Differences in Resumption of Orthopedic Surgery According to Characteristics of Surgery during COVID-19 Pandemic: National Registry Data

Background@#Healthcare services have been restricted after the coronavirus disease 2019 (COVID-19) outbreak. With the pandemic still ongoing, the patterns of orthopedic surgery might have changed. The purpose of this study was to determine whether the reduced volumes of orthopedic surgery were recovered over time. Among the trauma and elective surgery, which accounted for most orthopedic surgical procedures, we also sought to elucidate whether the changes in the volumes of orthopedic surgery differed according to the type of surgery. @*Methods@#The volumes of orthopedic surgery were analyzed using the Health Insurance Review and Assessment Service of Korea databases. The surgical procedure codes were categorized depending on the characteristics of the procedures. The actual volumes of surgery were compared with the expected volumes to elucidate the effect of COVID-19 on surgical volumes. The expected volumes of surgery were estimated using Poisson regression models. @*Results@#The reducing effect of COVID-19 on the volumes of orthopedic surgery weakened as COVID-19 continued. Although the total volumes of orthopedic surgery decreased by 8.5%–10.1% in the first wave, those recovered to a 2.2%–2.8% decrease from the expected volumes during the second and third waves. Among the trauma and elective surgery, open reduction and internal fixation and cruciate ligament reconstruction decreased as COVID-19 continued, while total knee arthroplasty recovered. However, the volumes of hemiarthroplasty of the hip did not decrease through the year. @*Conclusions@#The number of orthopedic surgeries, which had decreased due to COVID-19, tended to recover over time, although the pandemic was still ongoing. However, the degree of resumption differed according to the characteristics of surgery. The findings of our study will be helpful to estimate the burden of orthopedic surgery in the era of persistent COVID-19.

Effect of Total Hip Arthroplasty on Ipsilateral Lower Limb Alignment and Knee Joint Space Width: Minimum 5-Year Follow-up

Background@#This study aimed to 1) assess the effect of total hip arthroplasty (THA) on coronal limb alignment, namely, the hip–knee–ankle angle (HKA), 2) identify factors that determine changes in the HKA, and 3) determine whether alignment changes influence the knee joint space width. @*Methods@#We retrospectively evaluated 266 limbs of patients who underwent THA. Three types of prostheses with neck shaft angles (NSAs) of 132°, 135°, and 138° were used. Several radiographic parameters were measured in the preoperative and final radiographs (at least 5 years after THA). A paired t-test was used to confirm the effect of THA on HKA change.Multiple regression analysis was performed to identify radiographic parameters related to HKA changes following THA and changes in knee joint space width. Subgroup analyses were performed to reveal the effect of NSA change on the HKA change, and the proportion of total knee arthroplasty usage and changes in radiographic parameters between maintained joint space and narrowed joint space groups were compared. @*Results@#The preoperative mean HKA was 1.4° varus and increased to 2.7° varus after THA.This change was related to changes in the NSA, lateral distal femoral angle, and femoral bowing angle. In particular, in the group with a decrease in NSA of > 5°, the preoperative mean HKA was largely changed from 1.4° varus to 4.6° varus after THA. The prostheses with NSA of 132° and 135° also led to greater varus HKA changes than those with an NSA of 138°. Narrowing of the medial knee joint space was related to changes in the varus direction of the HKA, decrease in NSA, increase in femoral offset. @*Conclusion@#A large reduction in NSA can lead to considerable varus limb alignment after THA, which can have adverse effects on the medial compartment of the ipsilateral knee.

Comparative Analysis of T-Score Discordance between a Registry-Based Korean Population and Atypical Femoral Fracture Patients of a Single Institution

Background@#The purpose of this study was to analyze the epidemiology of T-score discordance between the spine and femur in the South Korean population and compare the prevalence of T-score discordance between the Korean osteoporosis population and atypical femoral fracture (AFF) patients. @*Methods@#A total of 12,422 subjects from the Korea National Health and Nutrition Examination Survey were reviewed retrospectively. T-score discordance was defined as a difference of ≥ 1 standard deviation between the lumbar spine (LS) and femoral neck (FN) bone mineral density (BMD). The prevalence of T-score discordance (low LS [LS BMD FN BMD], and total [low LS + low FN]) was investigated in the osteoporosis and non-osteoporosis groups and stratified by sex and age. Tscore discordance of 63 patients with AFFs diagnosed at a single institution was compared with that of the Korean osteoporosis population using propensity score matching. @*Results@#T-score discordance was prevalent in the Korean osteoporosis population (44.8%), and low LS discordance (37.5%) was more frequently seen than low FN discordance (7.2%) (p < 0.001). The prevalence of total and low LS discordance was significantly higher in AFF patients than in the Korean osteoporosis population (total discordance: 69.8% and 42.5%, respectively; low LS discordance: 63.5% and 31.7%, respectively; p < 0.001). @*Conclusions@#T-score discordance was highly prevalent in the Korean osteoporosis population, and low LS discordance was more common than low FN discordance. Nevertheless, the prevalence of low LS discordance was significantly higher in AFF patients than in the Korean osteoporosis population.

Posterior condylar offset changes and its effect on clinical outcomes after posteriorsubstituting, fixed-bearing total knee arthroplasty: anterior versus posterior referencing

Background@#We sought to determine whether there was a difference in the posterior condylar offset (PCO), posterior condylar offset ratio (PCOR) and clinical outcomes following total knee arthroplasty (TKA) with anterior referencing (AR) or posterior referencing (PR) systems. We also assessed whether the PCO and PCOR changes, as well as patient factors were related to range of motion (ROM) in each referencing system. @*Methods@#This retrospective study included 130 consecutive patients (184 knees) with osteoarthritis who underwent primary posterior cruciate ligament (PCL)-substituting fixed-bearing TKA. The difference between preoperative and postoperative PCO and PCOR values were calculated. Clinical outcomes including ROM and Western Ontario and McMaster University (WOMAC) scores were evaluated. Furthermore, multiple linear regression analysis was performed to determine the factors related to postoperative ROM in each referencing system. @*Results@#The postoperative PCO was greater in the AR group (28.4 mm) than in the PR group (27.4 mm), whereas the PCO was more consistently preserved in the PR group. The mean postoperative ROM after TKA was greater in the AR group (129°) than in the PR group (122°), whereas improvement in WOMAC score did not differ between the two groups. Preoperative ROM was the only factor related to postoperative ROM in both groups. @*Conclusions@#There was no difference in postoperative PCO in AR and PR group and the PCO was not associated with postoperative ROM. PCO was more consistently preserved after surgery in the PR group. The postoperative PCO and PCOR changes did not affect the postoperative ROM. Furthermore, similar clinical outcomes were achieved in the AR and PR groups.

Association of preoperative pain in knee and external to knee with postoperative pain outcome after total knee arthroplasty

BACKGROUND: Preoperative pain in the symptomatic knee may predict postoperative pain severity in patients undergoing total knee arthroplasty (TKA). However, the effect of preoperative pain external to the knee on postoperative pain is unclear. This study evaluated postoperative pain outcomes in TKA patients according to the presence of preoperative pain in the knee only or in the knee and external to the knee.METHODS: We retrospectively assessed medical records of patients who underwent unilateral TKA. The relationship between reported preoperative pain characteristics and morphine equivalent consumption or numerical rating scale (NRS) pain scores on postoperative day (POD) 0–3 was assessed using a multivariable generalized linear model.RESULTS: In total, 3,429 adult patients who underwent their first TKA were included; 2,864 (83.5%) patients preoperatively experienced only knee pain and 565 (16.5%) knee pain with external to knee pain. Preoperative pain in the knee and external to the knee was associated with 5% higher morphine equivalent consumption on POD 0–3 compared to preoperative knee pain only (exponentiated regression coefficient: 1.05; 95% confidence interval: 1.02 to 1.09; P = 0.004). However, the NRS pain scores on POD 0, 1, 2, and 3 and adjuvant analgesics consumption (acetaminophen and ketorolac) on POD 0–3 were not significantly different between the two groups (P > 0.05).CONCLUSIONS: This study showed that there was an increase of morphine equivalent consumption during POD 0–3 in patients with preoperative knee pain with external to knee pain than in patients with preoperative only knee pain.

A Combined Closing Wedge Distal Femoral Osteotomy and Medial Reefing Procedure for Recurrent Patellar Dislocation with Genu Valgum

PURPOSE: Recurrent patellar dislocation is often associated with genu valgum. The purpose of this study was to analyze the short-term results of single-incision, closing-wedge distal femoral osteotomy (CWDFO) combined with medial reefing and lateral release for recurrent patellar instability with genu valgum. MATERIALS AND METHODS: Combined CWDFO/medial reefing/lateral release was performed on 10 knees. Clinical evaluation was based on pre- and postoperative Knee Society Score (KSS) and Kujala patellofemoral score. Radiographic evaluation was performed with reference to the weight-bearing line (WBL), the femorotibial angle (FTA), and the mechanical lateral distal femoral angles in the knee-standing view. RESULTS: At a mean follow-up of 20±11.7 months (range, 12–42 months), KSS scores improved significantly, from 46.7±5.2 preoperatively to 87±4.4 postoperatively (p<0.001), as did the Kujala score, from 44±8 preoperatively to 86.6±6.8 postoperatively (p<0.001). The WBL decreased significantly, from 76±7% preoperatively to 41±11% postoperatively (p<0.001). The FTA was improved significantly, from 12.7±1.7° preoperatively to 4±4° postoperatively (p<0.001), as was the mLDFA, from 83±4° preoperatively to 91±1.3° postoperatively (p<0.001). CONCLUSION: Use of single-incision CWDFO combined with medial reefing and lateral release prevents patellar dislocation, corrects deformity, and improves clinical outcomes.

Is Knee Magnetic Resonance Imaging Overutilized in Current Practice?

PURPOSE: To determine what proportion of patients visiting a tertiary knee clinic had pre-obtained knee magnetic resonance imaging (MRI) and to assess the impact of pre-obtained knee MRI on the selection of treatment plans. MATERIALS AND METHODS: Six hundred and eighty patients were enrolled from patients who visited our knee clinic during a 6-month period. The proportion of patients with pre-obtained knee MRI was calculated, and associations of sociodemographic factors, disease category, and finally selected treatment options with knee MRI pre-obtainment were investigated. A utility assessment panel of five orthopaedic surgeons was formed and established utility assessment criteria. Two rounds of utility assessment (before and after MRI review) were performed. RESULTS: Of the 680 patients, 185 (27%) had pre-obtained knee MRI. In the first round of utility assessment, 39%, 18%, and 43% of the 185 knee MRIs were evaluated as useful, equivocal, and arguably useless, respectively, and almost identical results were obtained in the second round. The proportion of assessed 'useful MRI' was higher in sports related injury (84%) and other conditions (91%) than in degenerative joint disease (18%) and nonspecific knee pain (31%). Utility assessment results among panels varied little for practice patterns and education duration. CONCLUSIONS: This study suggests clinicians should reconsider and counsel patients the expected utility of knee MRI acquisition.

Pure Varus Injury to the Knee Joint

A 30-year-old male was involved in a car accident. Radiographs revealed a depressed marginal fracture of the medial tibial plateau and an avulsion fracture of the fibular head. Magnetic resonance imaging showed avulsion fracture of Gerdy's tubercle, injury to the posterior cruciate ligament (PCL), posterior horn of the medial meniscus, and the attachments of the lateral collateral ligament and the biceps femoris tendon. The depressed fracture of the medial tibial plateau was elevated and stabilized using a cannulated screw and washer. The injured lateral and posterolateral corner (PLC) structures were repaired and augmented by PLC reconstruction. However, the avulsion fracture of Gerdy's tubercle was not fixed because it was minimally displaced and the torn PCL was also not repaired or reconstructed. We present a unique case of pure varus injury to the knee joint. This case contributes to our understanding of the mechanism of knee injury and provides insight regarding appropriate treatment plans for this type of injury.

Evaluation of Femoral Neck Bone Mineral Density and Radiographic Hand and Knee Osteoarthritis in a Korean Elderly Population

BACKGROUND: Reports on the relationship between osteoporosis and osteoarthritis (OA) have tended to disagree, especially in non-weight bearing joints such as the hand joints. We aimed to investigate the relationship between bone mineral density (BMD) and hand and knee OA in a general Korean elderly population. METHODS: We evaluated femur neck BMD and the hand and knee radiographs of 143 men and 123 women over 65 years of age who participated in a population-based cohort study. The Kellgren-Lawrence criteria for grading OA were implemented, and grade 2 or higher were categorized as radiographic OA. BMD was compared according to the existence of radiographic OA in the hand and knee using analysis of covariance, and correlation analyses were performed to explore the relationship between BMD and radiographic OA grade. RESULTS: After controlling for age and body mass index, there was no significant difference in BMD between participants with and without hand OA (p = 0.717 in male and p = 0.862 in female), between those with and without knee OA (p = 0.974 in male and p = 0.563 in female), and between those with only hand OA and those with only knee OA (p = 0.920 in male and p = 0.961 in female). Furthermore, there was no significant correlation between BMD and the radiographic OA grade of the hands (p = 0.182 in male and p = 0.897 in female) and knees (p = 0.245 in male and p = 0.098 in female). CONCLUSIONS: In our cohort of the general Korean elderly population, no association was found between osteoporosis and OA, regardless of the weight bearing status of the joints.

Prevalence of Osteoporosis in Female Patients with Advanced Knee Osteoarthritis Undergoing Total Knee Arthroplasty

This study sought to demonstrate bone mineral density (BMD) conditions in elderly female patients with knee osteoarthritis (OA) undergoing total knee arthroplasty (TKA). In addition, we sought to determine whether their BMD conditions differ from those of community-based females without knee OA. Finally we sought to determine whether clinical statuses are related to BMD in the knee OA patients. BMD conditions in 347 female patients undergoing TKA and 273 community-based females were evaluated. Additionally, comparative analyses of BMD between age and body mass index-matched knee OA groups (n=212) and the control groups (n=212) were performed. In the pre-matched knee OA group, regression analyses were performed to determine whether preoperative clinical statuses were related to BMD. Considerable prevalence of coexistent osteoporosis (31%) was found in the pre-matched knee OA patients undergoing TKA. We found no significant differences of the BMD T-scores and the prevalence of osteoporosis between the age and body mass index-matched knee OA and control groups. In the pre-matched knee OA patients, poorer preoperative clinical scores were related to poorer BMD T-scores in the proximal femur and/or lumbar spine. Our study suggests that more attention should be paid to identify and treat osteoporosis in elderly female patients with advanced knee OA undergoing TKA.

Prediction of Chronicity of Anterior Cruciate Ligament Tear Using MRI Findings

BACKGROUND: The estimation of anterior cruciate ligament (ACL) tear is required in certain cases involving legal and financial administration, such as the worker's compensation and/or insurance. The aim of this study is to propose and evaluate a quantitative evaluation instrument to estimate the chronicity of the ACL tear, based on the four magnetic resonance imaging (MRI) findings. METHODS: One hundred and fifty one cases of complete ACL tear confirmed by arthroscopy were divided into 4 groups according to the time from ACL injury to MRI acquisition: acute ( 1 year). The four MRI findings including ACL morphology, joint effusion, posterior cruciate ligament angle, and bone bruise were analyzed for temporal changes among the 4 groups. Binary logistic regression equations were formulated using the MRI findings to estimate the chronicity of ACL tear in a quantitative manner, and the accuracy of the formulated regression equations was evaluated. RESULTS: The four MRI findings showed substantial temporal correlation with the time-limits of ACL injury to be included in the estimation model. Three predictive binary logistic equations estimated the probability of the ACL injury for the three cutoff time-limits of 6 weeks, 3 months, and 1 year with accuracies of 82.1%, 89.4%, and 89.4%, respectively. CONCLUSIONS: A series of predictive logistic equations were formulated to estimate the chronicity of ACL tear using 4 MRI findings with chronological significance.

Evaluation of Factors Influencing Grip Strength in Elderly Koreans

OBJECTIVES: Grip strength has been used as a measure of function in various health-related conditions. Although grip strength is known to be affected by both physical and psychological factors, few studies have looked at those factors comprehensively in a population-based cohort regarding elderly Koreans. The aim of this study was to evaluate potential factors influencing grip strength in elderly Koreans. METHODS: We evaluated dominant hand grip strengths in 143 men and 123 women older than 65 years who participated in a population-based cohort study, the Korean Longitudinal Study on Health and Aging (KLoSHA). Individuals who had a history of surgery for musculoskeletal disease or trauma in the upper extremity were excluded. Factors assessed for potential association with grip strength were; 1) demographics such as age and gender, 2) body constructs such as height, body mass index (BMI), and bone mineral density (BMD), 3) upper extremity functional status using disabilities of the arm, shoulder and hand (DASH) scores, and 4) mental health status using a depression scale and the short form-36 (SF36) mental health score. Multivariate analyses were performed in order to identify factors independently associated with grip strength. RESULTS: Grip strengths of dominant hands in elderly Koreans were found to generally decrease with aging, and were significantly different between men and women, as expected. Multivariate analyses indicated that grip strength was independently associated with age, height and BMI in men (R2 = 21.3%), and age and height (R2 = 19.7%) in women. BMD, upper extremity functional status, or mental health status were not found to be associated with grip strength. CONCLUSIONS: This study demonstrates that in elderly Koreans, grip strength is mainly influenced by age and height in both men and women, and additionally by BMI in men. BMD or self-reported physical or mental health status was not found to influence grip strength in elderly Koreans. This information may be helpful in future studies using grip strength as a measure of function in elderly Koreans.

Anatomical Assessment of the Distal Femur and Tibia for Optimal Femoral Rotational Alignment in Total Knee Arthroplasty

PURPOSE: This study aimed 1) to identify the rotational axis of the femur that provides a balanced 90degrees flexion space in TKA, 2) to assess the changes in the flexion space in deep flexion, and 3) to assess the changes in rotational alignment, with using the posterior condylar axis (PCA) as a guide, and as the changes are related to asymmetric cartilage erosion of the posterior condyle. MATERIALS AND METHODS: The axial MR images of the distal femur in knee extension and the coronal images of the distal femur and the entire tibia at 90 and 130degrees were examined in 40 healthy adults. RESULTS: The clinical transepicondylar axis (TEA) provides a balanced 90degrees flexion space on average. The balanced flexion space in 90degrees became an asymmetrical space with relative narrowing of the medial side in 130degrees. Every 1 mm of asymmetrical cartilage erosion between the posterior condyles changed the femoral rotation by approximately 1degrees when using the PCA as a guide. CONCLUSION: This study suggests that the clinical TEA is the rotational reference that provides a balanced flexion space. When using the PCA as a rotational reference, a surgeon should consider the potential change in the rotational angle that is caused by asymmetrical cartilage erosion.

Prevalence of Radiographic Knee Osteoarthritis in Elderly Koreans

PURPOSE: This study was conducted to investigate the epidemiologic characteristics of knee osteoarthritis (OA) in elderly Koreans with respect to its detailed prevalence and association with demographic factors such as gender, age and body mass index (BMI). MATERIALS AND METHODS: Six hundred and ninety six subjects (men 298 and women 398) aged 65 years or older were recruited from an urban population. Radiographic evaluations were conducted using three plain radiographs (weight bearing anteroposterior view, 45 degree of flexion posteroanterior view, and the Merchant view). Radiographic severity was determined using the Kellgren-Lawrence (K/L) grading scale and radiographic OA was defined as K/L grade 2 or higher. Overall prevalence of OA was analyzed with regard to gender, age and BMI using multivariate logistic regression. RESULTS: The overall prevalence of knee OA in the study cohort was 38.1%. Women had the much higher prevalence of knee OA than men (53.8% vs. 17.1%). Female gender, obesity and ageing were associated with the risk of knee OA, but a female gender was found to be the strongest predictor for knee OA. CONCLUSION: This study documents that knee OA is highly prevalent among Korean elderly, and that elderly Korean women are at much greater risk of development of knee OA. It is hoped that our findings provide information that aids the creation of national health policies that better target the prevention and treatment of knee OA.

Differential Diagnosis of Knee Pain Commonly Encountered in Clinical Practice / 대한류마티스학회지

The knee is a complex structure and far from being the simple hinge joint of popular belief. Knee pain would not be properly understood unless one is familiar with the anatomy and understands the role of the various structures. For patient consultation or for selecting a treatment option, it is crucial to find the central cause of symptoms and functional disabilities of the patient based on a detailed history, a focused examination and, when indicated, the selective use of appropriate imaging and laboratory studies. The history taking should be comprehensive and include the demographic characteristics, past medical history, comprehending the associated trauma, pain characteristics and quality of life. Basic physical examination should include inspection of walking pattern and the knee, evaluation of joint effusion, range of motion and the location of tenderness, and precise assessment of joint stability. Although many advanced diagnostic tools are available, plain radiographs are frequently utilized as a primary tool to evaluate conditions of the knee joint for practical and economic reasons. A weight-bearing anteroposterior radiographs should be taken for appropriate evaluation of the condition of the tibiofemoral joint, and weight-bearing radiographs in semi-flexed position is valuable to evaluate the joint space more precisely. To evaluate the patellofemoral joint, axial and lateral views should be included in the routine radiographs. In practice, physicians need to be cautious not to easily reach the conclusion that the symptoms of the knee joint can be attributed to only a few clinical findings in consulting the patients with knee pain.

Patient Perspectives on Currently Controversial Issues in Total Knee Arthroplasty / 대한정형외과학회잡지

PURPOSE: To examined the level of patient knowledge and their perspectives about the controversial issues in total knee arthroplasty (TKA), and to evaluate the effect of a relevant explanation about the issues on the patient preferences for their particular option. MATERIALS AND METHODS: One hundred patients who visited our clinic and decided to undergo TKA were asked to complete a questionnaire asking about their knowledge and preference for 4 controversial issues: 1) surgical timing of the bilateral TKAs, 2) use of computer assisted surgery, 3) use of minimal invasive surgery, and 4) use of ceramic femoral component. The patients completed the same questionnaire after the advantages and disadvantages of each option had been explained using an explanatory document designed based upon what was documented in the literature. RESULTS: The patients were not well-informed about the issues and received their information through a non-professional source. The patients tended to prefer new options with claimed promises before an explanation. The patients preferred the options with safety, accuracy, and proven evidence after an explanation. Male patients tended to prefer simultaneous TKAs more than female patients. Younger patients preferred ceramic femoral component claimed to have better longevity more than older patients did. CONCLUSION: This study demonstrates that patients' knowledge of the current controversial issues is very limited, and that patient preferences would be significantly changed if they were given an explanation from a physician. Balanced information should be given to patients in order for them to reach a fair decision.

Posterior Double PCL Sign; A Case Report of Unusual MRI Finding of Bucket-handle Tear of Medial Meniscus: A Case Report / 대한정형외과학회잡지

Among the MRI signs of meniscal bucket handle tears, a double posterior cruciate ligament (PCL) sign manifests on the sagittal images as a low signal band anterior and parallel to the PCL. The mesially displaced fragment may be confined to the intercondylar notch. However, the torn fragment is rarely displaced to the posterosuperior region of the PCL. If it does occur, separation at the anterior horn may be assumed. We propose this type of lesion be called the posterior double PCL sign in contrast to the ordinary double PCL sign. We present a case showing the 'posterior double PCL sign' accompanying an anterior cruciate ligament injury.

Rigid Stepped Plate (RSP) for the Internal Fixation of the High Tibial Osteotomy / 대한정형외과연구학회지

PURPOSE: To compare the fixation power of the newly devised RSP (rigid stepped plate) with the L-plate by mechanical study and to prove the efficacy of the RSP. MATERIALS AND METHODS: Lateral closing wedge proximal tibial osteotomy was performed on the 10-monthsold porcine tibiae, which were fixed by 15 L-plates and 15 RSP's. Each group of 5 pairs of the specimen were applied to the Instron apparatus and loaded by compression, valgus, and varus bending. The fixation power was compared by the stiffness of each construct. RESULTS: Specimen fixed by the RSP's showed larger stiffness than those fixed by the L-plate. Even though the difference was not statistically significant in compression (p=0.465), it was statistically significant in valgus (p=0.047) and varus (p=0.009) bending. CONCLUSION: The RSP can be applied with minimal skin incision, will provide firm initial fixation to the osteotomy site, and seems to enable early range of motion exercise. It will improve the outcome of proximal tibial osteotomy by preventing excessive soft tissue dissection and complications resulting from long-term immobilization of the knee joint.

Anatomical Assessment of Distal Femur for Optimal Femoral Component Rotational Alignment in TKA / 대한정형외과학회잡지

PURPOSE: We evaluated the relationship among the various rotational reference axes of femoral component in TKA, and the potential change in rotational alignment when a posterior condylar axis (PCA) was used as a reference for different cartilage erosions between the medial and lateral posterior femoral condyles. MATERIALS AND METHODS: The study subjects included twenty male and twenty female volunteers. Axial MR image of the distal femur were used to measure the angles among the clinical transepicondylar axis (cTEA), surgical transepicondylar axis (sTEA), the PCA, and the AP axis. We then evaluated the difference in the amount of rotation between a normal and osteoarthritic model when the PCA was used as a rotational reference. RESULTS: The mean angle between cTEA and PCA was 5.4 degrees, and it was significantly greater in the female (6.5 degrees) than in the male group (4.3 degrees). The cTEA demonstrated a perpendicular relationship with the AP axis in both groups. The average angles between cTEA and sTEA were 3.2 degrees in the male group and 3.8 degrees in the female group. When we assumed complete erosion of the cartilage on the medial posterior condyle with preservation on the lateral side, the angles between the cTEA and PCA decreased by an average of 1.9 degrees in both groups. CONCLUSION: This study suggests that the two transepicondylar axes, which demonstrated greater than 3 degrees in angle-difference, should be defined clearly in scientific reports and in their application as rotational references in TKA. Some significant gender differences in the rotational profile were noted. When the PCA is used as a rotational reference, potential errors caused by the different amounts of cartilage erosion between the medial and lateral posterior condyles should be considered.

Short Term Clinical Results of Anatomical Reconstruction in the Posterolateral Corner of the Knee using Achilles Tendon Allograft / 대한정형외과학회잡지

PURPOSE: The purpose of this study was to evaluate the short term clinical results of the new anatomical reconstruction including 3 major posterolateral structures of the knee using a split Achilles allograft. MATERIALS AND METHODS: Eleven knees with posterolateral rotary instability underwent new anatomical posterolateral reconstruction between January 2002 and June 2003. The clinical results were assessed using the Lysholm score and Tegner activity level scales and physical examinations including posterolateral drawer test, dial tests at 30 and 90 degrees of knee flexion, varus stress tests at 0 and 30 degrees of knee flexion. RESULTS: Follow-up averaged 26 months (range, 12 to 29 months). The mean preoperative Lysholm score was 38.6 and at the time of latest follow-up, the mean score was improved to 72.5. The mean preoperative Tegner activity level was improved from 1.6 points to 3.3. Ten out of 11 patients showed negative conversion of the posterolateral drawer test and varus stress test at 30 degrees of flexion postoperatively. All patients, who showed positive signs on the external rotation-dial test at 30 degrees of knee flexion preoperatively, improved postoperatively. In eight patients, preoperative positive signs of varus stress tests at 0 degrees of knee flexion and the external rotation-dial test at 90 degrees of knee flexion disappeared postoperatively. CONCLUSION: This study suggests that the new anatomical reconstruction of posterolateral corner of knee is a reliable method providing excellent stability and satisfactory short term clinical results.