Sung Ju Kim

Patient expectations of total knee replacement and their association with sociodemographic factors and functional status

We aimed to document the pre-operative expectations in Korean patients undergoing total knee replacement using an established survey form and to determine whether expectations were influenced by sociodemographic factors or pre-operative functional status. Expectations regarding 17 items in the Knee Replacement Expectation Survey form were investigated in 454 patients scheduled for total knee replacement. The levels and distribution patterns of summated expectation and of five expectation categories (relief from pain, baseline activity, high flexion activity, social activity and psychological well-being) constructed from the 17 items were assessed. Univariate analyses and multivariate logistic regression were performed to examine the associations of expectations with the sociodemographic factors and the functional status. The top three expectations were relief from pain, restoration of walking ability, and psychological well-being. Of the five expectation categories, relief from pain was ranked the highest, followed by psychological well-being, restoration of baseline activity, ability to perform high flexion activities and ability to participate in social activities. An age of < 65 years, being employed, a high Western Ontario and McMaster Universities osteoarthritis index function score and a low Short-form 36 social score were found to be significantly associated with higher overall expectations.

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.

Pain Management by Periarticular Multimodal Drug Injection After Anterior Cruciate Ligament Reconstruction: A Randomized, Controlled Study

PURPOSE We aimed to determine the efficacy of periarticular (PA) multimodal drug cocktail (MDC) infiltration for pain control after anterior cruciate ligament reconstruction with an autogenous bone-patellar tendon-bone graft. METHODS We randomly assigned 100 patients to five study groups (20 per group): control group, no injection; intra-articular (IA) ropivacaine group, IA injection of ropivacaine alone; IA MDC group, IA injection of MDC; PA MDC group, PA injection of MDC; and IA + PA MDC group, IA and PA injections of MDC. The MDC consisted of ropivacaine, morphine, ketorolac, epinephrine, and cefuroxime. The five groups were compared in terms of pain levels during the first night after surgery and on postoperative days 1, 2, and 14; patient satisfaction was assessed on postoperative day 14. RESULTS The PA MDC and IA + PA MDC groups had less pain during the first night than patients in the other three groups (P < .001) and were more likely to have the same amount of pain or less pain on postoperative day 1 than their preoperative expectation (P = .05). However, there were no group differences in patient satisfaction on postoperative day 14. No MDC-related side effect was reported. CONCLUSIONS The MDC injection, particularly when delivered periarticularly, provides an effective, safe means of reducing early postoperative pain after anterior cruciate ligament reconstruction at minimal cost. In addition, a single IA injection would have no value in pain relief, regardless of types of drugs. LEVEL OF EVIDENCE Level I, randomized controlled trial.

Complications and outcome of tibial lengthening using the Ilizarov method with or without a supplementary intramedullary nail: A CASE-MATCHED COMPARATIVE STUDY

We compared the complications and outcome of tibial lengthening using the Ilizarov method with and without the use of a supplementary intramedullary nail. In a retrospective case-matched series assembled from 176 patients with tibial lengthening, we matched 52 patients (26 pairs, group A with nail and group B without) according to the following criteria in order of importance: 1) difference in amount of lengthening (± 2 cm); 2) percentage difference in lengthening (± 5%); 3) difference in patients age (± seven years); 4) aetiology of the shortening, and 5) level of difficulty in obtaining the correction. The outcome was evaluated using the external fixator index, the healing index and an outcome score according to the criteria of Paley. It was found that some complications were specific to group A or B respectively, but others were common to both groups. The outcome was generally better in lengthenings with a nail, although there was a higher incidence of rectifiable equinus deformity in these patients.

Correlation of Magnetic Resonance Imaging Findings with the Chronicity of an Anterior Cruciate Ligament Tear

BACKGROUND Although several findings on magnetic resonance imaging have been demonstrated after anterior cruciate ligament injury, sequential changes on magnetic resonance imaging have not been comprehensively studied. We undertook to correlate four specific findings on magnetic resonance imaging of an anterior cruciate ligament injury over time. METHODS One hundred and forty-five patients with a complete tear of the anterior cruciate ligament confirmed by arthroscopy were divided, according to the time from the injury to the acquisition of the magnetic resonance image, into four groups: acute (within six weeks), subacute (more than six weeks to three months), intermediate (more than three months to one year), and chronic (more than one year). Four findings (anterior cruciate ligament morphology, joint effusion, posterior cruciate ligament angle, and bone bruise) were evaluated for each study group. RESULTS Strong correlations were found between the magnetic resonance imaging findings and the chronicity of the anterior cruciate ligament tear. Anterior cruciate morphology showed sequential changes with time (p < 0.001). Joint effusion decreased with time, with a significant difference occurring between the acute and subacute groups at six weeks (p < 0.001). The posterior cruciate ligament angle decreased gradually over time (p < 0.001). Finally, the signal contrast of bone-bruising decreased with time, with a significant change occurring after three months (p = 0.049). CONCLUSIONS Our study confirmed that these four magnetic resonance imaging variables are closely correlated with the chronicity of an anterior cruciate ligament tear, and estimation of the chronicity of the tear can be facilitated by an integrative interpretation of these findings.

Association between radiological findings and symptoms at the patellofemoral joint in advanced knee osteoarthritis.

We investigated the association between the radiological findings and the symptoms arising from the patellofemoral joint in advanced osteoarthritis (OA) of the knee. Four radiological features, joint space narrowing, osteophyte formation, translation of the patella and focal attrition were assessed in 151 consecutive osteoarthritic knees in 107 patients undergoing total knee replacement. The symptoms which were assessed included anterior knee pain which was scored, the ability to rise from a chair and climb stairs, and quadriceps weakness. Among the radiological features, only patellar translation and obliteration of the joint space had a statistically significant association with anterior knee pain (odds ratio (OR) 4.85; 95% confidence interval (CI) 1.83 to 12.88 and OR 11.23; 95% CI 2.44 to 51.62) respectively. Patellar translation had a statistically significant association with difficulty in rising from a chair (OR 9.06; 95% CI 1.75 to 45.11). Other radiological features, including osteophytes, joint space narrowing, and focal attrition had no significant association. Our study indicates that the radiological findings of patellar translation and significant loss of cartilage are predictive of patellofemoral symptoms and functional limitation in advanced OA of the knee.

Comparison between upper and lower limb lengthening in patients with achondroplasia: a retrospective study

Lengthening of the humerus is now an established technique. We compared the complications of humeral lengthening with those of femoral lengthening and investigated whether or not the callus formation in the humerus proceeds at a higher rate than that in the femur. A total of 24 humeral and 24 femoral lengthenings were performed on 12 patients with achondroplasia. We measured the pixel value ratio (PVR) of the lengthened area on radiographs and each radiograph was analysed for the shape, type and density of the callus. The quality of life (QOL) of the patients after humeral lengthening was compared with that prior to surgery. The complication rate per segment of humerus and femur was 0.87% and 1.37%, respectively. In the humerus the PVR was significantly higher than that of the femur. Lower limbs were associated with an increased incidence of concave, lateral and central callus shapes. Humeral lengthening had a lower complication rate than lower-limb lengthening, and QOL increased significantly after humeral lengthening. Callus formation in the humerus during the distraction period proceeded at a significantly higher rate than that in the femur. These findings indicate that humeral lengthening has an important role in the management of patients with achondroplasia.

The radiological parameters correlated with the alignment of the femoral component after Oxford Phase 3 unicompartmental knee replacement

The purpose of this study was to measure the radiological parameters of femoral component alignment of the Oxford Phase 3 unicompartmental knee replacement (UKR), and evaluate their effect on clinical outcome. Multiple regression analysis was used to examine the relative contributions of the radiological assessment of femoral component alignment in 189 consecutive UKRs performed by a single surgeon. The American Knee Society scores were compared between groups, defined as being within or outside recommended tolerances of the position of the femoral component. For the flexion/extension position 21 UKRs (11.1%) lay outside the recommended limits, and for posterior overhang of the femoral component nine (4.8%) lay outside the range. The pre-operative hip/knee/ankle (HKA) angle, narrowest canal distance from the distal femoral entry point of the alignment jig and coronal entry-point position had significant effects on the flexion/extension position. Pre-operative HKA angle had a significant influence on posterior overhang of the femoral component. However, there was no significant difference in American Knee Society scores relative to the position of the femoral component.

Clinical Implications of Femoral Anthropometrical Features for Total Knee Arthroplasty in Koreans.

Anthropometric features of Asians femora and their clinical relevance with regard to TKA are not rigorously investigated. We attempted to determine how well current prostheses accommodate femoral anthropometric features of Koreans and whether the presence of condylar or trochlear overhang or underhang adversely affects functional outcomes. We hypothesized that current prostheses do not accommodate Korean female femora well, and that overhang or underhang would adversely affect outcomes. Condylar and trochlear mediolateral (ML) widths and condylar anteroposterior (AP) heights were measured, and ML/AP ratios were calculated in 1025 osteoarthritic knees that underwent TKA. Besides gender difference, wide individual variation exists in condylar and trochlear widths and ML/AP aspect ratios for given AP heights. Size options of current prostheses could not cover the wide ranges of ML widths for given AP heights. The knees with condylar overhang more than 4mm showed lower maximum flexion angle postoperatively (P=0.005).