Biomedical subjects

C C Jiang

Publications and source records attributed to C C Jiang.

At least 19 recordsLinked to original sources

PubMed2000

Vibration arthrometry in the patients with failed total knee replacement.

This is a preliminary research on the vibration arthrometry of artificial knee joint in vivo. Analyzing the vibration signals measured from the accelerometer on patella, there are two speed protocols in knee kinematics: 1) 2 degrees/s, the signal is called "physiological patellofemoral crepitus (PPC)", and 2) 67 degrees/s, the signal is called "vibration signal in rapid knee motion". The study has collected 14 patients who had revision total knee arthroplasty due to prosthetic wear or malalignment represent the failed total knee replacement (FTKR), and 12 patients who had just undergone the primary total knee arthroplasty in the past two to six months and have currently no knee pain represent the normal total knee replacement (NTKR). FTKR is clinically divided into three categories: metal wear, polyethylene wear of the patellar component, and no wear but with prosthesis malalignment. In PPC, the value of root mean square (rms) is used as a parameter; in vibration signals in rapid knee motion, autoregressive modeling is used for adaptive segmentation and extracting the dominant pole of each signal segment to calculate the spectral power ratios in f < 100 Hz and f > 500 Hz. It was found that in the case of metal wear, the rms value of PPC signal is far greater than a knee joint with polyethylene wear and without wear, i.e., PPC signal appears only in metal wear. As for vibration signals in rapid knee motion, prominent time-domain vibration signals could be found in the FTKR patients with either polyethylene or metal wear of the patellar component. We also found that for normal knee joint, the spectral power ratio of dominant poles has nearly 80% distribution in f < 100 Hz, is between 50% and 70% for knee with polyethylene wear and below 30% for metal wear, whereas in f > 500 Hz, spectral power ratio of dominant poles has over 30% distribution in metal wear but only nonsignificant distribution in polyethylene wear, no wear, and normal knee. The results show that vibration signals in rapid knee motion can be used for effectively detecting polyethylene wear of the patellar component in the early stage, while PPC signals can only be used to detect prosthetic metal wear in the late stage.

Aged↗

PubMed2000

Vibration arthrometry in patients with knee joint disorders.

Physiological patellofemoral crepitus (PPC) is the vibration signal produced by the knee joint during slow motion (less than 5 degrees per second), which can be measured by vibration arthrometry (VAM). By using the autoregressive (AR) model for the PPC signals of patients with knee osteoarthritis, the study analyzes the PPC signals to evaluate the condition of patellar-femoral joint cartilage. Accordingly, we can divide osteoarthritis into three types, type 1: the cartilage of patellar-femoral joint is intact, the osteoarthritis found in the femoral-tibial joint surface; type 2: degeneration occurs in the surface cartilage of both the femoral-tibial joint and the femoral trochlea, but not on the patellar surface; type 3: both patellar-femoral and femoral-tibial joints have osteoarthritis. For the analysis, the intraclass distance of AR coefficients and spectral power ratio of dominant poles are adopted. Based on the proposed method, two cases of type 1, six of type 2, and 28 of type 3 were found in 36 cases of knee osteoarthritis. This is in agreement with the operative findings. For comparison, the PPC signals of 10 subjects with normal knees (without pain or wound history) were also measured. The results of analysis of the 10 normal subjects were consistent and clearly differentiable from those of the osteoarthritis patients. Therefore, the proposed method is efficient for the analysis of the condition of patellar-femoral joint cartilage and VAM may become an alternative way of noninvasive diagnosis of knee osteoarthritis.

Aged↗

PubMed2000

Modified Bankart procedure for recurrent anterior shoulder dislocation.

BACKGROUND AND PURPOSE: Recurrent anterior shoulder dislocation is a serious condition, for which the Bankart procedure is a standard treatment. Having made three modifications to the original procedure, we examined the efficacy of this modified Bankart procedure in the treatment of patients with recurrent anterior shoulder dislocation. PATIENTS AND METHODS: The medical records of 21 patients who received a modified Bankart procedure for recurrent anterior shoulder dislocation during the period from 1989 through 1998 were retrospectively analyzed. The average age at initial dislocation was 22 +/- 5 years. The average postoperative follow-up period was 41 +/- 16 months. Three of the patients complained of mild shoulder pain before their operation. RESULTS: The postoperative loss of external rotation and abduction compared with the nonoperated side was 9 +/- 4 degrees and 5 +/- 4 degrees, respectively. There were no limitations in daily activities during follow-up. No patient had shoulder pain after surgery. Redislocation occurred in one patient during the follow-up period. Patient satisfaction was rated as excellent by 20 (96%) patients and poor by one. CONCLUSION: This modified Bankart procedure is a technically easy operation with a low complication rate, a high rate of patient satisfaction, and a low redislocation rate. It is a procedure of choice for the management of traumatic recurrent anterior shoulder dislocation.

Adolescent↗

PubMed1998

Regional nerve block for total knee arthroplasty.

Femoral and sciatic nerve blocks have been used occasionally for unilateral total knee arthroplasty (TKA). In order to evaluate the effectiveness of this technique, combined femoral 3-in-1 and sciatic nerve blocks were performed in 20 cases of TKA, by the same surgeon. This surgeon also performed unilateral TKA under spinal anesthesia in another 20 cases. The anesthetic effectiveness of the two types of anesthesia was compared in terms of the time needed to complete the surgery, amount of intraoperative blood loss, and time interval until the first dose of analgesic. The results showed that the two types of anesthesia had comparable anesthetic effects. Ten of the 20 patients who had spinal anesthesia complained of postoperative urinary retention, while none of those who had nerve block had this complaint. Neither group experienced postpunctural headache, neurovascular damage, or drug-over-dose toxicity. We conclude that combined femoral 3-in-1 and sciatic nerve block is an effective anesthetic alternative for unilateral TKA.

Aged↗

PubMed1997

Evaluation of critical postoperative situations in orthopedic patients.

Most orthopedic surgery is elective. Even in the severely traumatized patient, orthopedic surgery is carried out after the patient's general condition stabilizes. Critical postoperative situations are still problems in orthopedic surgery. From November 1992 through May 1995, 7,325 patients were admitted to the orthopedic ward at the National Taiwan University Hospital and underwent surgery. We present a retrospective study of 78 postoperative orthopedic patients who were admitted to a surgical intensive care unit (ICU) during this period. Fourteen of these became vegetative or died. The patients admitted to an ICU were categorized into four groups, based on the type of surgery: arthroplasty (13 patients), spinal surgery (50), fracture other than spine (13), and others (2). The causes of ICU admission in each group were analyzed. The following operations were found to carry a high risk of postoperative complications: revisional total hip arthroplasty (one of four ICU-admitted patients died); debridement for infected total hip arthroplasty (two of two died); bilateral total knee arthroplasty (two of four died); and debridement of spinal infection (three of five died). The associated risk factors for ICU admission were: old age, underlying medical disease, pulmonary embolism in multiple fracture, respiratory compromise in spinal surgery, and massive blood loss. Great care should be taken when performing orthopedic surgery on patients with these risk factors.

Adult↗

PubMed1995

Role of flexors in knee stability.

The muscle strength of knee extensors is commonly used as an indicator of a patient's functional recovery following reconstruction of the anterior cruciate ligament (ACL). The knee flexors are dynamic stabilizers that prevent tibial anterior displacement and may reinforce the function of the ACL. The purpose of this study was to examine the relationship of knee flexor performance assessed by isokinetic dynamometer and clinical evaluations including KT-1000 stability tests, shuttle run tests, thigh and calf circumference and range of motion of the knee joint. Ten patients who received ACL reconstruction over a 3- to 5-year period were included in this study, as were 15 normal controls who were tested for comparison. There was no significant difference in the time taken for the shuttle run test between normal controls and patients who underwent ACL, but there was a positive correlation between the shuttle run test and laxity of the knee joint. The knee laxity of ACL patients was significantly greater than that of the normal controls under passive anterior force. However, no significant difference was seen in the stability test under active contraction of the knee extensors. In addition, a positive correlation was seen between the KT-1000 knee ligament arthrometry test results and both torque acceleration energy and the average power of the flexors. These results suggest that physical therapy for patients following ACL reconstruction should emphasize the explosiveness of knee flexors to help strengthen the dynamic stability of the knee joint and motor performance.

Adult↗

PubMed1995

MRI of meniscus and cruciate ligament tears correlated with arthroscopy.

Findings from magnetic resonance imaging (MRI) studies of 50 knees were retrospectively interpreted. The results were correlated with arthroscopic findings. Multiple pulse sequences were performed including sagittal double-echo, coronal T1-weighted and gradient echo, axial gradient echo or fat suppression imaging. Three-dimensional MRI was performed if there was a high suspicion of a tear of the anterior cruciate ligament. The individual positive predictive value, sensitivity, specificity and accuracy were calculated from the comparison between MRI and arthroscopic findings of the menisci, anterior cruciate ligament and posterior cruciate ligament. The following results were obtained: 1) Tears of the medial meniscus-positive predictive value, 72%; sensitivity, 87%; specificity, 86%; and accuracy, 86%. 2) Tears of the lateral meniscus-positive predictive value, 85%; sensitivity, 85%; specificity, 90%; and accuracy, 88%. 3) Tears of the anterior cruciate ligament-positive predictive value, 88%; sensitivity, 95%; specificity, 89%; and accuracy, 92%. 4) Tears of the posterior cruciate ligament-positive predictive value, 100%; sensitivity, 100%; specificity, 100%; and accuracy, 100%. It is concluded that MRI is a noninvasive and accurate method for detecting the internal derangement of the knee.

Adolescent↗

PubMed1994

Epiphyseal scar of the femoral head: risk factor of osteonecrosis.

PURPOSE: To find out whether a correlation exists between the presence of epiphyseal scar within the femoral head and osteonecrosis at examination with magnetic resonance (MR) imaging. MATERIALS AND METHODS: A total of 117 femoral heads in 60 patients were examined. Lipogenic factors (defined as either the use of steroid or alcohol abuse) were positive in 46 patients (average age, 37 years) and absent in 14 (average age, 47 years). Both hip joints were examined simultaneously at 1.5 T; three pulse sequences were used in each imaging study. All images were interpreted for type of epiphyseal scar and presence or absence of osteonecrosis. RESULTS: Six types of epiphyseal scar (A-F), each with a different shape, were seen. A total of 72 femoral heads had type A or B sealed-off scars; 32 of these 72 had osteonecrosis. Of the 45 femoral heads with type C, D, E, or F perforated scars, only one had osteonecrosis. The difference between these two groups was statistically significant (P < .001). CONCLUSION: The presence of a sealed-off epiphyseal scar was associated with a very high risk of osteonecrosis of the femoral head.

Adrenal Cortex Hormones↗

PubMed1994

Changes in the moment arms of the rotator cuff and deltoid muscles with abduction and rotation.

The behavior of the moment arms of the rotator cuff and deltoid muscles was studied during simple and combine movements of abduction and rotation about the glenohumeral joint. This was done by experimental measurement of excursions of the muscles in an in vitro cadaver model and by use of a multiple-regression analysis to delineate the changes in the moment arms as a function of abduction and rotation. The results demonstrated the potential of some rotator cuff muscles to contribute to both abduction and rotation, the sensitivity of the abductor moment-arm lengths to internal and external rotation and of the rotator moment-arm lengths to the degree of abduction, and the capacity of the abductor moment-arm lengths of the deltoid to increase with increasing abduction. Characterization of this behavior resulted in an increased understanding of the complex role of the rotator cuff and deltoid muscles about the gleno-humeral joint and provided quantitative descriptions of functional relationships. This study demonstrates the capacity of the infraspinatus and subscapularis muscles to contribute not only to external and internal rotation, respectively, but also to elevation of the arm in the plane of the scapula, a role for which these muscles have been given little or no consideration. Furthermore, it demonstrates that the contribution of the infraspinatus to abduction is enhanced with internal rotation while that of the subscapularis is enhanced with external rotation. Thus, dysfunction of the supraspinatus muscle need not preclude good elevation of the arm, and rehabilitation to reprogram and strengthen the remaining muscles becomes an important consideration.

Aged↗

PubMed1994

Posterior slope angle of the medial tibial plateau.

The overall average of the posterior slope of the medial plateau of the tibia as determined from the lateral radiography of the knee was 10 degrees +/- 4 degrees, with a range from 0 degrees to 20 degrees. This value was independent of age and gender and was unaffected by arthrosis as long as the arcuate contours of the medial socket were not eroded and could be identified by lateral radiography. While the average value of this posterior slope was similar to that of a cadaveric study, the range was much greater. The current practice of neglecting the preoperative posterior tibial slope and arbitrarily setting the tibial component at a predetermined posterior tilt angle failed to take into account the wide variation in posterior tibial slope.

Adolescent↗

PubMed1994

Vibration arthrometry of the knee with torn meniscus: a preliminary report.

Although projects using vibration signals generated by the joint to detect joint disorders are still experimental, vibration arthrometry has been shown to be useful in assessing meniscal pathology. A prospective study using vibration arthrometry to diagnose meniscal tears was carried out in 25 consecutive patients with knee injuries. They comprised 20 males and five females with an average age of 34 years. An arthroscopic examination of the injured knee was given to every patient. Six cases of medial meniscal tear, 12 lateral meniscal tear, and two torn discoid menisci were found. The remaining five cases had normal menisci. By correlating the vibration arthrography of the patients to their corresponding arthroscopic findings, 15 were found to be true-positive, five true-negative and five false-negative. There were no false-positive readings. The accuracy, sensitivity and specificity of the vibration arthrometry in diagnosing meniscal tear was 80%, 75% and 100%, respectively. Vibration arthrometry was shown to be a reliable, non-invasive diagnostic tool in diagnosing meniscal tear of the knee.

Adolescent↗

PubMed1994

Correlation between MRI and operative findings of the rotator cuff tear.

Rotator cuff disease is one of the most common causes of shoulder pain. Various methods have been used to evaluate this problem. In this study, we determine the accuracy of magnetic resonance imaging (MRI) of the shoulder in diagnosing the rotator cuff tear based on operative findings. Ten patients with a painful shoulder requiring operation received an MRI of the shoulder before surgery. A GE 1.5 Tesla MR scanner with a five-inch planar surface coil was applied and the diagnosis was confirmed by an experienced radiologist in the field of musculoskeletal MRI. All patients underwent surgery within two weeks of MRI examination. Nine of the 10 patients were shown to have rotator cuff tear by MRI. Among the nine MRI positive patients, eight were proven to have such lesions on operation (two massive tears, four moderate complete tears, and two bursal side tears). One false-positive result was found to be an adhesive capsulitis and supraspinatus tendinitis at operation. The remaining case, diagnosed as tendinitis by MRI, turned out to be a small incomplete tear on operation. Therefore, the sensitivity of MRI for rotator cuff tear in this study was 0.89. The overall accuracy was 80%. We concluded that MRI has a high accuracy in detecting the rotator cuff tear. False-positive and false-negative diagnoses were attributed to a severe tendinitis and an incomplete tear, respectively.

Adult↗

PubMed1994

Magnetic resonance imaging of rotator cuff lesions.

The purpose of this study was to evaluate the diagnostic performance of magnetic resonance imaging (MRI) in rotator cuff diseases. Forty consecutive patients studied by MRI from September 1990 to September 1992 were included in the study. MRI was performed on a 1.5 tesla MR scanner. Each MRI study was reviewed by two radiologists experienced in rotator cuff tendons. The MRI finding was compared with the surgical result. MRI sensitivity for all tears (partial and complete) was 1.0 (22/22), specificity 0.89 (16/18), accuracy rate 0.95 (38/40), and the predictive value 0.92 (22/24). Signal changes of the rotator cuff tendon (primary signs) were the most reliable criteria in diagnosis of the tear. Changes of subacromial and subdeltoid fat planes and bursa (secondary signs) were complimentary when primary signs were indeterminant. The direction of the long axis of abnormal signal intensity in the rotator cuff tendon may be a good indicator when differentiating tears from tendinitis. We conclude that MRI shows excellent performance in the determination of the presence or absence of a rotator cuff tear.

Adolescent↗

PubMed1994

Epiphyseal scar of the femoral head: a three-dimensional anatomic observation.

The purpose of this study was to inspect the three-dimensional structure of the epiphyseal scar of the femoral head. Three adult human femoral head specimens with a dense epiphyseal scar shown by radiography were used to study the morphology of the scar. One femoral head was cut in the coronal plane to show the cross-section. A trabecular pattern in the femoral head was demonstrated by radiography. The second femoral head specimen, was cut by a wafering saw in a plane parallel to the epiphyseal scar into 1.5 mm thick slices. Microradiographs of these specimen slices were taken to trace the scar from the proximal part of the femoral head to its distal end. In the third specimen, the epiphysis was chipped away to uncover the whole epiphyseal scar for a topographic examination by dissecting microscope and scanning electron microscope. The epiphyseal scar was found to consist of multiple layers of plate-like bony structure capping the metaphysis similar to an inverted cup with a defect adjacent to the fovea. Differences between the trabecular pattern in the epiphysis and metaphysis were distinctive. These morphologic characteristics of the femoral head should be taken into account when investigating stress distribution in the femoral head.

Adult↗

PubMed1994

Patellar thickness in total knee replacement.

The question of patellar thickness after total knee replacement (TKR) is an important issue. From November 1989 to June 1993, a total of 294 TKR were performed on 219 patients (34 males, 185 females) with an average age of 67 years. Tricon-M prostheses were used in TKRs performed before October 1992, and PCA prostheses were used after that date. In each TKR, all polyethylene patellar components used on patellar resurfacing were cemented in place. The average preoperative patellar thickness was 21.2 +/- 1.8 mm. The thickness was preserved in 106 knees, while for 53 knees, a slight increase in thickness (mean, 1.5 +/- 0.9 mm) was recorded, and for 120 knees, a slight decrease in thickness (mean, 1.5 +/- 0.8 mm) was recorded. Lateral retinacular release was performed in 96 knees (40%) of the 238 TKR with a Tricon-M prosthesis, but in only seven knees (17%) among the 41 TKR using the PCA prosthesis. Patellar subluxation and dislocation after TKR occurred in 13 knees of 11 patients (10 females, one male, mean body weight 63.5 kg) with the Tricon-M prosthesis. The mean time from arthroplasty to occurrence of patellar instability was eight months. Six knees were treated by proximal realignment procedure while seven knees were given conservative treatment, with good results and no recurrence reported. The use of a patellar cutting jig allows better control of patellar thickness when performing patellar resurfacing for small patella. No complications such as patellar fracture, infection or patellar component-loosening were encountered in the 294 TKRs performed.

Aged↗

PubMed1994

The excursion length of posterior cruciate ligament during range of motion in prosthetic knee.

Restriction of knee motion after total knee replacement was noted to be associated with lengthening of the posterior cruciate ligament during flexion of the knee which was replaced with a cruciate retaining knee prosthesis. The purpose of this study was to measure the excursion length of the PCL in the normal knee in four different cruciate-retaining knee prostheses, and in five cadaveric knees which were replaced with the Tricon prosthesis. For every knee, the tibial part was fixed on a stand and the femoral part was allowed to do flexion-extension motion upon the tibial plateau. The angle of the motion was monitored by the self-readout goniometer. A thin wire cord was attached to the proposed origin site of the PCL on the femur. The wire cord was passed through a tiny hook which was attached to the proposed insertion site of the PCL on the tibia and connected to a dial gauge. The excursion length of the PCL during 90 degrees flexion was measured. The same measurement was repeated five times in each cadaver knee and prosthetic knee studied, and in five knee specimens which were replaced with the Tricon prosthesis. The excursion length of the PCL during 0 degrees to 90 degrees of flexion in five cadaver knees averaged 0.08cm of lengthening. Three different origin sites of the ligament were designated to represent the anterior, middle and posterior part of the ligament.(ABSTRACT TRUNCATED AT 250 WORDS)

Biomechanical Phenomena↗

PubMed1993

Factors affecting knee motion after total knee arthroplasty: a cadaveric study of the collateral ligament.

Many of the factors affecting postoperative knee motion are related to collateral ligament imbalance. In a cadaveric knee model, the center of origin of either the medial or lateral collateral ligament was found to be located at the center of the quarter circle of the posterior femoral condyle. Two distances were identified: OD (from the center of origin of the collateral ligament to the distal tibiofemoral articulation) and OP (from the center of origin of the collateral ligament to the posterior tibiofemoral articulation). The effect of the collateral ligaments on knee motion was demonstrated by stimulating joint line elevation and ligamentous stretching in a cadaveric knee model. In the knee with an elevated joint line without concomitant anterior displacement (OD reduced, OP unchanged), the flexion limit was reduced. When the collateral ligaments were stretched in a knee with constant OD and OP, both the flexion and extension limits were reduced. A correct joint level can be achieved by measuring the OD, OP and the tension of the collateral ligaments during total knee arthroplasty.

Arthroplasty↗

PubMed1993

Effect of patellar thickness on kinematics of the knee joint.

Patellofemoral problems are common complications after total knee replacement. In order to investigate the effect of an increase in the patellar thickness on the kinematics of the knee joint, four intact embalmed cadaveric knee specimens were prepared to control the thickness of the patella and to measure: 1) the excursion lengths of the quadriceps muscles during knee flexion using a linear voltage displacement transducer; 2) patellar tracking and patellofemoral contact pressure using pressure sensitive Fuji prescale film; and 3) patellar movement during knee flexion using an image processing system. As the patellar thickness increased from the original dimension to a 7-mm increment, the excursion lengths of the quadriceps muscle during knee flexion did not vary significantly, but lateral patellar subluxation was clearly demonstrated by an increase in the patellofemoral contact pressure on the lateral femoral condyle and by lateral displacement of the patella. Increased patellar thickness in a total knee replacement is considered to be one of the causes of lateral subluxation. The importance of monitoring the patellar thickness using a patellar cutting jig is stressed.

Biomechanical Phenomena↗