AP and lateral radiographs (p = 0.012 and 0.016, respectively). Tunnel widening at 24 months postoperatively showed a significant difference between the two groups (p = 0.000 and 0.000, respectively). Fifteen patients (36.6%) in the Bio-TransFix(r) group and 15 patients (26.8%) in the RigidFix(r) group showed tunnel widening. There were no significant differences in results of the Lachman and pivot-shift tests, and mean KT-1000 measurement between the two groups.ConclusionThe Bio-TransFix(r) group showed progressive tibial tunnel widening after 6 months postoperatively but no clinical signs of instability.Level of evidenceLevel III.     

Young athletes after ACL reconstruction with asymmetric quadriceps strength at the time of return-to-sport clearance demonstrate drop-landing asymmetries two years later

BackgroundQuadriceps strength asymmetry at the time of return-to-sport (RTS) after anterior cruciate ligament reconstruction (ACLR) contributes to altered landing mechanics. However, the impact of RTS quadriceps strength on longitudinal alterations in landing mechanics, a risk factor for poor knee joint health over time, is not understood. The purpose of this study was to test the hypothesis that young athletes with quadriceps strength asymmetry at the time of RTS clearance after ACLR would demonstrate asymmetric landing mechanics 2 years later compared to those without quadriceps strength asymmetry.MethodsWe followed 57 young athletes (age at RTS = 17.6 ± 3.0 years; 77% females) with primary, unilateral ACLR for 2 years following RTS clearance. At RTS, we measured isometric quadriceps strength bilaterally and calculated limb-symmetry indices [LSI = (involved/uninvolved)×100%]. Using RTS quadriceps LSI, we divided participants into High-Quadriceps (HQ; LSI ≥ 90%) and Low-Quadriceps (LQ; LSI < 85%) groups. Two years later, we assessed landing mechanics during a drop-vertical jump (DVJ) task using three-dimensional motion analysis. We compared involved/uninvolved limb values and LSI between the HQ and LQ groups using Mann-Whitney U tests.ResultsThe LQ group (n = 26) demonstrated greater asymmetry (lower LSI) during landing at 2 years post-RTS for knee flexion excursion (p = 0.016) and peak vertical ground reaction force (p = 0.006) compared to the HQ group (n = 28). There were no group differences in uninvolved or involved limb values for all variables (all p > 0.093).ConclusionYoung athletes after ACLR with quadriceps strength asymmetry at the time of RTS favored the uninvolved limb during DVJ landing 2 years later. These landing asymmetries may relate to long-term knee joint health after ACLR.     

Limb and component alignment after total knee arthroplasty comparing 28 consecutive iAssist and 28 conventional TKAs: A prospective study

BackgroundThe objective of this study was to assess limb and component alignment after total knee arthroplasty (TKA) on long leg X-rays and to compare the use of iAssist, an accelerometric based computer-assisted device (CAD), with conventional jigs.MethodsWe prospectively recruited 56 consecutive patients undergoing primary unilateral TKA by a single surgeon into this study. In the first 28 patients iAssist navigation system was utilized and in the following 28 conventional jigs were used. The groups were comparable with regard to age, sex distribution, body mass index and preoperative hip–knee–ankle (HKA) angle. Our aim was to restore neutral coronal alignment and a five degree tibial slope.ResultsThe mean postoperative mechanical axis was 179.4° in the CAD group and 180.1° in the conventional group (P = 0.187). There were five TKAs deviating more than three degrees from neutral (18.5%) in the conventional group and none in the CAD group (P = 0.051). The mean femoral mechanical-condyles-angle was significantly closer (P < 0.001) to our target of 90° in the conventional group but contained more outliers (P = 0.67). The sagittal tibial slope was closer (P = 0.047) to our target of 85° in CAD-navigated TKAs with fewer outliers (P < 0.0001). The Oxford Knee Score showed comparable (P = 0.271) and good clinical outcome in both groups. The mean operation time was significantly longer in the CAD group (P < 0.001).ConclusionsThis study shows that the use of iAssist accelerometric CAD facilitates comparable good leg alignment after TKA in the frontal plane and more accurate tibial slope with fewer outliers in the sagittal plane compared with a conventional technique. Our operation time was longer with CAD.     

Tunnel widening after ACL reconstruction with aperture screw fixation or all-inside reconstruction with suspensory cortical button fixation: Volumetric measurements on CT and MRI scans

Background

Tunnel widening after anterior cruciate ligament reconstruction (ACLR) is influenced by the surgical and fixation techniques used. Computed tomography (CT) is the most accurate image modality for assessing tunnel widening, but magnetic resonance imaging (MRI) might also be reliable for tunnel volume measurements. In the present study tunnel widening after ACLR using biodegradable interference screw fixation was compared with all-inside ACLR using button fixation, with tunnel volume changes being measured on CT and MRI scans.

A novel anteroposterior axis of the tibia for total knee arthroplasty: An upright weight-bearing computed tomography analysis

BackgroundThe traditional anteroposterior (AP) axis (i.e., Akagi’s line) has been widely used as the tibial component AP axis during total knee arthroplasty (TKA). However, this AP axis has been defined based on computed tomography (CT) in a non-weight-bearing supine position. In this study, AP axes of the tibial plateau from upright CT in weight-bearing and non-weight-bearing positions were determined and compared.MethodsThis study included 43 knees from 23 healthy volunteers. CT images were obtained in weight-bearing and non-weight-bearing standing positions using a 320-detector row upright CT scanner. The line perpendicular to surgical transepicondylar axis projected onto the tibia plateau was determined as the AP axis in upright weight-bearing and non-weight-bearing conditions. Angular differences between these two conditions were measured.ResultsThe upright weight-bearing AP axis was positioned in a mean of 7.4 ± 4.3° of internal rotation relative to the traditional AP axis. Distance between the traditional and upright weight-bearing AP axis was 2.9 ± 1.6 mm at the edge of the tibial plateau. The upright non-weight-bearing AP axis was positioned in a mean of 3.5 ± 4.1° of internal rotation relative to the traditional AP axis. Mean angular difference between weight-bearing and non-weight-bearing conditions was 3.9 ± 4.1°.ConclusionsThe upright weight-bearing AP axis was positioned in 7.4° of internal rotation relative to the traditional AP axis, showing one-seventh of the tibial tuberosity away from the medial border of the tibial tubercle, which represents a practical landmark for the tibial component AP axis during TKA.     

Surgical epicondylar axis is not orthogonal to the femoral mechanical knee axis in valgus knees with primary osteoarthritis: Three-dimensional analysis according to knee coronal alignment in 112 patients

BackgroundDuring total knee arthroplasty (TKA), most surgeons align the femoral component along the surgical epicondylar axis (SEA) considering it as orthogonal to the femoral mechanical axis. However, it is still unclear how SEA coronal alignment varies according to the native coronal knee alignment. The main goal of this study was to analyze the SEA orientation according to the native coronal knee morphotype.MethodsA total of 112 patients underwent a three-dimensional (3D) -planning-based TKA. The SEA was then determined by locating the epicondyles on 3D models. The 3D femoral and tibial mechanical axes were marked and the femoral (FMA) and tibial (TMA) mechanical angles were measured. The native HKA angle was measured as FMA + TMA. The SEA orientation angles were measured in the coronal (SEA-α) and axial (SEA-β) plane. SEA orientation was compared between the valgus, neutral, and varus knees.ResultsThe mean SEA-α angle was 90.2 ± 3° and the mean axial SEA-β angle was 92.2 ± 1.3°. The SEA-α angle was significantly higher in the valgus group compared with the neutral group (92.3 ± 2.9°, 90 ± 2.9°, P = 0.0009) whereas there was no significant difference in the SEA-α angle between the varus and the neutral group (89.7 ± 2.3°, 90 ± 2.9°, P = 0.32).ConclusionsIn contrast to the neutral and varus knees, the SEA was not orthogonal to the femoral mechanical axis in patients undergoing TKA for primary osteoarthritis. Our results suggest adapting the coronal alignment of the femoral component during TKA, while maintaining an average 2° valgus in valgus knees. By contrast, with varus and neutral knees, our data support the use of a mechanical alignment.     

Comparative outcomes of patient-specific instrumentation,the conventional method and navigation assistance in open-wedge high tibial osteotomy: A prospective comparative study with a two-year follow up

BackgroundTo compare and analyze the correction precision, clinical outcomes and complications among the three methods of performing open-wedge high tibial osteotomy (HTO), including patient-specific instrumentation (PSI), conventional method and navigation assistance.MethodsIn this prospective, single-center study, we randomly assigned patients with knee osteoarthritis in a 1:1:1 ratio to undergo Open-wedge high tibial osteotomy (OWHTO) with conventional method, navigation assistance or PSI. The primary outcome was the target/observed hip–knee–ankle (HKA) angle difference at 1 month postoperatively. Secondary outcomes were changes in the postoperative posterior tibial slope (PTS) at 1 month and clinical outcomes including knee pain on a visual analogue scale (ranging from 0 to 100, with higher scores indicating more severe pain), Lysholm and Western Ontario and McMaster Universities Osteoarthritis Index (ranging from 0 to 240) scores at 1 month, 6 months, 12 months, and 24 months.ResultsFrom 2017 through 2019, a total of 608 patients were screened; of those patients, 144 were enrolled, with 48 in each group. The primary outcome of the HKA difference was 2.6 ± 2.0° in the conventional group, 2.3 ± 1.5° in the navigation group and 0.6 ± 1.0° in the PSI group (P < 0.001). Secondary outcomes including changes in the postoperative PTS and clinical outcomes at 1 month, 6 months, and 12 months were in the same direction as the primary outcome. There were no significant differences in the complications among the three groups.ConclusionsIn the present study, none of the three methods showed superiority in objective correction precision and clinical outcomes at 2 years.     

Effect of bone density and cement morphology on biomechanical stability of tibial unicompartmental knee arthroplasty

BackgroundUnicompartmental knee arthroplasty (UKA) offers good long-term survivorship and superior kinematics and function compared with total knee arthroplasty (TKA). However, revision rates are higher with aseptic loosening representing a major cause. Biomechanical stability depends on cement penetration. The goal of this study was to analyze the influence of cement morphology and bone density on primary stability of tibial UKA under physiological loading conditions in human tibiae.MethodsThirty-six tibial trays were implanted in fresh-frozen human cadaver knees and tested for primary stability using dynamic compression–shear testing. Prior to implantation, bone density had been quantified for all 18 tibiae. Postoperatively, cement penetration has been assessed on frontal cuts based on eight predefined parameters. The influence of bone density and cement morphology on biomechanical stability was determined using correlation and linear regression analysis.ResultsMean failure load was 2691 ± 832.9 N, mean total cement thickness was 2.04 ± 0.37 mm, mean cement penetration was 1.54 ± 0.33 mm and mean trabecular bone mineral density (BMD) was 107.1 ± 29.3 mg/ml. There was no significant correlation between failure load and cement morphology (P > .05). Failure load was significantly positive correlated with trabecular BMD (r = 0.843; P < .0001) and cortical BMD (r = 0.432; P = .0136).ConclusionsSimulating physiological loading conditions, the failure load of tibial UKA is linearly dependent on the trabecular BMD. The observed parameters of cementation morphology seem capable of preventing failure at the bone–cement interface before inherent bone stability is reached. Further research is required to assess the usefulness of a preoperative assessment of bone quality for patient selection in UKA.     

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

BackgroundThe anterolateral complex has been demonstrated to assist with rotational stability and prevention of anterior tibial translation during the pivot shift. In this study the Segond fracture is used as a surrogate for an anterolateral complex injury to determine if there is an association between Segond fracture and increased posterior tibial slope.MethodsPatients’ charts and radiographs were analyzed retrospectively for the presence of Segond fractures on injury radiographs. These patients, the Segond cohort, were then age and gender matched to a control cohort. Demographic as well MRI measurements of medial and lateral posterior tibial slope and lateral-to-medial slope asymmetry were collected for each cohort. Secondary outcome of anterior cruciate ligament reconstruction failure data was also collected.ResultsThe Segond group demonstrated a statistically significantly greater lateral posterior tibial slope (8.42° versus 6.55°, P = 0.003) as well as medial posterior tibial slope (6.57° versus 5.34° degrees, P = 0.045). There was no significant differences between lateral-to-medial asymmetry (2.18°versus 1.83°, P = 0.246).ConclusionPatients with Segond fractures at the time of anterior cruciate ligament injury have increased medial and lateral posterior tibial slope. This may relate to increased rotational and translational instability associated with anterolateral complex injuries. Surgeons treating these patient may use this information to counsel their patients on the risks of associated pathology at the time of arthroscopy such as lateral meniscal posterior root tears.     

In vivo evaluation of femoral and tibial graft tunnel placement following all-inside arthroscopic tibial inlay reconstruction of the posterior cruciate ligament

BackgroundThe arthroscopic all-inside tibial inlay technique represents a novel procedure for posterior cruciate ligament (PCL) reconstruction. However, in vivo investigations that evaluate the accuracy of this technique regarding anatomic graft tunnel placement are few. The objective of this study was to analyse the femoral and tibial tunnel apertures using computed tomography (CT) and compare these findings to recommendations in the literature.MethodsCT scans were obtained in 45 patients following single-bundle PCL reconstruction. The centres of the tibial and femoral tunnel apertures were correlated to measurement grid systems used as a radiographic reference.ResultsThe centre of the femoral tunnel aperture was located at 42.9% ± 9.4% of the total intercondylar depth and at 12.9% ± 7.2% of the total intercondylar height. The angle α for the femoral tunnel position was measured at 64.2° ± 10.0°. The centre of the tibial tunnel aperture was found at 51.8% ± 4.1% of the total mediolateral diameter of the tibial plateau. The superoinferior distance of the tibial tunnel aperture to the joint line was 9.6 mm ± 4.4 mm on frontal and 9.3 mm ± 3.4 mm on sagittal 3D-CT scans. The distance of the tibial tunnel aperture to the former physis line averaged to 0.8 mm ± 3.4 mm. Comparison to the corresponding reference values revealed no statistically significant difference.ConclusionArthroscopic tibial inlay reconstruction is an efficient procedure for precise replication of the anatomical footprint of the PCL.Level of evidenceIV, prospective case series     

A new technique for determining the rotational alignment of the tibial component during total knee arthroplasty

BackgroundWe evaluated the effectiveness of our new technique “Range of motion-anatomical (ROM-A) technique” which is the combination of the self-positioning technique “Range of motion (ROM) technique” and the anatomical landmarks technique in determining the tibial component (TC) rotation alignment in total knee arthroplasty (TKA) using a navigation system.MethodsThis retrospective study included 103 knees who underwent TKA. The ROM-A technique was consisted of two steps. First, the TC was set and marked by the ROM technique in knee extension. Second, the TC was set according to the marking in the knee flexion and the component rotational angle relative to the anatomical tibial anteroposterior (AP) axis was adjusted between 0° and 10° external rotation using the navigation system. The rotational angle of TC relative to the anatomical AP axis was measured using postoperative computed tomography. Moreover, the hypothetical rotational angle of the TC in the ROM technique was calculated only from the intraoperative difference between the two techniques.ResultsThe actual rotational angle by the ROM-A technique was externally rotated 3.0°, and the rotational outlier occurred in 3.0%. A significant difference in outlier rate was observed between the two techniques (p = 0.03). The hypothetical rotational angle of TC determined by the ROM technique (the first step only in the ROM-A technique) was externally rotated 4.6° and the TC rotational outlier (difference to AP axis: >10°) occurred in 11.7%.ConclusionUsing the ROM-A technique, the TC was finally fixed in almost all targeted rotational positions, and this technique could reduce the anatomical rotational outlier compared with the ROM technique.     

Failure rate analysis and clinical outcomes of two different femoral tunnel positions using anteromedial portal technique in anterior cruciate ligament reconstruction

AimTo analyze two different femoral tunnel positions and to evaluate their correlation with clinical, functional outcomes and surgical revision rate in patients who underwent primary arthroscopic anterior cruciate ligament (ACL) reconstruction with anteromedial (AM) portal technique.MethodsFrom January 2015 to October 2018, we recruited 244 patients that underwent primary single-bundle ACL reconstruction, using four strand-semitendinosus graft and AM portal technique for femoral tunnel placement. Patients were divided into two groups based on the different femoral tunnel positions: 117 patients of group A had ACL footprint center femoral tunnel position compared with 127 patients of group B, with femoral tunnel placement close to the AM bundle footprint. Preoperatively and at last follow up, all patients were assessed subjectively by Lysholm, Tegner, and International Knee Documentation Committee (IKDC) scores, while Lachman, Pivot-shift, and KT-1000 tests were performed to evaluate knee joint stability.ResultsGroup B patients showed significantly better results in Lysholm, objective, and subjective IKDC scores compared with patients of group A (P < 0.001). A significantly higher surgical failure rate was found in group A than in group B (10.26% vs. 2.3%; P < 0.001). A higher anterior knee laxity was recorded in patients of group A than in patients of group B (1.9 ± 1.1 vs. 1.3 ± 1 mm; P < 0.001); a reduction in mean anterior tibial translation from preoperative to final follow up was found in group B compared with group A (3.5 ± 1.2 vs. 2.7 ± 1.1 mm; P < 0.001). No significant differences in the Tegner scale were found between the two groups.ConclusionACL reconstruction performed using the AM portal technique showed better and more satisfactory clinical and functional outcomes associated with a lower failure rate when the femoral tunnel had been placed more eccentrically in the footprint, in the AM bundle center position.