Shen-Kai Chen

Revision of Ankle Arthrodesis

From 1989 to 1996, we treated 18 cases (10 males, eight females; average age 48.2 years) of failed ankle arthrodesis by revision of ankle arthrodesis and followed their progress for at least two years. The average time interval between original surgery and revision was 17.3 months. Revisions were needed due to infection in one case, nonunion in 10 cases, and malalignment in seven cases. The salvage operations included debridement in the infected case, refreshed pseudoarthrosis in nonunion cases, and corrective osteotomy in malalignment cases. Sixteen cases were fixed by crossed screws with internal compression, one infected case was fixed by an external fixator, and one case with bone loss was fixed with buttress plate. The average follow-up period was 40.4 months. There was one nonunion and two delayed unions, with an ultimate fusion rate of 94%. The average AOFAS ankle-hindfoot score was 70.9 at final follow up. There was one excellent result (5.6%), five good results (27.8%), 11 fair results (61%), and one poor result (5.6%), and the overall results were poorer compared with our series of primary arthrodesis. The time to fusion also took longer in the revision cases (average 2.7 months in primary cases and 4.8 months in revision cases). Fusion techniques that ensure solid union in a functional position are essential. If an ankle arthrodesis fails, however, revision is a salvage procedure that can achieve an acceptable result.

Angle Analysis of Haglund Syndrome and its Relationship with Osseous Variations and Achilles Tendon Calcification

Background: Haglund syndrome is a cause of posterior heel pain. The prominent posterosuperior projection into the retrocalcaneal bursa is thought to be a major etiology. Many methods have been proposed to measure the posterosuperior projection of the tuberosity into this bursa. The Fowler angle and the parallel pitch lines are the most frequently used. However, the relation between symptomatic Haglund syndrome and the measuring methods, especially the Fowler angle and parallel pitch lines, is not clear. The purposes of this paper were to study the predictive value of the most frequently used measurement methods to evaluate bursal impingement and to determine if other osseous variations and Achilles tendon calcification are associated with the development of Haglund syndrome. Methods: From October, 1996, to March, 2003, we evaluated 37 heels in 31 patients with symptomatic Haglund syndrome, and 40 heels in 27 individuals without posterior heel pain. On a lateral view radiograph, the Fowler angle, and the parallel pitch lines were measured, in addition to Achilles tendon calcification and the osseous variations, such as a posterior calcaneal step spur or plantar osseous projection. Results: The average Fowler angles in the control group and study group were 62.31 ± 7.79 degrees and 60.14 ± 7.01 degrees, respectively. There was no statistically significant difference (p = 0.490). The positive parallel pitch lines in the symptomatic group were 56.8% and in the control group 42.5%. There was no statistically significant difference (p = 0.474) between the groups. Conclusions: No statistically significant differences were noted between the groups concerning the Fowler angle and parallel pitch lines. The posterior calcaneal step spur and Achilles tendon calcification were statistically significant between these two groups. The Fowler angle and parallel pitch lines were of little predictive value for the Haglund syndrome.

Subtalar Arthrodesis for Subtalar Arthritis

Primary subtalar arthritis is not common except in cases of generalized arthritis such as rheumatoid arthritis. The majority of subtalar arthritis results from intraarticular calcaneal fractures. Arthrodesis seems to be the only way to solve this problem. Thirteen patients (15 feet) were treated with subtalar arthrodesis at KMCH. Preoperative diagnosis included 13 feet with traumatic arthritis secondary to a calcaneal fracture, one foot with rheumatoid arthritis and one foot with primary osteoarthritis. The mean follow up period was 24.9 months. Lateral approach without fibular osteotomy was done with decompression if there was entrapment syndrome and the arthrodesis were accomplished with use of staples for internal fixation. Eleven (85%) of the patients were satisfied with the results. Objectively, the results were excellent after 11 arthrodesis (73%), good or fair after three (20%), and poor after one (7%). There was no nonunion. Complications occurred in 1 patient who developed superficial wound infection, and in 1 patient with staple loosening. Though there was no case of nonunion, the fusion time was rather long. This might have been due to the fixation method because staples can not provide compression force which accelerates union. We believe subtalar arthrodesis is appropriate for isolated subtalar arthritis unless there are associated talonavicular or calcaneocuboid arthritis in which case triple arthrodesis will be more appropriate.

Idiopathic Frozen Shoulder Treated by Arthroscopic Brisement

Arthroscopic brisement serves as an useful procedure in the treatment of idiopathic frozen shoulder. This series included 186 shoulders with a diagnosis of idiopathic frozen shoulder who had symptoms for an average of 8 months and failed conservative treatment of at least 12 weeks. Using the arthroscopic brisement (distension, debride, release and manipulation) to treat the idiopathic frozen shoulder, it is beneficial not only to detect the inside lesion but also a solution to the problem of stiffness. The average follow-up time was 23 months from 6 months to 5 years. One hundred and seventy (92%) of 186 shoulders had yielded overall satisfactory results in this series. There was no relationship between the end result and the initial pathologic condition. We believe that arthroscopic brisement is an effective way of shortening the course of frozen shoulder and should be considered when conservative treatment has failed.

Underlying Mechanisms of Tai-Chi-Chuan Training for Improving Balance Ability in the Elders

ObjectiveTo compare balance ability between elderly individuals who practiced Tai-Chi-Chuan (TCC) for average 9.64 years and elderly individuals who did not practice TCC and its relationship with lower extremity muscle strength and ankle proprioception.MethodsTwenty-five elderly volunteers were divided into two groups according to their TCC practcing experience. Sixteen were TCC group and the other nine were control population. Subjects completed a static balance test and ankle proprioception test using a custom-designed evaluation system, and concentric and eccentric knee extensor and flexor muscle strength tests. Subjects stood on the plate form to measure the proprioception in functional standing position which was differed from the previous studies. Multiple linear regressions were also used to predict the important factor affecting balance.ResultsTCC group performed better than the control group in balance, proprioception, and muscle strength of lower extremity. The proprioception was the most important factor related to balance ability and it can be accounted for explaining 44% of variance in medial-lateral sway direction, and 53% of variance in antero-posterior sway direction. The proprioception may be a more important factor which affecting the balance ability.ConclusionTCC training is recommended to the elders; as it can improve balance ability through better proprioception.

THE ANALYSIS OF UPPER LIMB MOVEMENT AND EMG ACTIVATION DURING THE SNATCH UNDER VARIOUS LOADING CONDITIONS

This study investigates upper limb movement and electromyography (EMG) signals during snatch under various loading conditions and discusses results from six lifting phases. Qualisys motion analysis and Noraxon EMG systems were used to record upper limb movement and muscle activity. When lifting heavy weights, the maximum shoulder flexion angle exceeded 180° in the rise phase and thus, was higher than when lifting lower weight categories. The deltoid and biceps muscles exhibited higher activity during this phase when lifting heavy weights. It can be inferred that the deltoid muscle is activated in this phase in order to maintain the shoulder in an abducted position, and to maintain hyperflexion of the biceps. Muscle activity of the deltoid and biceps in the second pull phase also increased significantly during heavy weight lifting. We infer that the effective use of these two muscles in the second pull phase would produce higher peak barbell vertical velocity, increasing the amount of weight can be lifted. Muscle activity for the latissimus dorsi during first pull showed a statistically significant increase when lifting heavy weights. This ability by the latissimus dorsi to generate higher velocities early in the concentric phase (downswing) possibly contributed to the improved final performance during heavy weight lifting.

Surgical treatment of complete acromioclavicular separations.

A retrospective study of fifty-two patients (48 cases followed up), with Allman-Tossy grade III acromioclavicular separations, who were treated with coracoclavicular reconstruction by Mersilene prosthetic substitute (Mersilene tape with polyester suture, 5 mm wide, 30 cm, Ethicon), was carried out. The average follow up was 38 months, with the longest being 10 years, and the shortest being 8 months. The average age of the patients was 32 years, with a range from 20 to 62 years. Two groups were divided by age. Although the younger age group showed better results than the elder one in pain, range of motion and return to previous occupation or sports, the overall outcome was satisfactory in 41 of 48 (86%) followed patients. For the grade III acromioclavicular separation patients, surgical reconstruction with Mersilene looping provides a reliable result including use of the arm for sports or repetitive work.

EVALUATION OF INTERNAL ROTATOR MUSCLE FATIGUE ON SHOULDER AND SCAPULAR PROPRIOCEPTION

Background and aim: Fatigue of internal or external rotators of the glenohumeral may alter proprioception in the shoulder joint. Fatigue of shoulder muscles can affect the three-dimentional kinematics of the scapula, and may also alter the glenohumeral and scapular movement pattern, with changes in the scapulohumeral rhythm. Previous studies have shown that with arm elevation, there is a decreased upward rotation of the scapula as well as reduced posterior tilt and external rotation movements with shoulder rotator cuff muscle fatigue. Our aim is to examine the effect of internal rotator fatigue on the proprioception of glenohumeral and scapular active repositioning. Methods: Twenty young healthy subjects with an average age of 20 years were recruited. Each subject performed repetitive concentric exercise (internal rotation) to induce muscles fatigue, which was confirmed by a muscle strength testing using a hand-held dynamometer. Measurement of active repositioning with glenohumeral and scapula repositioning were examined before and after internal rotator fatigue via the three-dimensional (3D) electromagnetic motion analysis system. Results: Fatigue of internal rotators did not affect the glenohumeral and thoracoscapluar joint proprioception (P > 0.05). Conclusion: The findings showed that fatigue of shoulder internal rotators did not contribute to alteration in glenohumeral and scapular proprioception.

Salvage operation for neglected ankle fractures.

From 1986 to 1993, 49 cases of untreated or poorly treated ankle fractures who received salvage surgery were followed up for an average of 36.4 months. The patients included 31 males & 18 females with an average age of 41.6y/o and the time interval from initial injury to reconstructive surgery average due 17.6 months. They were classified and treated according to their grade of reduction and degree of arthrosis. The surgical methods included arthrotomy & joint debridement, revised open reduction, lower tibial osteotomy and ankle arthrodesis, depending on different individual conditions. After surgery, all cases had symptomatic relief and functional improvement with an average score increased from 26.3 preoperatively to 86.8 at follow up. The goals of ankle fractures is as articular fractures, they are treated by surgical anatomic reduction with rigid fixation as early as possible in order to provide good functional results. Nevertheless they are varied in neglected ankle fractures according to their individual conditions: open reductions were performed on cases with no or little arthritic change even though arthrosis might occur later because, if necessary, future conversion to osteotomy or arthrodesis would be easier. As for late cases with advanced arthritis, ankle arthrodesis were done by compressive arthrodesis with necessary bone graft to secure fusion in an optimal position.

Irreducible Metatarsophalangeal Joint Dislocation of the Lesser Toes

Irreducible metatarsophalangeal joint dislocation of the lesser toes is a rare injury. We present a 37-year-old man who was injured in a motorcycle accident and dislocated the first to third metatarsophalangeal joints and fractured the fourth metatarsal head. The left first metatarsophalangeal joint was reduced successfully through the closed method, but multiple attempts at closed reduction under local anesthesia failed to reduce the dislocated second and third metatarsophalangeal joints. We performed a dorsal incision between the second and third metatarsals, and the metatarsal heads were found to be entrapped under the plantar plate. Dislocation reduction was performed without damage to the plantar plate, and one Kirschner wire was used to fix the fourth metatarsal head fracture. The pin was removed 8 weeks after surgery, and the patient regained normal gait and returned to work and his previous physical activity level without recurrent dislocation.