Max J. L. Chen

Ultrasound guidance in caudal epidural needle placement.

Background:This study was conducted to investigate the feasibility of using ultrasound as an image tool to locate the sacral hiatus accurately for caudal epidural injections. Methods:Between August 2002 and July 2003, 70 patients (39 male and 31 female patients) with low back pain and sciatica were studied. Soft tissue ultrasonography was performed to locate the sacral hiatus. A 21-gauge caudal epidural needle was inserted and guided by ultrasound to the sacral hiatus and into the caudal epidural space. Proper needle placement was confirmed by fluoroscopy. Results:In all the recruited patients, the sacral hiatus was located accurately by ultrasound, and the caudal epidural needle was guided successfully to the sacral hiatus and into the caudal epidural space. There was 100% accuracy in caudal epidural needle placement into the caudal epidural space under ultrasound guidance as confirmed by contrast dye fluoroscopy. Conclusions:Ultrasound is radiation free, is easy to use, and can provide real-time images in guiding the caudal epidural needle into the caudal epidural space. Ultrasound may therefore be used as an adjuvant tool in caudal needle placement.

Ultrasound-guided shoulder injections in the treatment of subacromial bursitis.

Chen MJL, Lew HL, Hsu TC, Tsai WC, Lin WC, Tang SFT, Lee YC, Hsu RCH, Chen CPC: Ultrasound-guided shoulder injections in the treatment of subacromial bursitis. Am J Phys Med Rehabil 2006;85:31–35. Objective:To investigate the treatment effectiveness between ultrasound-guided and blind injection techniques in the treatment of subacromial bursitis. Design:A total of 40 patients with sonographic confirmation of subacromial bursitis were recruited into this study. These patients were divided into blind and ultrasound-guided injection groups. The shoulder abduction range of motion was compared before injections and 1 wk after the completion of injections in both groups. Results:The shoulder abduction range of motion before injection in the blind injection group was 71.03 ± 12.38 degrees and improved to 100 ± 18.18 degrees 1 wk after the injection treatments. However, the improvement did not reveal significant statistical differences (P > 0.05). The shoulder abduction range of motion before injection in the ultrasound-guided injection group was 69.05 ± 14.72 degrees and improved to 139.29 ± 20.14 degrees 1 wk after the injection treatments (P < 0.05). Conclusions:Ultrasound may be used as an adjuvant tool in guiding the needle accurately into the inflamed subacromial bursa. The ultrasound-guided injection technique can result in significant improvement in shoulder abduction range of motion as compared with the blind injection technique in treating patients with subacromial bursitis.

Sagittal plane loading response during gait in different age groups and in people with knee osteoarthritis.

Chen CPC, Chen MJL, Pei YC, Lew HL, Wong PY, Tang SFT: Sagittal plane loading response during gait in different age groups and in people with knee osteoarthritis. Am J Phys Med Rehabil 2003;82:307–312. Objective To investigate the gait patterns and the sagittal ground reaction forces in different age groups and in people with knee osteoarthritis. Design Motion analysis and force platform data were collected for a total of 55 female subjects capable of independent ambulation. Subjects were divided into three groups consisting of the control group, the elderly group, and the osteoarthritis knee group. Gait parameters of walking velocity, cadence, step length, stride time, single- and double-support time, and sagittal ground reaction forces were obtained during comfortable walking speed. Gait analysis was performed in a tertiary hospital’s gait laboratory. Variables were analyzed using a univariate repeated-measures analysis of variance. Statistical significance was set at a value of P < 0.05. Results The osteoarthritis knee group had slower walking velocity, lower cadence, and longer stride time as compared with the elderly and young control groups (P < 0.05). In ground reaction force studies, the first peak time, expressed in percentage of gait cycle, was significantly longer in the osteoarthritis knee group (20.8 ± 3.2) as compared with the elderly (17.8 ± 2.0) and young control groups (17.1 ± 1.8, P < 0.01). The force during time of minimal midstance was larger in the osteoarthritis knee group (90.9 ± 5.3) as compared with the elderly and young control groups (P < 0.05). The second peak force was significantly smaller in the osteoarthritis knee group as compared with the young control group (P < 0.01). The force change in the midfoot region in the osteoarthritis knee and elderly groups revealed more loading force onto the midfoot region during midstance as compared with the young control group (P < 0.01). Conclusion Gait parameters in the elderly and osteoarthritis knee patients were characterized by slower walking velocity, lower cadence, shorter step length, longer stride time, and longer double-support time. Less heel contact and push-off forces were noticed in these two groups, with more loading force onto the midfoot during midstance.

Measurement of forefoot varus angle by laser technology in people with flexible flatfoot.

Chen MJL, Chen CPC, Lew HL, Hsieh WC, Yang WP, Tang SFT: Measurement of forefoot varus angle by laser technology in people with flexible flatfoot. Am J Phys Med Rehabil 2003;82:842–846. Objective The purpose of this study was to measure the forefoot varus angles in subjects with and without flexible flatfoot (FF) by using laser foot-scanning technology. Design In the rehabilitation laboratory of a tertiary medical center, 70 subjects with FF, ranging in age from 10 to 50 yr, were recruited. The control group consisted of 30 volunteers without clinical evidence of FF. A total of 100 positive casts were obtained by having their subtalar joints kept in a neutral position. The plantar surface of the positive cast was scanned by a Yeti 3D Foot Scanner. A straight line was drawn between the first and fifth metatarsophalangeal joints. The forefoot varus angle was measured from this line in relation to the line parallel to the ground. Results The mean forefoot varus angle was calculated to be 5.01 ± 4.51 degrees in our FF subjects, and 1.23 ± 1.96 degrees in the control group. Significant statistical difference in forefoot varus angle was noted between these two groups. Conclusions The laser foot-scanning technique offers fast and accurate measurement of the forefoot varus angles. An average forefoot varus angle of approximately 5 degrees was observed in subjects with FF, which was significantly greater than the subjects without FF. Therefore, we recommend the concept of incorporating adequate forefoot posting at the medial forefoot area of an insole in treating people with FF.

Ultrasonographic examination for inversion ankle sprains associated with osseous injuries.

Hsu C-C, Tsai W-C, Chen CPC, Chen MJ-L, Tang SF-T, Shih L: Ultrasonographic examination for inversion ankle sprains associated with osseous injuries. Am J Phys Med Rehabil 2006;85:785–792. Objective:The study attempted to evaluate the value of ultrasonography in determining the therapeutic strategy for patients with osseous injuries caused by ankle sprains. Design:A 10-MHz compact linear-array ultrasound transducer was used to assess patients with inversion ankle sprains. Eleven female and 12 male patients who had fractures detected by sonograms were included in the study. All 23 patients underwent radiographic examination for identification of fractures. Bone scintigraphy was performed for those who had negative x-ray findings. Results:Eighteen patients had distal fibular tip fractures, three patients had the fifth metatarsal base fractures, one patient had a talar neck fracture, and one patient had a navicular fracture. These fractures were all detected by ultrasonography and then proved even by radiography or by bone scans. All the 23 patients had anterior talofibular ligament injuries. Among these patients, 11 had anterior ankle-joint recess effusion, and two had additional anterioinferior tibiofibular ligament injuries. Six weeks of immobilization with the ankle fracture brace was prescribed for all the patients after the identification of fractures. Their ankle pain symptoms soon improved. Conclusions:Ultrasonography is valuable in evaluating tiny foot and ankle fractures and coexistent soft tissue injuries. It can guide the treatment for patients with osseous injuries caused by ankle sprains.

Transmetatarsal amputation prosthesis with carbon-fiber plate: Enhanced gait function

Tang SFT, Chen CPC, Chen MJL, Chen WP, Leong CP, Chu NK: Transmetatarsal amputation prosthesis with carbon-fiber plate: Enhanced gait function. Am J Phys Med Rehabil 2004;83:124–130. ObjectiveTo determine whether the design of a transmetatarsal amputation prosthesis with a carbon-fiber plate would improve gait pattern in patients with transmetatarsal amputations. DesignIn the gait laboratory in a tertiary medical center, eight male patients with transmetatarsal amputations were recruited. Nine able-bodied male volunteers were recruited as the control group. A full-length standard shoe and a transmetatarsal amputation prosthesis with a carbon-fiber plate were the footwear used. Our transmetatarsal amputation prosthesis included a custom-molded insole, a mounted toe filler, and a thin, lightweight, carbon-fiber plate incorporated directly beneath the insole. ResultsAfter wearing the transmetatarsal amputation prosthesis with a carbon-fiber plate, the results of the kinetic and kinematic studies were summarized. ConclusionThe transmetatarsal amputation prosthesis with a carbon-fiber plate improved gait pattern significantly in patients with transmetatarsal amputations. Drastic shoe modifications are not necessary to have the prosthesis inserted. The carbon-fiber plate functions like the spring-steel shank within the sole of the shoe. The carbon-fiber plate, the toe filler, and the total-contact insole are all mounted as a whole to ensure better foot contact. Therefore, our transmetatarsal amputation prosthesis with a carbon-fiber plate can be a good alternative choice of footwear in patients with transmetatarsal amputations.

Comparing the effects of different speech targets on cognitive event-related potentials: theoretical implications for evaluating brain injury.

Lew HL, Chen CPC, Chen MJL, Hsu THC, Tang SFT, Date ES: Comparing the effects of different speech targets on cognitive event-related potentials: Theoretical implications for evaluating brain injury. Am J Phys Med Rehabil 2002;81:524–527.

The Improvement of Pain Symptoms and Activities of Daily Living in People with Knee Osteoarthritis after Intra-articular Hyaluronic Acid Injection

Osteoarthritis (OA) is a slowly evolving articular disease that appears to originate in the cartilage and affects the underlying bone, soft tissues, and synovial fluid. This condition usually occurs late in life, principally affecting the large weight-bearing joints such as the knee. It is particularly disabling when the knees are affected, because it limits the ability to walk, to rise from a chair, and to use stairs. The treatment selections for OA knees include analgesic drugs, physiotherapy, intra-articular (IA) drug administration, and surgical total knee replacement. We chose IA hyaluronic acid injection as the treatment method as it was documented as a safe drug, and being at least as efficacious as a continuous treatment with naproxen for 26 weeks. In this study, clinical pain symptoms, and activities of daily living were assessed by using Lequesnes Index before and after IA knee hyaluronic acid injections in 25 patients with bilateral knee OA. One session of hyaluronic acid injection was given to both knees (weekly IA knee injections for a total of five weeks). Results revealed significant improvements in clinical pain symptoms, and performance of activities of daily living after the completion of IA knee hyaluronic acid injections. Therefore, we conclude that IA knee hyaluronic acid injections are effective in alleviating the clinical pain symptoms, and improving the deteriorated activities of daily living that were caused by knee osteoarthritis.