Chong Bum Chang

Causes and Predictors of Patient's Dissatisfaction After Uncomplicated Total Knee Arthroplasty

We aimed to identify the causes and predictors of patients dissatisfaction after total knee arthroplasty (TKA). Patients satisfaction was evaluated in 438 TKAs. Causes of patient dissatisfaction were identified using patient interview, physical examinations, laboratory and radiographic tests, and relevant medical consultations. Investigation of 33 dissatisfied knees identified knee-related symptoms in 16 knees (48.5%) and the symptoms unrelated to the replaced knee in 17 knees (51.5%). Multivariate logistic regression analysis revealed that worse preoperative Western Ontario McMaster University Osteoarthritis Index scale pain score and postoperative decrease in range of motion were significantly associated with postoperative dissatisfaction (odds ratio, 7.6 and 2.1, respectively). This study demonstrates that residual symptoms or dysfunctions not directly associated with the replaced knee could be a frequent cause of postoperative dissatisfaction after TKA in osteoarthritic patients.

Anatomical References to Assess the Posterior Tibial Slope in Total Knee Arthroplasty: A Comparison of 5 Anatomical Axes

There has been no consensus on an ideal anatomical reference to determine the posterior slope of tibia plateau. Posterior slope of the medial tibia plateau was measured with reference to a proposed mechanical axis (MA) and 5 clinically relevant anatomical references in 90 osteoarthritic knees of 66 female patients undergoing total knee arthroplasty. The MA was defined as the line connecting the midpoints of the medial tibia plateau and the tibial plafond, and 5 anatomical references included the anterior cortical line of tibia, anatomical axis of proximal and central tibia, posterior cortical line of proximal tibia, and fibular shaft axis. The average posterior slope was 10.6 degrees with reference to the MA, and the amount of posterior slope varied widely among the patients and depending on the anatomical reference used to measure. This study indicates that the anatomical reference used to measure the posterior slope should be identified in studies where posterior slope is used to evaluate the sagittal alignment of total knee arthroplasty.

Functional Disabilities and Satisfaction After Total Knee Arthroplasty in Female Asian Patients

This study was conducted to investigate functional disabilities and patient satisfaction in Korean patients after total knee arthroplasty (TKA). Of 372 female patients who had undergone TKA with a follow-up longer than 12 months, 261 patients (70.2%) completed a questionnaire designed to evaluate functional disabilities, perceived importance, and patient satisfaction. The top 5 severe functional disabilities were difficulties in kneeling, squatting, sitting with legs crossed, sexual activity, and recreational activities. The top 5 in order of perceived importance were difficulties in walking, using a bathtub, working, recreation activities, and climbing stairs. Severities of functional disabilities were not found to be correlated with perceived importance. The 23 patients (8.8%) dissatisfied with their replaced knees had more severe functional disabilities than the patients satisfied for most activities. The dissatisfied patients tended to perceive functional disabilities in high-flexion activities to be more important than the satisfied.

Comparisons of femoral tunnel position and length in anterior cruciate ligament reconstruction: modified transtibial versus anteromedial portal techniques.

PURPOSE We aimed to compare the modified transtibial and anteromedial (AM) portal techniques of anterior cruciate ligament reconstruction with respect to femoral tunnel position and length, as well as to identify factors associated with tunnel length. METHODS After exclusions, 105 primary anterior cruciate ligament reconstructions (55 in transtibial group and 50 in AM portal group) were studied. Femoral tunnel positions were assessed on postoperative tunnel-view radiographs, and tunnel lengths were measured during surgery. Differences between femoral tunnel positions in the coronal plane and lengths in these 2 groups were examined, and factors associated with tunnel lengths were investigated. RESULTS The AM portal group had a significantly more oblique femoral tunnel position than the transtibial group. However, femoral tunnels in the AM portal group were substantially shorter than tunnels in the transtibial group (34.2 v 43.3 mm, P < .001); the proportions of knees with femoral tunnels measuring less than 30 mm in the AM portal and transtibial groups were 26% and only 2%, respectively. In addition, a more oblique femoral tunnel position and a shorter distal femur mediolateral width were found to be significantly associated with a shorter femoral tunnel. CONCLUSIONS This study shows that the AM portal technique can achieve a more oblique femoral tunnel position but that resultant tunnels are substantially shorter than tunnels produced by the modified transtibial technique.

Evaluation of anatomic references for tibial sagittal alignment in total knee arthroplasty.

The authors aimed to demonstrate the relationship between the sagittal mechanical axis of the tibia and other reference axes of the tibia and fibula in patients with advanced osteoarthritis of the knee joints, and then to identify a reliable landmark in order to minimize posterior tibial slope measurement errors. We evaluated 133 osteoarthritic knees with neutral or varus deformity in 64 female and 8 male patients. Axial computed tomographic images of whole tibiae including knee and ankle joints were obtained and reconstructed using 3-dimensional imaging software. Angles between the mechanical axis (MA), the tibial anatomical axis (TAA), the anterior tibial cortex (ATC) and the fibular shaft axis (FSA) were measured, and then medial and lateral tibial slope angles were measured using all axes. Mean angles between MA and the other anatomical reference lines (TAA, ATC and FSA) were 0.9, 2.2 and −2.1°, respectively. The mean values of lateral tibial slopes with respect to MA, TAA, ATC and FSA were 8.7, 10, 12 and 7.3, respectively, and their intra- and inter-observer reliabilities were higher than those of medial tibial slopes. Although posterior tibial slope change markedly according to the reference axis used, the axes used in conventional TKA showed significant correlations with each other, and thus, may be used safely if differences with the mechanical axis are considered. Moreover, the lateral tibial slope might have advantages over the medial tibial slope in terms of restoration of the natural tibial slope.

Additional pain relieving effect of intraoperative periarticular injections after simultaneous bilateral TKA: a randomized, controlled study.

The authors investigated the clinical value of intraoperative periarticular multimodal drug injections (PMDI) in patients on continuous epidural analgesia after simultaneous bilateral TKAs. In 55 patients scheduled to undergo simultaneous bilateral TKAs, one knee was randomly assigned to the PMDI group for which intraoperative periarticular injections were administered and the other knee was assigned to the No-PMDI group for which the injections were not done. These two groups were compared for pain level (during the operation night and on postoperative days (POD) 1, 4, and 7), functional recovery (ability to perform straight leg raising on POD 1 and maximum flexion on POD 7), patient satisfaction (POD 7), and the incidence of wound complications. The PMDI group showed a lower pain level during the operation night and on POD 1 than the No-PMDI group, but no differences in pain levels were observed between the groups on POD 4 or 7. Furthermore, no significant group differences were found in terms of functional recovery, patient satisfaction. No wound complication has been occurred in the PMDI group. This study demonstrates that PMDI provides additional pain relief limited to the immediate postoperative period but does not improve pain relief after POD 1, patient satisfaction and functional recovery.

Does periarticular injection have additional pain relieving effects during contemporary multimodal pain control protocols for TKA?: A randomised, controlled study

Although the analgesic effects of periarticular multimodal drug injection (PMDI) after TKA have been well documented, there is little information about additional pain relieving effects of PMDI incorporated to contemporary multimodal pain control protocols which have been proved to provide excellent analgesia. We performed a parallel-group, randomised, controlled study to determine whether PMDI provides additional clinical benefits on contemporary multimodal analgesic protocols including preemptive analgesics, continuous femoral nerve block, and IV-PCA. Eighty-seven patients were randomized to a PMDI group (n=45) or to a No-PMDI group (n=42). Pain level and opioid consumption were compared as primary outcomes. The incidences of narcotic and ropivacaine related side effects and complications, functional recovery, and satisfaction were also compared. The PMDI group experienced less pain during the operation night and the 1st postoperative day and showed lower opioid consumption over 24h after surgery. However, the PMDI group had a higher VAS pain score on the 1st postoperative day than during the operation night. No group differences in side-effects and complication incidences, functional recovery, and satisfaction were found. This study demonstrates that PMDI provides additional pain relief and reduces opioid consumption only during the early postoperative period in patients managed by the contemporary pain management protocol following TKA.

Correlations Between Commonly Used Clinical Outcome Scales and Patient Satisfaction After Total Knee Arthroplasty

UNLABELLED Patient satisfaction is becoming increasingly important as a crucial outcome measure for total knee arthroplasty. We aimed to determine how well commonly used clinical outcome scales correlate with patient satisfaction after total knee arthroplasty. In particular, we sought to determine whether patient satisfaction correlates better with absolute postoperative scores or preoperative to 12-month postoperative changes. Patient satisfaction was evaluated using 4 grades (enthusiastic, satisfied, noncommittal, and disappointed) for 438 replaced knees that were followed for longer than 1 year. Outcomes scales used the American Knee Society, Western Ontario McMaster University Osteoarthritis Index scales, and Short Form-36 scores. Correlation analyses were performed to investigate the relation between patient satisfaction and the 2 different aspects of the outcome scales: postoperative scores evaluated at latest follow-ups and preoperative to postoperative changes. The Western Ontario McMaster University Osteoarthritis Index scales function score was most strongly correlated with satisfaction (correlation coefficient=0.45). Absolute postoperative scores were better correlated with satisfaction than the preoperative to postoperative changes for all scales. LEVEL OF EVIDENCE Level IV (retrospective case series).

Differences between Sagittal Femoral Mechanical and Distal Reference Axes Should Be Considered in Navigated TKA

In computer-assisted TKA, surgeons determine positioning of the femoral component in the sagittal plane based on the sagittal mechanical axis identified by the navigation system. We hypothesized mechanical and distal femoral axes may differ on lateral views and these variations are influenced by anteroposterior bowing and length of the femur. We measured angles between the mechanical axis and distal femoral axis on 200 true lateral radiographs of the whole femur from 100 adults. We used multivariate linear regression to identify predictors of differences between the axes. Depending on the method used to define the two axes, the mean angular difference between the axes was as much as 3.8° and as little as 0.0°, with standard differences ranging from 1.7° to 1.9°. Variation between the two axes increased with increased femoral bowing and increased femoral length. Surgeons should consider differences between the mechanical axes and distal femoral axes when they set the sagittal plane position of a femoral component in navigated cases. Our findings also may be relevant when measuring rotation of the femoral component in the sagittal plane from postoperative radiographs or when interpreting femoral component sagittal rotation results reported in other studies.Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Normative Temporal Values of CRP and ESR in Unilateral and Staged Bilateral TKA

C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) play helpful roles in determining the presence of infection after TKA. To provide baseline values, we documented normative temporal values of CRP and ESR in unilateral and staged bilateral TKAs for osteoarthritis. Levels of CRP and ESR were evaluated before surgery and on the first, second, fifth, seventh, fourteenth, forty-second, and ninetieth postoperative days in 320 uncomplicated primary TKAs. C-reactive protein and ESR levels were compared in three groups: unilateral (108 knees), first knee bilateral (106 knees), and second knee bilateral (106 knees) groups. All three groups exhibited similar temporal patterns. Mean CRP levels increased rapidly, reaching a peak on the second day and decreased to less than the normal reference level on the forty-second day. They returned to preoperative levels on the ninetieth day. Mean ESR levels peaked on the fifth day and returned close to the preoperative levels only on the ninetieth day. Wide variations were observed and many cases (43%) did not follow the typical patterns. C-reactive protein had greater fold changes, less frequent atypical temporal patterns, and lower correlation between preoperative and postoperative levels than ESR. Our findings should help surgeons interpret CRP and ESR to determine the presence of infection after TKA.Level of Evidence: Level I, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.