Yong Seuk Lee

Clinical, Functional, and Morphological Evaluations of Posterior Cruciate Ligament Reconstruction With Remnant Preservation Minimum 2-Year Follow-up

Background: Numerous posterior cruciate ligament (PCL) reconstruction techniques have evolved and have revealed satisfactory outcomes; however, the optimal operative method for PCL reconstruction remains controversial. Hypothesis: Transtibial PCL reconstruction with a remnant preservation technique would result in successful clinical, radiological, functional, and morphological outcomes. In addition, it was hypothesized that the results of combined PCL and posterolateral corner (PLC) reconstruction would be comparable with those of isolated PCL reconstruction. Study Design: Case series; Level of evidence, 4. Methods: A total of 168 patients who underwent arthroscopic PCL reconstruction with or without reconstruction of the PLC between March 2006 and June 2011 were retrospectively reviewed. Ninety-two patients who met the inclusion criteria were enrolled, and 47 of 92 patients who underwent combined PCL and PLC reconstruction were evaluated as a subgroup. The PLC was reconstructed using the single fibular sling method. The patients were assessed by means of the Lysholm score, International Knee Documentation Committee (IKDC) subjective knee score, and Tegner activity score. Stability was evaluated using a KT-2000 arthrometer and Telos device. Proprioception was assessed using the Biodex System. Follow-up magnetic resonance imaging (MRI) was performed in 34 patients, and second-look arthroscopic surgery was conducted in 36 patients. Results: The minimum follow-up duration was 24 months in all patients. Clinical outcomes and posterior instability improved significantly. The mean Lysholm score improved from 56.7 ± 7.1 to 89.3 ± 7.3, the mean IKDC subjective knee score improved from 53.3 ± 9.6 to 86.2 ± 6.1, and the mean Tegner activity score was 2.5 ± 0.8 preoperatively and 5.1 ± 1.3 postoperatively (all P < .001). The mean side-to-side difference on posterior stress radiography with the Telos device improved significantly, decreasing from 12.1 ± 2.5 mm to 2.7 ± 1.3 mm (P < .001). The mean side-to-side difference on varus stress radiography was reduced from 5.9 ± 0.8 mm preoperatively to 1.3 ± 1.0 mm after combined PCL and PLC reconstruction (P < .001). Postoperative proprioception recovered to a level similar to that of the uninvolved side, and MRI and second-look arthroscopic surgery showed a high rate of complete healing and synovialization in patients who underwent either isolated PCL reconstruction or combined PLC and PCL reconstruction. Conclusion: Transtibial PCL reconstruction with remnant preservation resulted in satisfactory clinical, functional, radiological, and morphological outcomes. The results of combined posterolateral rotatory instability were comparable with those for isolated PCL reconstruction with adequate PLC reconstruction.

Effect of Anticipation on Lower Extremity Biomechanics During Side- and Cross-Cutting Maneuvers in Young Soccer Players

Background: Less mature athletes exhibit biomechanical parameters during cutting maneuvers that may place these athletes at greater risk for injury than their more mature counterparts, especially if the maneuvers are unanticipated. However, most studies on risk factors for anterior cruciate ligament (ACL) injury have focused on neuromuscular and knee kinematic differences between the sexes, not on the biomechanical parameters between specific sporting maneuvers. Hypotheses: (1) Anticipation will have a greater effect than the type of cutting maneuver (side- vs cross-cutting) in terms of the biomechanical risk factors for ACL injuries, and (2) the biomechanical risk factors will be different between the 2 types of maneuvers. Study Design: Controlled laboratory study. Methods: Thirty-seven young, male middle school soccer players participated in this study. Three-dimensional motion analysis featuring ground-reaction force and electromyography of the right leg was used. Kinematics, kinetics, and electromyography data for each athlete were analyzed during anticipated and unanticipated side- and cross-cutting maneuvers. The differences between anticipated and unanticipated states as well as between side- and cross-cutting maneuvers were calculated and compared. Results: After unanticipated side-cutting, the time to peak ground-reaction force was longer and peak values were smaller compared with anticipated side-cutting. Flexion, valgus, and internal rotations in the knee joint were larger, and greater flexion and valgus moments were observed. The vastus lateralis and vastus medialis showed lower activity, and the lateral gastrocnemius showed higher activity after unanticipated side-cutting maneuvers. With unanticipated cross-cutting, the time to peak ground-reaction force was longer and peak values were smaller compared with anticipated cross-cutting, and the lateral gastrocnemius showed higher activity. Differences in the peak values of the mediolateral and vertical forces were smaller in the cross-cutting maneuver than in side-cutting. Changes in flexion and adduction of the hip joint, flexion of the knee joint, and inversion of the ankle joint were larger during side-cutting. Conclusion: Although there were some interactions between direction and anticipation, anticipating a cutting maneuver generally had a greater effect than the type of maneuver when there was no significant interaction. Clinical Relevance: Increases in the valgus angle and moment of the knee joint and higher lateral gastrocnemius activity during the late period showed an association with ACL injury risk factors during side-cutting, and higher lateral gastrocnemius activity during the early period showed an association with injury risk factors during cross-cutting.

Does surgical reconstruction produce better stability than conservative treatment in the isolated PCL injuries

IntroductionThe purpose of this study was to conduct a systematic review to address the stability outcome from reconstruction and conservative treatments.Materials and methodsInclusion criteria were as follows: (1) English language, (2) human subject, (3) measures of stability outcomes, and (4) patients with isolated PCL injuries. We did not limit the type of study design (interventional or non-interventional study) and included all published systematic reviews. The following data were extracted: the number of study populations, year of publication, baseline characteristics of patients, follow-up period, and outcome data. The primary outcome variable was side-to-side difference (STSD).ResultsIn the conservative treatment, the average STSD ranged from 3.5 to 5.3xa0mm on Telos™ (range 0.7–12.0xa0mm) and from 3.0 to 5.2xa0mm on KT-1000™ (range 0.5–10xa0mm). Among reconstructive treatment, the average STSD ranged from 2.0 to 3.7xa0mm on Telos™ (range 0–7xa0mm) and 0.7–5.9xa0mm on KT-1000™ (range −1 to 11.8xa0mm). In the conservative treatment, the estimated weighted mean STSD difference was 3.49 [95xa0% confidence interval (CI): 0.95–6.03] on Telos™ and 2.64 (95xa0% CI 0.76–4.51) on KT-1000™. On the other hand, in the reconstructive treatment, the estimated mean STSD difference was 8.09 (95xa0% CI 7.11–9.07) on Telos™ and 8.45 (95xa0% CI 6.44–10.47) on KT-1000™.ConclusionsThis systematic review noted more satisfactory and consistent stability in the reconstructive treatment group. However, more complications and small differences of stability between groups should be also considered.

Comparison of transtibial and retrograde outside-in techniques of anterior cruciate ligament reconstruction in terms of graft nature and clinical outcomes: a case control study using 3T MRI

IntroductionThis study was performed to compare ACL graft maturation and morphologies using MRI between trans-tibial (TT) and retrograde outside-in (OI) techniques, and to compare clinical outcomes between the two groups.Materials and methodsPatients underwent single-tunnel ACL reconstruction using quadrupled hamstring autografts, with the TT technique used on 42 patients (TT group) and the retrograde OI technique used on 39 patients (OI group). All patients were examined with 3xa0T MRI at 6xa0months (between 5 and 7xa0months) after surgery. The signal intensity of the reconstructed graft was analyzed and compared between the two groups, using the signal/noise quotient (SNQ), the orientation of the ACL graft and the tibial tunnel location of the graft. The SNQ value is indicative of graft maturation, and the orientation of the graft and the tibial tunnel location of the graft represent graft morphology. Clinical evaluation was performed before the surgery and 2xa0years or more after the surgery.ResultsThe mean SNQ value of the TT group was significantly (Pxa0=xa00.030) lower than that of the OI group. The mean sagittal ACL angle (Pxa0<xa00.001) and the mean coronal ACL angle (Pxa0<xa00.001) were more vertical in the TT group. The tibial tunnel aperture was located at a significantly (Pxa0<xa00.001) more posterior position in the TT group. There was no statistically significant difference in the clinical results between the two groups.ConclusionsThe OI technique showed a more anteriorly positioned tibial tunnel and a more oblique graft orientation in both sagittal and coronal planes. However, in comparison with the TT group, a significantly higher SNQ value was noticed in the follow-up MRI of the OI group at 6xa0months, although clinical results of the two groups were not significantly different during at least the 2-year follow-up.

Accuracy and Reproducibility of the Femoral Tunnel With Different Viewing Techniques in the ACL Reconstruction

The purpose of this study was to compare the accuracy and reproducibility of the femoral tunnel location among 3 different viewing techniques used during outside-in anterior cruciate ligament (ACL) reconstruction with 3- dimensional (3-D) computed tomography (CT): (1) an anterolateral (AL) or anteromedial (AM) portal with a 30° arthroscope (A group) vs (2) a posterolateral (PL) portal with a 70° arthroscope (PL group) vs (3) a trans-septal (TS) portal with a 30° arthroscope (TS group). A total of 106 patients undergoing outside-in ACL reconstruction were recruited. Patients were divided into 3 groups according to viewing technique (A group=36 patients; PL group=35 patients; TS group=35 patients). Femoral tunnel locations were evaluated with the quadrant method and the anatomic coordinate axes measurement (ACAM) method in the medial wall of the lateral femoral condyle using 3-D reconstructed CT. The accuracy and reproducibility of the femoral tunnel locations were compared among the 3 techniques. The accuracy of the tunnel location was higher in the TS group by the quadrant method as well as the ACAM method. The reproducibility of the femoral tunnel position in the TS group was the highest, and the femoral tunnel locations of the TS group were more compactly distributed compared with those of the A and PL groups. The accuracy and reproducibility of the femoral tunnel location could be improved with a TS portal viewed using a 30° arthroscope. Anteromedial/anterolateral and PL portals viewed using a 70° arthroscope showed no difference. [Orthopedics. 2016; 39(6):e1085-e1091.].

Evaluation of the interaction between contact force and decision making on lower extremity biomechanics during a side-cutting maneuver

IntroductionThe purposes of this study were (1) to compare the effect between contact force [first and second ground reaction force (GRF)] and decision making (anticipation vs unanticipation) on lower extremity biomechanics during a side-cutting maneuver in young soccer players; and (2) to identify which condition is more vulnerable to biomechanical risk factors of the anterior cruciate ligament (ACL) injury.Materials and methodsSixteen young, male middle school soccer players with right leg dominance participated in this study. Three-dimensional motion analysis featuring GRF and electromyography (EMG) of the right leg was used during the stance phase of the side-cutting maneuver. Kinematics, kinetics, and EMG data for each athlete were analyzed and averaged for three successful anticipated and unanticipated side-cutting maneuvers.ResultsGRF was smaller and muscle activities were lower in most muscle groups in the first peak than that of the second peak. More flexion and internal rotational angles of the hip joint were observed in the unanticipated first peak that that of the second peak. Lesser flexion angle and moment of the knee joint observed in the first peak than that of the second peak, and abduction moment was increased after the unanticipation.ConclusionThe GRF and muscle activities were smaller in the first peak than those in the second peak; however, first peak showed a closer association with biomechanical risk factors of the ACL injury. There were some interactions between contact force and decision making and unanticipation made the first peak more risky to the ACL injury.

Role of an anatomically contoured plate and metal block for balanced stability between the implant and lateral hinge in open-wedge high-tibial osteotomy

IntroductionOpen-wedge high tibial osteotomy (OWHTO) is a well-established surgical option for medial compartment osteoarthritis of the varus knee. The initial strength of the fixation plate is critical for successful correction maintenance and healing of the osteotomy site. This study was conducted to verify if a newly designed anatomical plate (LCfit) improves the stability of both the medial implant and lateral hinge area, as well as to evaluate how the metal block contributes to both medial and lateral stability.Materials and methodsA finite element (FE) tibial model was combined with TomoFix plate, a LCfit plate with and without a metal block. Data analysis was conducted to evaluate the balanced stability, which refers to the enforced lateral stability resulting from redistribution of overall stress. We assessed the balanced stability of the medial implant and lateral hinge area in three cases using the same Sawbones and loads using the tibia FE model.ResultsThe LCfit plate reduced stress by 23.1% at the lateral hinge compared to the TomoFix plate (TomoFix vs. LCfit: 34.2u2009±u200923.3xa0MPa vs. 26.3u2009±u200917.5xa0MPa). The LCfit plate with a metal block reduced stress by 40.1% at the medial plate (210.1u2009±u200964.2xa0MPa vs. 125.8u2009±u200965.7xa0MPa) and by 31.2% (26.3u2009±u200917.5xa0MPa vs. 18.1u2009±u200912.1xa0MPa) at the lateral hinge area compared to the reduction using the LCfit plate without a metal block.ConclusionThe newly designed fixation system for OWHTO balanced the overall stress distribution and reduced stress at the lateral hinge area compared to that using a conventional fixation system. The addition of the metal block showed additional benefits for balanced stability between the medial implant and lateral hinge area. However, this conclusion could only be drawn using the FE model in this study. Therefore, further clinical studies are necessary to reveal the clinical effect of reduced lateral stress on the occurrence of the lateral hinge fracture and the biologic effect of the metal block on the healing of the medial cortex.

Graft sources do not affect to the outcome of transtibial posterior cruciate ligament reconstruction: a systematic review

IntroductionDespite numerous published reports on posterior cruciate ligament (PCL) reconstruction in the past 30 years, the ideal graft source remains unclear, and few objective scientific data have been published that thoroughly evaluate the long-term outcomes according to the graft source. We, therefore, conducted a systematic review of available high-quality comparative studies that evaluated clinical and objective stability testing to compare the different graft sources for PCL reconstruction.Materials and methodsEight articles were included in the final analysis. There were two level II and six level III studies. Autograft included 4-strand hamstring grafts (SHGs), 7-SHGs, quadriceps tendon, and patellar tendon. Allografts included Achilles tendon and tibialis anterior tendon. Hybrid graft and a ligament advanced reinforcement system (LARS) were used in one study each. Comparison was performed between autografts and allografts in three studies, between different autografts in two studies, between autograft and LARS in one study, among three different grafts in one study, and between 4 and 7-SHGs in one study.ResultsMost studies reported no statistically significant differences in the clinical results, except for one study that compared 4- and 7-SHG. Stability was similar or superior in a comparison between autografts and allografts, and was not statistically different between different autografts or between 4-SHG and LARS. However, more-stranded HG showed better stability than that of the less-stranded HG. Complications were more frequent with autografts.ConclusionUsing a comprehensive analysis of the current literature, the authors could not identify an individual graft source with clearly superior clinical results, compared with other graft sources. However, autografts, especially 4-SHGs, showed similar or superior stability to irradiated allografts. Therefore, the graft source has a minimal effect on the clinical outcome, but it could have some effects on stability in single bundle transtibial PCL reconstruction.