Hyuk-Soo Han

Changes in femoral posterior condylar offset and knee flexion after PCL-substituting total knee arthroplasty: comparison of anterior and posterior referencing systems

AbstractPurposenAnterior referencing and posterior referencing are two major techniques for positioning femoral components and balancing the sagittal plane during total knee arthroplasty (TKA). The purpose of this study was to evaluate the changes in medial and lateral posterior condylar offset (PCO) after bilateral TKA using anterior referencing (AR) or posterior referencing (PR) systems and compare the effect of the PCO changes on knee flexion.MethodsTwenty female patients (mean age, 68.6xa0years) underwent bilateral TKA using the AR technique in one knee and the PR technique in the contralateral knee. Three-dimensional reconstructed computed tomographic images from the sagittal plane were used to evaluate PCO before and after arthroplasty. Knee Society scores and range of motion were evaluated postoperatively at a mean of 2.9xa0years.ResultsPostoperative medial and lateral PCOs were significantly greater (pxa0<xa00.001 and pxa0=xa00.048, respectively) in the AR group (30.9xa0±xa02.2 and 29.1xa0±xa01.5xa0mm, respectively) than those in the PR group (29.1xa0±xa02.7 and 27.3xa0±xa02.3xa0mm, respectively). In addition, the degree of change in the PCO after TKA was greater in the AR group than in the PR group. On the final follow-up, no differences in the degree of knee flexion were observed between the two groups (124.7° for AR and 124.5° for PR). Knee Society scores were similar in the two groups both preoperatively and postoperatively. On the final follow-up, individual changes in the medial and lateral PCO were not associated with changes in the knee flexion angle.ConclusionsRestoration of PCO after TKA was more accurate with the PR technique than with the AR technique. However, the postoperative differences in PCO showed no correlation with changes in knee flexion 2xa0years after PCL-substituting TKA.Level of evidenceTherapeutic study, Level I.

Proximal tibial anterior open-wedge oblique osteotomy: A novel technique to correct genu recurvatum

BACKGROUNDnFor successful acute correction of genu recurvatum, accurate correction of plateau angle, restoration of anatomical axis, rigid fixation, and preservation of patellar height are essential. However, a surgical treatment that satisfies all these conditions has not yet been established. The purpose of this study was to evaluate the novel technique of proximal tibial anterior open-wedge oblique osteotomy (PT-AOWOO) for the treatment of genu recurvatum.nnnMETHODSnFive patients with genu recurvatum underwent PT-AOWOO from 2008 to 2013. The open-wedge center of rotation of angulation (CORA) was determined by the intersection of transverse bisector line and tibial posterior cortex to prevent secondary translational deformity. An osteotomy was performed from the distal margin of the tibial tuberosity to the planned CORA to maintain patellar height and provide sufficient space for fixation. The opening gap was calculated by the picture-archiving and communications system (PACS)-Photoshop method.nnnRESULTSnThe mean angle of recurvatum was 17° (range, 14 to 25°) preoperatively and -0.4° (range, -5° to 5°) postoperatively. The mean angle of the tibial plateau was 79.8° (range, 67 to 85°) preoperatively and 98.4° (range, 95 to 105°) postoperatively. Tibial anatomical axis was restored and the patellar height was maintained in all patients. The overall results were excellent in three patients and good in two patients.nnnCONCLUSIONSnThe PT-AOWOO and its unique osteotomy level corrected the tibial plateau angle accurately, restored the sagittal tibial axis without translation, maintained patellar height, and enabled rigid fixation. This technique showed satisfactory radiologic and clinical outcomes without any complications.

Anthropometric difference of the knee on MRI according to gender and age groups

The purpose of this study was to analyze the anthropometric data from MRI images that were obtained from the non-arthritic knees in Asian adults, and to identify the existence of morphologic differences between age groups. This cross-sectional study included knee MR images of 535 patients (273 males, 262 females) taken for the evaluation of soft-tissue injuries, excluding cases with cartilage defect and malalignment. The age, gender, height, and BMI were also assessed. The patients were grouped into three different 20-year age groups (20–39, 40–59, and 60–79). The MRI analysis was performed on the anthropometric parameters of distal femur and posterior tibial slope. Age-related differences were found in femoral width, distance from the distal and posterior cartilage surface to the medial/lateral epicondyle, medial posterior condylar offset (PCO), and posterior condylar angle (PCA) (all Pxa0<xa00.001), but not in lateral PCO, and medial/lateral tibial slopes. In the analysis of covariance analyses, significant interaction between gender and age groups was found in most parameters, but not in PCA, distance from the posterior cartilage surface to the medial epicondyle, or medial tibial slope. We found anthropometric differences among age groups exist in most of distal femoral parameters, but not in posterior tibial slope. The results of this study can be used by manufacturers to modify prostheses to be suitable for the future Asian elderly population.

Large meniscus extrusion ratio is a poor prognostic factor of conservative treatment for medial meniscus posterior root tear

PurposeThe purpose of this study was to find a prognostic factor of medial meniscus posterior root tear (MMPRT) for surgical decision making.MethodsEighty-eight patients who were diagnosed as acute or subacute MMPRT without severe degeneration of the meniscus were treated conservatively for 3 months. Fifty-seven patients with MMPRT showed good response to conservative treatment (group 1), while the remaining 31 patients who failed to conservative treatment (group 2) received arthroscopic meniscus repair. Their demographic characteristics and radiographic features including hip-knee-ankle angle, joint line convergence angle, Kellgren–Lawrence grade in plain radiographs, meniscus extrusion (ME) ratio (ME-medial femoral condyle ratio, ME-medial tibial plateau ratio, ME-meniscus width ratio), the location of bony edema, and cartilage lesions in MRI were compared. Receiver operating characteristic (ROC) curve analysis was also performed to determine the cut-off values of risk factors.ResultsThe degree of ME-medial femoral condyle and medial tibia plateau ratio of group 2 was significantly higher than group 1 (0.08 and 0.07 vs. 0.1 and 0.09, respectively, both pu2009<u20090.001). No significant (n.s.) difference in other variables was found between the two groups. On ROC curve analysis, ME-medial femoral condyle ratio was confirmed as the most reliable prognostic factor of conservative treatment for MMPRT (area under ROCu2009=u20090.8).ConclusionThe large meniscus extrusion ratio was the most reliable poor prognostic factor of conservative treatment for MMPRT. Therefore, for MMPRT patients with large meniscus extrusion, early surgical repair could be considered as the primary treatment option.Level of evidenceIII.

Anterior cruciate ligament reconstruction with quadriceps tendon-patellar bone allograft: matched case control study

BackgroundQuadriceps tendon-patellar bone (QTPB) autograft is an excellent graft option with good clinical outcome. Use of QTPB autografts have increased because they minimize donor-site morbidity including anterior knee pain, while providing adequate mechanical strength. Although, there were many clinical results about allografts that used in anterior cruciate ligament (ACL) reconstruction, it have never been reported about the clinical outcome of ACL reconstruction with QTPB allograft.The purpose of this study is to evaluate the clinical outcome of ACL reconstruction with QTPB allograft and to compare with QTPB autograft. We hypothesized that ACL reconstruction with QTPB allograft had good functional outcomes and stability and no significant difference compared to the ACL reconstruction with QTPB autograft.MethodsFrom February 2009 to January 2014, 213 cases who received ACL reconstruction with QTPB grafts were included. Forty-five patients who received ACL reconstruction with QTPB allograft were individually matched in age, sex, direction of the injured knee and body mass index (BMI) to a control group of 45 patients who received QTPB autograft. Clinical results were evaluated using International Knee Documentation Committee (IKDC) score, Lysholm score, Tegner scale, Knee injury and Osteoarthritis Outcome Score (KOOS) and ligament laxity. An average follow-up time was 31.2xa0months.ResultsThe functional scores and ligament laxity improved from initial to the last visit in those with ACL reconstruction with QTPB allograft (pu2009<u20090.05). No significant statistical difference was found in clinical outcomes and complications including re-rupture between the QTPB allograft and autograft groups (pu2009>u20090.05). Laxity using anterior drawer test, Lachman test and KT-2000 showed no significant difference. No significant difference was found between the two groups in quadriceps peak extension torque, except at 60° per second at 6xa0months.ConclusionQTPB allograft achieved good clinical outcome with no difference compared with QTPB autograft. QTPB allograft for ACL reconstruction is promising alternative to selected and compliant patients. Long-term follow-up needs to further evaluate the clinical outcomes and complications including re-rupture rate.

Efficacy and safety of a new elastic tourniquet cuff in total knee arthroplasty: a prospective randomized controlled study

BackgroundThe effects of cuff shape, timing of tourniquet application, and automated systems using limb occlusion pressure (LOP) have been reported to minimize the appropriate tourniquet pressure. However, studies on the raw material of the cuff itself to reduce the complicationsxa0related to the tourniquet have been very rarely reported. The purpose of this study is to report the efficacy and safety of a tourniquet system with a new elastic cuff in which pressure is set with LOP in total knee arthroplasty (TKA).MethodsA total of 63 patients who underwent primary TKA for osteoarthritis were enrolled from July to December 2015. Thirty-one patients were allocated to the new elastic cuff group and 32 in the conventional cuff group. Bloodless surgical field, pain visual analog scale (VAS) on the thigh, thigh circumference, range of motion, incidence of deep vein thrombosis, and muscle enzyme level after surgery were checked and compared between the 2 groups.ResultsOnly 1 of the 31 patients in the elastic cuff group required more pressure for obtaining a bloodless surgical field, whereas 4 of the 32 patients in the conventional cuff group required more pressure to complete surgery without being disturbed by sustained bleeding. Two patients in the conventional cuff group needed treatment for blisters and bullae at the tourniquet application site. There was no difference in pain VAS score, thigh circumference, range of motion, incidence of deep vein thrombosis, and level of muscle enzyme.ConclusionsA new elastic tourniquet cuff provided a more proper bloodless surgical field with less adjustment of tourniquet pressure despite a similar level of tourniquet pressure compared to the conventional cuff and had a low incidence of skin complications on the site of tourniquet application in TKA. These benefits make it an effective and safe medical device for orthopedic surgery requiring a tourniquet, such as TKA.

Successful anterior cruciate ligament reconstruction and meniscal repair in osteogenesis imperfecta

A case of anterior cruciate ligament (ACL) reconstruction with meniscal repair in an osteogenesis imperfecta patient is reported. A 24-year-old female with osteogenesis imperfecta type 1a suffered from a valgus extension injury resulting in tear of ACL and medial meniscus. She underwent an arthroscopic-assisted ACL reconstruction and medial meniscus repair. Meniscal tear at the menisco-capsular junction of the posterior horn of medial meniscus was repaired with three absorbable sutures via inside-out technique. ACL reconstruction was then performed with a bone-patellar tendon-bone allograft. The patient was followed up for 1xa0year with intact ACL grafts and healed medial meniscus. This case report showed that successful ACL reconstruction and meniscal repair is possible in an osteogenesis imperfecta patient.Level of evidence V.

Interactive effect of femoral posterior condylar offset and tibial posterior slope on knee flexion in posterior cruciate ligament-substituting total knee arthroplasty

BACKGROUNDnThis work aimed to evaluate the changes in the femoral posterior condylar offset (PCO) and tibial slope after posterior cruciate ligament (PCL)-substituting total knee arthroplasty (TKA), and to address the presence of any interactive effect between the two on knee flexion.nnnMETHODSnFifty-two PCL-substituting TKAs were performed using a posterior referencing system. Three-dimensional reconstructed computed tomographic (CT) images were used to evaluate PCO and tibial slope before and after arthroplasty. Range of motion and clinical scores were evaluated at a mean of 3.1years postoperatively. Multivariate linear model with interaction terms was used to evaluate and compare the relationships among changes in PCO, tibial slope, and postoperative knee flexion angles.nnnRESULTSnThe degree of change in PCO was greater in the lateral condyle than in the medial condyle (3.1±2.5mm and -0.5±2.8mm, respectively). Postoperative medial and lateral tibial slopes were 1.4°±1.8 and 1.4°±2.0, respectively. The mean degree of postoperative knee flexion was 125°. Analysis with interaction terms and covariate adjustment demonstrated that medial PCO and tibial slope were significantly related to knee flexion with interactive effect (P=0.011). In cases with <3° posterior tibial slope, the postoperative PCO was positively correlated to the degree of knee flexion angle. However, in cases with >3° tibial slope, PCO was negatively correlated to knee flexion.nnnCONCLUSIONnMedial femoral PCO and tibial slope showed interactive effect on knee flexion after PCL-substituting TKAs. Reconstitution of the proper PCO and avoiding excessive tibial slope may be necessary.

Baseline varus deformity is associated with increased joint loading and pain of non-operated knee two years after unilateral total knee arthroplasty

BACKGROUNDnThe goals of this study were (1) to document the gait pattern of patients with unilateral knee osteoarthritis (OA), (2) to determine the knee adduction moment (KAM) changes in the non-operated knee, and (3) to identify the predictors of change in KAM in the non-operated knee.nnnMETHODSnThe study recruited 23 patients with advanced unilateral knee OA. The preoperative Kellgren-Lawrence (KL) grade of the non-operated knee was one or two; non-operated knee pain, rated using a numeric rating scale (NRS), was less than three out of 10 points. We used a commercial gait analysis system to evaluate kinetics and kinematics. Radiological and gait measurements at the two-year follow-up were compared with baseline data.nnnRESULTSnThe preoperative asymmetrical gait cycle characterized by elongation of the stance phase of the non-operated knee became symmetrical after TKA. The average KAM of the non-operated knee increased (P=0.010) and it was best predicted by the baseline mechanical axis of the non-operated knee. If the baseline mechanical axis was varus four degrees or above (varus group), the average KAM increased by 0.64 (% body weight×height, P=0.015), while for varus less than four degrees (non-varus group), KAM was unchanged. The KL grade was increased in the varus group (P=0.020) but it was unchanged in the non-varus group. Average pain NRS score was also higher (P=0.044) in the varus group.nnnCONCLUSIONSnClose follow-up is necessary for patients with a baseline varus deformity of the non-operated knee because of the higher possibility of developing pain, subsequent arthritis and increased joint loading of the non-operated knee.nnnLEVEL OF EVIDENCEnIII, retrospective cohort study.

Cementing technique affects the rate of femoral component loosening after high flexion total knee arthroplasty

BACKGROUNDnThe purpose of this study was to determine the effects of different cementing techniques on the rate of early femoral loosening of high-flexion total knee arthroplasties (TKAs).nnnMETHODSnA total of 734 knees from 486 patients treated with high-flexion design TKA between July 2001 and July 2010 were divided into two groups based on the cementing technique used. For 403 knees (group N), cement was applied onto the distal and anterior cut surfaces of the femur and the posterior flanges of the femoral component without pressurization. For 331 knees (group P), cement was applied onto distal and anterior femoral cut surfaces with digital pressurization and whole cement surfaces of the femoral component. Two groups were subjected to clinical and radiological evaluation with a minimum five year follow-up period. Cox proportional hazards model with revision surgery of the prosthesis or radiological loosening as an endpoint was used to evaluate the effect of the cementing technique and other covariates.nnnRESULTSnThe pressurizing and bi-surface cementing technique resulted in significant reduction in femoral radiological loosening incidence compared to that without pressurization (0.3% vs. 2.5%, P=0.015) and revision rate for aseptic causes (0.9% vs. 3.2%, P=0.032). Cox proportional hazard regression analysis revealed a significant difference in component survival rate between the two groups if femoral radiological loosening was considered as failure (hazard ratio, 4.229, 95% confidence interval (CI): 1.256-14.243, P=0.020).nnnCONCLUSIONnPressurizing and bi-surface cementation can reduce the occurrence rate of early loosening around the femoral component in high-flexion TKAs.