Yin-Chun Tien

Augmentation of tendon-bone healing by the use of calcium-phosphate cement

The healing of a hamstring graft to bone is the weak link in the reconstruction of a cruciate ligament using this donor material. We therefore investigated the augmentation of healing at the tendon-bone interface using calcium-phosphate cement (CPC). We performed semitendinosus autograft reconstructions of the anterior cruciate ligament on both knees of 22 New Zealand white rabbits. The interface between the grafted tendon and the bone tunnel for one knee was filled with CPC. Six rabbits were killed at the end of the first and second post-operative weeks in order to evaluate the biomechanical changes. Two rabbits were then killed sequentially at the end of weeks 1, 3, 6, 12 and 24 after operation and tissue removed for serial histological observation. Histological examination showed that the use of CPC produced early, diffuse and massive bone ingrowth. By contrast, in the non-CPC group of rabbits only a thin layer of new bone was seen. Mechanical pull-out testing at one week showed that the mean maximal tensile strength was 6.505 +/- 1.333 N for the CPC group and 2.048 +/- 0.950 N for the non-CPC group. At two weeks the values were 11.491 +/- 2.865 N and 5.452 +/- 3.955 N, respectively. Our findings indicate that CPC is a potentially promising material in clinical practice as regards its ability to reinforce the fixation of the tendon attachment to bone and to augment the overall effectiveness of tendon healing to bone.

Dome corrective osteotomy for cubitus varus deformity

Between 1994 and 1998, 15 patients had corrective dome-shaped osteotomy of the humerus for posttraumatic cubitus varus deformity. Thirteen patients had surgery before puberty and two patients had surgery after puberty. In the prepuberty group, all the osteotomies were done by a posterior approach with triceps muscle splitting, and cross pins were used to fix the osteotomy. In the postpuberty group, the osteotomies were done by a posterior approach with olecranon osteotomy, and reconstructive plates were used for fixation. The average followup was 2 years and 4 months. Preoperative carrying angle ranged from 19° to 31° varus (average, 26.2° ) and postoperative carrying angle ranged from 7° to 15° valgus (average, 10.7°). No loss of correction was observed and all osteotomies united. The preoperative and postoperative differences of the lateral condylar prominence index ranged from −67% to +6% (average, −30.1%). After reviewing these cases, a dome-shaped osteotomy was found to have the following advantages for correction of cubitus varus deformity: the osteotomy site is more stable than a lateral closing wedge osteotomy for maintaining the correction obtained; the domed osteotomy avoids having the lateral condyle becoming prominent; and the posterior scar is more cosmetically acceptable than the lateral scar in the lateral closing wedge osteotomy.

Supracondylar Dome Osteotomy for Cubitus Valgus Deformity Associated with a Lateral Condylar Nonunion in Children

BACKGROUND Open reduction, autogenous bone-grafting, and internal fixation for the treatment of established nonunion of the lateral condyle associated with a cubitus valgus deformity has a high rate of complications. As a consequence, we developed a new technique that includes in situ compression fixation of the lateral condylar nonunion and a dome-shaped supracondylar osteotomy of the distal aspect of the humerus through a single posterior incision. METHODS Eight consecutive patients were treated with the new surgical technique between 1994 and 2000. The mean age at the time of surgery was 8.6 years. The mean interval between the lateral condylar fracture and surgery was 4.9 years. The mean preoperative radiographic humerus-ulna angle was 31 degrees of valgus. The postoperative results were classified with a modification of the scoring system described by Dhillon et al., which assesses pain, weakness, range of motion, the humerus-ulna angle, and prominence of the medial epicondyle on a 12-point scale. RESULTS All eight lateral condylar nonunions achieved union within three months postoperatively. The mean postoperative humerus-ulna angle was 5.5 degrees of valgus. All of the supracondylar dome osteotomies healed uneventfully, and there was no loss of correction postoperatively. The mean duration of follow-up was 4.5 years. The overall results were excellent in two patients, good in four patients, and fair in two patients. CONCLUSIONS With better exposure of the lateral condylar nonunion through a posterior approach, we can effectively stabilize the lateral condylar nonunion and avoid postoperative loss of motion and osteonecrosis of the condyle. With a dome-shaped supracondylar osteotomy, we can correct the cubitus valgus deformity and avoid the development of a medial epicondylar prominence. With careful selection of patients, this new technique can be an effective method to treat this clinically challenging problem.

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.

Semitubular Plates for Acutely Displaced Midclavicular Fractures: A Retrospective Study of 111 Patients Followed for 2.5 to 6 Years

Objectives: We designed this study to determine the usefulness of semitubular plates for acute displaced or comminuted fractures of the midclavicle. Design: Nonrandomized retrospective study. Setting: A secondary transfer hospital specializing in orthopaedics. Patients: From May 1997 to July 2001, 121 patients were treated with a 92% (111) follow-up rate. The mean follow-up time was 3.5 years (range, 2.5 to 6 years). Intervention: Semitubular plates using 4.5-mm cortical or 6.5-mm cancellous screws and wire as necessary. Main Outcome Measurement: The functional result was evaluated by the Disabilities of the Arm, Shoulder and Hand (DASH) score at the time of admission for implant removal in 82 patients or at the end of follow-up by telephone in 29 patients. Results: Most (107 of 111) fractures healed within 6 months. Three patients with implant failure due to backing out of the screws healed after surgical revision. One patient had an infected nonunion with a poor result. The other 110 patients had good results. No implant breakage was noted. No other major complications were noted except for 1 deep infection. No bone graft was needed, even with comminution at the fracture site. Of the 107 patients with uneventful union, 82 had hardware removal. The other 25 were diagnosed as having union both radiographically and clinically and did not have their hardware removed. Conclusion: Overall, 95% of patients were satisfied with the surgical procedure. We suggest that a semitubular plate with 4.5-mm cortical and 6.5-mm cancellous screws with wire augmentation if necessary is a reliable procedure for acute severely displaced or comminuted midclavicular fractures.

EFFECTS OF PULSED LOW-INTENSITY ULTRASOUND ON HUMAN CHILD CHONDROCYTES

The effect of pulsed low-intensity ultrasound (PLIUS) on human articular chondrocytes was evaluated in an in vitro 3-D agarose gel culture model. Chondrocytes isolated from young childrens articular cartilage of ablated polydactylia were embedded in gel after expansion and exposed to PLIUS on the third day after embedding. Another group of cells was exposed to sham PLIUS as a control. Different intensities of PLIUS treatment-18 mW/cm(2), 48 mW/cm(2), 72 mW/cm(2) and 98 mW/cm(2) (1.0 MHz, with burst duration of 200 micros repeated at 1.0 kHz)-were administered for 20 min/d, and the medium was replaced twice a week. The cultures were evaluated for aggrecan synthesis by enzyme-linked immunosorbent assay (ELISA), type II collagen production by Western blotting or ELISA and cell proliferation by total DNA measurement. The PLIUS was found to increase aggrecan synthesis in a time-dependent manner. The maximal response was observed at an intensity of 48 mW/cm(2). After 14 d of exposure at this intensity, the aggrecan synthesis was 214 +/- 26% of control, and type II collagen synthesis was 148.5 +/- 8.0% of control. However, PLIUS treatment revealed no significant influence on cell proliferation, confirming that the stimulation of aggrecan and type II collagen synthesis by PLIUS was not the result of an increase in chondrocyte cell proliferation. In addition, it was found that human chondrocytes harvested from older donors become less responsive to PLIUS. From this in vitro 3-D study of cultured human chondrocytes, our findings suggest that PLIUS may be applied to the tissue engineering of cartilage constructs.

Open Total Talar Dislocation─Report of Two Cases

Total dislocation of talus from all its surrounding joints (tibiotalar, subtalar and talonavicular) is an extremely rare injury. Because of its rarity, only few case reports can be found in the literature. In the review of the literature, infection and AVN are the most commonly encountered complications that affect the outcome of these severe injuries. Herein we report two cases of open total talar dislocation. Immediate debridement, reduction of the talus, and primary skin closure was done followed by cast immobilization. After more than 2 years follow up, neither infection nor AVN was found. We conclude that reimplantation of the talus is preferable if the wound is relatively clean. Talectomy, or combined with tibiocalcaneal fusion should be reserved for later salvage procedure.

MRI of multifocal kaposiform haemangioendothelioma without Kasabach–Merritt phenomenon

Kaposiform haemangioendothelioma is a rare soft-tissue tumour of infants and children, and presents as a moderately aggressive malignancy. We present the MRI findings of a histologically proven case of Kaposiform haemangioendothelioma without Kasabach-Merritt phenomenon or typical skin changes. Our case also reveals that the multiple foci of the cutaneous tumour have different MRI morphologies. These findings have not been reported in the literature to date.

Supracondylar dome osteotomy for cubitus valgus deformity associated with a lateral condylar nonunion in children : Surgical technique

BACKGROUND Open reduction, autogenous bone-grafting, and internal fixation for the treatment of established nonunion of the lateral condyle associated with a cubitus valgus deformity has a high rate of complications. As a consequence, we developed a new technique that includes in situ compression fixation of the lateral condylar nonunion and a dome-shaped supracondylar osteotomy of the distal aspect of the humerus through a single posterior incision. METHODS Eight consecutive patients were treated with the new surgical technique between 1994 and 2000. The mean age at the time of surgery was 8.6 years. The mean interval between the lateral condylar fracture and surgery was 4.9 years. The mean preoperative radiographic humerus-ulna angle was 31 degrees of valgus. The postoperative results were classified with a modification of the scoring system described by Dhillon et al., which assesses pain, weakness, range of motion, the humerus-ulna angle, and prominence of the medial epicondyle on a 12-point scale. RESULTS All eight lateral condylar nonunions achieved union within three months postoperatively. The mean postoperative humerus-ulna angle was 5.5 degrees of valgus. All of the supracondylar dome osteotomies healed uneventfully, and there was no loss of correction postoperatively. The mean duration of follow-up was 4.5 years. The overall results were excellent in two patients, good in four patients, and fair in two patients. CONCLUSIONS With better exposure of the lateral condylar nonunion through a posterior approach, we can effectively stabilize the lateral condylar nonunion and avoid postoperative loss of motion and osteonecrosis of the condyle. With a dome-shaped supracondylar osteotomy, we can correct the cubitus valgus deformity and avoid the development of a medial epicondylar prominence. With careful selection of patients, this new technique can be an effective method to treat this clinically challenging problem.

Ankle Arthrodesis: Internal Non-Compression Arthrodesis versus Internal Compression Arthrodesis

Ankle arthrodesis is still considered to be the standard treatment for most disabling types of ankle arthritis, but fusion methods are varied. We report our experience of ankle arthrodesis and compare a group of 34 cases treated by Blairs non-compression arthrodesis to another group of 32 cases treated by internal compression arthrodesis using two crossed screws. The same surgeon performed all the operations. The Blairs non-compression arthrodesis group included 21 males and 13 females with an average age of 42 y/o (range 18-70 y/o) and an average follow up period of 38.6 months (range 26-62 months). The union rate was 91.2% and the average union time was 5.6 months (range 2-10 months). There were three cases of non-union. The cross-screw compression arthrodesis group included 20 males and 12 females with an average age of 45 y/o (range 20-86 y/o) and an average follow up period of 38.3 months (range 15-81 months). The union rate was 96.9% and the average union time was 2.7 months (range 1.5-4.4 months). There was one case of non-union. We conclude that our cross-screws compression arthrodesis with its shorter fusion time was found to be superior to the Blairs non-compression arthrodesis.