Radiographic Evaluation of the Normal Distal Tibiofibular Syndesmosis in Neutral to Dorsiflexion on Weight-Bearing / 대한스포츠의학회지

Purpose@#Reliable landmarks of ankle syndesmosis change in various positions is important for managing ankle injury. The purpose of our study was to investigate and compare radiographic landmarks of normal ankle in various positions. @*Methods@#The study involved both ankle radiographs of 30 subjects (15 males, 15 females) without clinical or radiographic abnormality. Tibiofibular clear space (TFCS) and tibiofibular overlap (TFO) were measured on anteroposterior (AP) and mortise radiographs in non-standing (NS) and standing (S) neutral and dorsiflexion 10° (DF10) and 20° (DF20). The radiographic measurements were used to calculate means, standard deviations, and intra- and interobserver reliabilities, and compare TFCS and TFO in various positions and genders. @*Results@#On the AP view, the mean TFCS in NS, S, DF10, and DF20 positions were 4.00±0.97, 4.00±0.83, 4.35±0.95, and 4.45±0.89 mm and the mean TFO on the same positions were 6.58±2.27, 4.27±1.90, 3.44±1.96, and 2.38±1.91 mm. On the mortise view, the mean TFCS in NS, DF10, and DF20 positions were 3.62±0.88, 4.08±0.86, and 3.88±0.97 mm and the mean TFO on the same positions were 3.57±2.13, 2.31±1.77, and 3.57±2.14 mm. The reliabilities in all positions except TFCS on some positions were excellent. No measurement was significantly different between females and males except TFO in NS on mortise view (p=0.006) and DF10 on AP view (p=0.032). @*Conclusion@#Increase of TFCS and decrease of TFO on AP view reflects syndesmosis change from NS to DF20 on standing. Clinically, the effect of weight-bearing and reliability of TFO should be considered.

Vaccination for Athletes: Evidence and Recommendations / 대한스포츠의학회지

As interest in sports rapidly grows in Korea, fostering of elite athletes and preservation of the athletic ability no longer became the task of advanced countries only. In that aspect, health of athletes and their associated coaches, athlete trainers, team members such as team doctors, and even their families is certainly a matter of concern. Especially when it comes to the inoculation of infectious disease prevention, it needs to be considered as one of the most economical and effective ways to promote health in sports people as well as elite athletes. The purpose of this article is to go over the specific circumstances of the athletes and related literatures on vaccination. In addition, we provide recommendations on the vaccination of athletes regarding the actual situation of sports in Korea.

Biomechanical Comparison Study of Three Fixation Methods for Proximal Chevron Osteotomy of the First Metatarsal in Hallux Valgus

BACKGROUND: Fixation of proximal chevron metatarsal osteotomy has been accomplished using K-wires traditionally and with a locking plate recently. However, both methods have many disadvantages. Hence, we developed an intramedullary fixation technique using headless cannulated screws and conducted a biomechanical study to evaluate the superiority of the technique to K-wire and locking plate fixations. METHODS: Proximal chevron metatarsal osteotomy was performed on 30 synthetic metatarsal models using three fixation techniques. Specimens in group I were fixated with K-wires (1.6 mm × 2) and in group II with headless cannulated screws (3.0 mm × 2) distally through the intramedullary canal. Specimens in group III were fixated with a locking X-shaped plate (1.3-mm thick) and screws (2.5 mm × 4). Eight metatarsal specimens were selected from each group for walking fatigue test. Bending stiffness and dorsal angulation were measured by 1,000 repetitions of a cantilever bending protocol in a plantar to dorsal direction. The remaining two samples from each group were subjected to 5 mm per minute axial loading to assess the maximal loading tolerance. RESULTS: All samples in group I failed walking fatigue test while group II and group III tolerated the walking fatigue test. Group II showed greater resistance to bending force and smaller dorsal angulation than group III (p = 0.001). On the axial loading test, group I and group II demonstrated superior maximum tolerance to group III (54.8 N vs. 47.2 N vs. 28.3 N). CONCLUSIONS: Authors have demonstrated proximal chevron metatarsal osteotomy with intramedullary screw fixation provides superior biomechanical stability to locking plate and K-wire fixations. The new technique using intramedullary screw fixation can offer robust fixation and may lead to better outcomes in surgical treatment of hallux valgus.

The Operative Management of Navicular Stress Fractures in Adolescence / 대한족부족관절학회지

PURPOSE: The aim of this study is to evaluate the effectiveness of surgical treatment in adolescent patients suffering from navicular stress fracture. MATERIALS AND METHODS: A total of 11 adolescent patients aged 14 to 19, who underwent an operation for navicular stress fracture between 2005 and 2008 were recruited. Clinical outcomes were evaluated by the American Orthopaedic Foot and Ankle Society (AOFAS) midfoot score and visual analogue scale (VAS) score. RESULTS: The mean VAS score before the operation was 7.7. A score of 2.9 was confirmed at final follow up after the operation. The mean final follow-up period was 22.1 months. There was a statistically significant improvement in the VAS score between before and after the operation (p=0.01), and similarly, the AOFAS score also showed an improvement, from 46.5 to 80.7 (p=0.01). The pain that remained after the operation, according to the VAS score, was severe in three patients (27.3%), tolerable in seven patients (63.6%), and free of pain in one patient (9.1%). CONCLUSION: In navicular stress fracture in adolescents, careful selection of patients who could benefit from surgical treatment is recommended.

Morphologic Analysis of the Fifth Metatarsal Stress Fracture: The Precise Coronal and Sagittal Location / 대한스포츠의학회지

From a biomechanical standpoint, the main pathologic abnormality of fifth metatarsal stress fracture is the location where repetitive tensile stress concentrated. Decreasing tensile force in this region would be a proper treatment. Therefore, the purpose of this study is to evaluate the precise sagittal and coronal location of the fifth metatarsal stress fracture. Between June 2012 and May 2013, 38 athletes with a fifth metatarsal stress fracture were treated. To evaluate the precise sagittal location of the fracture, the entire length of the fifth metatarsal was measured and the distance from tuberosity to the fracture line was measured. To evaluate the precise coronal location of the fractures, coronal computed tomography images were obtained for incomplete fracture cases. The fracture location was classified as four quadrants. Thirty patients were classified into zone III fracture. However, the fracture is located in zone II for remaining eight cases. The median value of ratio between whole length and the distance from tuberosity to the fracture was 0.35 (range, 0.29–0.40) Among 33 incomplete fracture cases, there were 28 patients whose fracture developed in plantolateral quadrant, four patients at the lateral side and a patient for plantar side. The main pathologic abnormality is at the plantar lateral side because of the repetitive stress concentrated there.

Paratrooper's Ankle Fracture: Posterior Malleolar Fracture

BACKGROUND: We assessed the frequency and types of ankle fractures that frequently occur during parachute landings of special operation unit personnel and analyzed the causes. METHODS: Fifty-six members of the special force brigade of the military who had sustained ankle fractures during parachute landings between January 2005 and April 2010 were retrospectively analyzed. The injury sites and fracture sites were identified and the fracture types were categorized by the Lauge-Hansen and Weber classifications. Follow-up surveys were performed with respect to the American Orthopedic Foot and Ankle Society ankle-hindfoot score, patient satisfaction, and return to preinjury activity. RESULTS: The patients were all males with a mean age of 23.6 years. There were 28 right and 28 left ankle fractures. Twenty-two patients had simple fractures and 34 patients had comminuted fractures. The average number of injury and fractures sites per person was 2.07 (116 injuries including a syndesmosis injury and a deltoid injury) and 1.75 (98 fracture sites), respectively. Twenty-three cases (41.07%) were accompanied by posterior malleolar fractures. Fifty-five patients underwent surgery; of these, 30 had plate internal fixations. Weber type A, B, and C fractures were found in 4, 38, and 14 cases, respectively. Based on the Lauge-Hansen classification, supination-external rotation injuries were found in 20 cases, supination-adduction injuries in 22 cases, pronation-external rotation injuries in 11 cases, tibiofibular fractures in 2 cases, and simple medial malleolar fractures in 2 cases. The mean follow-up period was 23.8 months, and the average follow-up American Orthopedic Foot and Ankle Society ankle-hindfoot score was 85.42. Forty-five patients (80.36%) reported excellent or good satisfaction with the outcome. CONCLUSIONS: Posterior malleolar fractures occurred in 41.07% of ankle fractures sustained in parachute landings. Because most of the ankle fractures in parachute injuries were compound fractures, most cases had to undergo surgical repairs.

Pseudoaneurysm after Proximal Metatarsal Osteotomy for Hallux Valgus Correction: A Case Report / 대한족부족관절학회지

Occurrence of pseudoaneurysm in the foot and ankle is rare, and is usually caused by traumatic injury or by iatrogenic intervention. Iatrogenic pseudoaneurysms in the foot and ankle have been observed after rearfoot and ankle fusions, ankle arthroscopy, endoscopic and open plantar fasciotomy, tibial osteotomy with limb lengthening, midfoot amputation, and Lapidus procedure. We report on a patient who developed a pseudoaneurysm of the dorsal metatarsal artery following correction of hallux valgus. The patient underwent proximal chevron osteotomy and Akin phalangeal osteotomy. The feeding artery was ligated and the pseudoaneurysm was excised.

Epidermal Cyst in the Foot and Ankle / 대한정형외과학회잡지

PURPOSE: To document post-excision recurrence rates for epidermal cysts of the foot and ankle by location. MATERIALS AND METHODS: The authors retrospectively reviewed epidermal cysts confirmed histologically by excisional biopsy in 37 patients (male 20, female 17) from 2004 to 2011. Cyst locations and sizes were analyzed and preoperative and postoperative pain levels were compared using a visual analogue scale (VAS). Rates of recurrence and patient satisfaction levels were also measured. RESULTS: Epidermal cysts occurred most commonly on the 1st toe (15 cases, 40.6%), followed by the ankle (7 cases, 18.9%), 2nd toe (6 cases, 16.2%), 3rd toe (4 cases, 10.8%), 4th toe (1 case, 2.7%), 5th toe (2 cases, 5.4%), and heel (2 cases, 5.4%). Average cyst size in 35 cases was 15.5x15.0x7.9 mm. VAS reduced from 6.5 preoperatively to 1.0 postoperatively. Cysts recurred in 7 cases (18.9%); on the 1st toe in 5 and on the 2nd toe in 2. Thirty patients (81.0%) were very satisfied with treatment results, 2 patients (5.4%) were satisfied, and 5 (13.5%) were not satisfied. Recurrence occurred in 4 cases, and in one of these cases the cyst recurred after second excision. CONCLUSION: The excision of epidermal cysts in the foot and ankle area was found to have an 18.9% recurrence rate. To achieve good results, the precise location of cysts should be determined by imaging study before excision, and cysts must be excised completely.

The Size of Calcaneus in Koreans / 대한족부족관절학회지

PURPOSE: Open reduction and internal fixation of calcaneal fracture using plate has been used. While numerous plates have been manufactured, most of the conventional plates are designed for westerners, realistically the size is larger for Korean. The domestic products, on the other hand, often have the undesirable screw holes and path. Therefore, we measured the radiologic parameter of Korean calcaneus for providing the plate and screw hole placements. MATERIALS AND METHODS: We measured the outer lines and angles with over the 20 years old 291 females and 322 males. A: Length of inferior plane of calcaneus, B: Length of anterior plane of calcaneus, C: Length from line A to sinus tarsi, D: Length from line A to posterior point of posterior facet, E: Length from line A to calcaneal tuberosity, F: Length of posterior facet, G: Length from anterior point of line A to C, H: Length from line C to line D, a: Angle between A and B, b: Gissane angle, c: Bohler angle, d: Calcaneal pitch angle using Marosis m-view(R). RESULTS: Mean A, B, C, D, E, F, G, H were 63.6, 26.4, 23.2, 43.7, 40.5, 26.9, 12.8, 18.1 mm. Mean a, b, c, d angle were 105.8, 122.4, 32.4, 20.5degrees. Male's calcaneus is significantly bigger than female's (p<0.001). CONCLUSION: AP calcaneus length 63.6 mm, maximal height 43.7 mm is considered to be helpful in making the Korean calcaneal plate.

Pigmented Villonodular Synovitis in Forefoot (A Case Report) / 대한족부족관절학회지

Pigmented villonodular synovitis (PVNS) is a slowly, progressive, proliferative disorder of synovial tissue characterized by villous or nodular changes of synovial-lined joints, bursae, and tendon sheaths and most frequently affects the large joints, with the knee and hip. A few studies have been reported that occurred PVNS in small joint, but mainly in hands. It is a very rare condition that occurs in the small joints of the forefoot. We have experienced the case, which developed in small joint of the forefoot, and performed total synovectomy. After the operation, there was no recurrence. We report a case of PVNS in forefoot with a review of the literature.

Ultrasonographic Evaluation of Flexor Hallucis Longus Tenosynovitis in Sports Players / 대한스포츠의학회지

The purpose of this study was to investigate the ultrasonographic features of flexor hallucis longus (FHL) tenosynovitis in sports players. High-resoluted ultrasound was used to measure the thickness and echogenicity of the flexor hallucis longus at the posteromedial ankle, especially the fibro-osseous tunnel, for 60 sports players (120 feet). They were compared with their asymptomatic feet. There were two group; group 1 was symptomatic feet, 2 was asymptomatic. The 36 males (72 feet) and 24 females (48 feet) had an average age of 21.3 years (range, 18.23 years). Thickness, echogenicity of the tendon on each group were evaluated by the ultrasonography and the results were statistically analyzed. The mean thickness of the FHL on group 1 was 3.4+/-1.2 mm, 2.1+/-1.3 mm on group 2. There was significant difference between two groups (p=0.002). The thickness of FHL based on gender and location was not significant different (p>0.05). For group 1, increased thickness of the FHL and reduced echogenicity, peritendious fluid collection were observed in ultrasonographic findings.Increased thickness (>3 mm) and hypoechoic lesion, peritendinous fluid collection of the tendon were sonographic findings at the posteromedial ankle in the FHL tenosynovitis. The authors suggested that Ultrasonography is a valuable and alternative tool for the evaluation of FHL tenosynovitis.

Fifth Metatarsal Stress Fracture / 대한족부족관절학회지

Fractures located at the metaphyseal/diaphyseal junction at the base of the fifth metatarsal were first described by Sir Robert Jones in 1902. However, ever since, there has been disagreement and debate regarding the diagnosis, classification, pathomechanics, the incidences, and potential causes of delayed unions and nonunions, and the optimal method of treatment. It appears to be widely agreed that proximal fractures of the metaphyseal/diaphyseal region of the fifth metatarsal are prone to delayed union or even nonunion. Several classifications of proximal fifth metatarsal stress fractures have been devised. Torg et al. classified fractures involving the proximal part of the diaphysis of the fifth metatarsal into three types. The Torg classification is a good grading system that can be used to determine the type of surgery needed as well as for the prediction of prognosis. The "plantar gap" might add to the decision-making process for surgery and improve the prediction of patient prognosis. In addition, the new classification using 'plantar gap' might be used for classification of fifth metatarsal stress fracture. Fifth metatarsal stress fractures can be treated conservatively or surgically, and excellent results have been reported for surgery with rapid recovery in athletes. Intramedullary screw fixation has become a popular form of fixation for fifth metatarsal stress fractures. Bone grafting presents the problems of a longer recovery time and additional skin incision for harvesting. The modified tension band wiring is an useful and simple option for surgical treatment of challenging fifth metatarsal stress fractures.

Treatment of a Chronic Gouty Ulcer on the Lateral Malleolus with Vacuum-Assisted Closure (VAC) Therapy

Gouty ulceration is a clinical manifestation of gout, which is a metabolic disease induced by disturbed purine metabolism. In general, protruded gout tophus and secondary infection made a gouty ulceration. It was generally treated with surgical debridement of the tophus and infected tissue. Inevitably, we make the skin defect if needed the wide surgical debridement. We waited for granulation tissue healing of the defect, then finished with a skin graft. However, larger sized gouty ulcerations require a longer period of healing time. We commonly used the vacuum assisted wound closer device (VAC) for shortening the healing time in diabetic foot ulceration. Use of VAC for a gouty ulceration was not nearly reported in literature. We report on the use of VAC after surgical debridement to heal a chronic gouty ulceration around the lateral malleolus.

Surgical Excision of Symptomatic Non United Fragment of Anterior Process Fractures of the Calcaneus / 대한스포츠의학회지

A fracture of the anterior process of the calcaneus has been considered unusual injury. A clinically missed diagnosis is often, that had gone on to non united fragment. Particularly if the patient has calcaneocuboid pain and disability, and that early excision of the fragment is usually advisable. There were 12 cases with performing the simple excision. The fracture characteristics were analyzed by Degan's classification; type 1 was 1case (8.3%), type 2 was 6 cases (50.0%) and type 3 was 5 cases (41.7%); and their morphology; elongation was 3 cases (50.0%) and fragmentation 3 cases (50.0%). And, the pre and post operative American Orthopedic Foot and Ankle Society midfoot score and visual analog scale was evaluated; 66.0 and 5.8 was significantly improved to 90.1 (p=0.007) and 2.2 (p=0.003), respectively. Postoperative Excellent and good satisfaction with possible return to previous sports activity was 10 cases (83.3%). Conclusively, simple excision of non united fragment of anterior process of the calcaneus is a successful clinical option.

Endoscopy versus Open Bursectomy of Lateral Malleolar Bursitis; Comparative Study / 대한족부족관절학회지

PURPOSE: To compare the result of endoscopic versus open bursectomy in lateral malleolar bursitis, which was not treated conservatively. MATERIALS AND METHODS: Between January 2008 and October 2009, We divided to two groups, endoscopy (group A) 11 cases, open bursectomy (group B) 11 cases. The average follow up period was 15 months (range, 12 to 18), the mean age was 66 (range, 38 to 79). We compared patients satisfaction, complete healing time, operation time, complications and recurrence. RESULTS: Group A had significant difference in terms of the clinical satisfactions, complete healing time. operation time, complications. Group A showed satisfaction (excellent 9, good 2), mean complete healing time 11.9 (8~14) days, operation time 37 (25~45) minutes, 1 case recur. Group B showed satisfaction (excellent 4, good 3, fair 1, poor 3), complete healing time 32.7 (14~98) days, operation time 22 (18~26) minutes. complication were one case of skin necrosis, one case of wound dehiscence, two cases of superficial peroneal nerve injury, no recurrence. Significant advantages of endoscopic method include lower morbidity and rapid wound healing period (p<0.05). CONCLUSION: Endoscopic resection of the lateral malleolar bursitis is a promising technique and shows favourable results compared to the open resection. Significant advantages of this method include lower morbidiy and rapid wound healing.

Sports Injury Surveillance during Summer Asian Games 2010 in Guangzhou / 대한스포츠의학회지

The purpose of this study was to do the surveillance study of sports injuries which were suffered to National players of South Korea Team during the summer Asian Games 2010 in Guangzhou. All medical staffs of Korea Delegation were asked to report all sports injuries newly incurred during the Games on injury report form, and the physicians made clinical diagnoses of the injuries. Total 725 injuries (430 athletes) were reported, and 288 injuries (209 athletes) were newly incurred: 68 injuries (58 athletes) were recurrent with previous history, resulting in total incidence rate: 45.5 injuries/1000 athlete exposures (AE) (95% confidence interval [CI]: 40.1-50.6 injuries/1000 AE) and incidence proportion: 26% (95% CI: 23-29). The new injury was highest in athletics (n=37, 12.8%), hockey (n=26, 9.0%), and basketball (n=23, 8.0%). While 162 injuries (56.2%) were incurred during practice, 126 injuries (43.8%) were incurred in competition. The most frequent diagnoses were lateral ankle ligament sprain (n=28, 9.7%, 95% CI: 6.3-13.1), calf muscle cramp (n=23, 95% CI: 4.9-11.1), and hamstring strain (n=22, 95% CI: 4.6-10.7). The relapsed injury was highest in athletics (n=16, 23.5%), basketball (n=6, 8.8%), and wrestling (n=5, 7.4%). While 50 injuries (73.5%) were recurred during practice, 18 injuries (26.5%) were recurred in competition. The most frequent diagnoses of relapsed injury were calf muscle cramp (n=11, 16.2%, 95% CI: 7.4-25.0), low back strain (n=6, 8.8%, 95% CI: 2.1-15.6), and hamstring strain (n=6, 8.8%, 95% CI: 2.1-15.6). Our data indicated incidence rates, incidence proportions, characteristics and frequent diagnoses of acute and recurrent sports injuries during the games, therefore these results could provide relevant information for the sports injury prevention at elite level.

Surgical Excision of Symptomatic Nonunion of Fifth Metatarsal Base Avulsion Fracture in Athletes / 대한스포츠의학회지

The purpose of this study was to evaluate the clinical results of surgical excision of symptomatic nonunion of fifth metatarsal base avulsion fracture in athletes. From February 2008 to December 2009, six athletic patients who had a symptomatic nonunion of fifth metatarsal base avulsion fracture underwent surgical excision of ununited bony fragment and they were followed for more than 12 months. The mean age was 18.5 years and the mean follow-up period was 13 months. The clinical results were evaluated using the American Orthopedic Foot and Ankle Society (AOFAS) forefoot scoring system and Visual Analogue Scale (VAS) scoring system and statistically analyzed (SPSS ver. 18.0). The AOFAS and VAS score was improved in all patients. The mean AOFAS forefoot score was improved from 58.6+/-5.7 preoperatively to 95+/-5.4 postoperatively, which indicated significant difference (p=0.024). The mean preoperative VAS score was 8.0+/-0.6 and the mean postoperative VAS score was 1.6+/-0.5 cm, which indicated significant difference (p=0.023). There were no postoperative problems and functional loss on the operation lesions. The surgical excision of symptomatic nonunion of fifth metatarsal base avulsion fracture in athletes was found to be one of the ideal treatment option for early return to full activity and relief of pain.

End Stage Ankle Arthritis with Ankle Instability Patients Treatment Results Using Autograft Ligament Reconstruction with Total Ankle Arthroplasty / 대한족부족관절학회지

PURPOSE: We report the clinical and radiographic result of ligament reconstruction using plantaris and total ankle replacement in end-stage ankle arthritis with ankle instability. MATERIALS AND METHODS: The study is based on the 9 cases among total 48 patients of end-stage ankle arthritis that were treated with total ankle prosthesis and ligament reconstruction from 2007 to 2009 at least 12 months follow-up. We evaluated the VAS (Visual analogue scale) pain score, AOFAS (American orthopedic foot and ankle society) score and radiographic measurements. RESULTS: Average age was 59.4 years (53~67 years) old. VAS pain score improved from preoperative average 8.2+/-0.9 (range, 7~10) to 2.7+/-1.7 (range, 0~6) and the AOFAS score improved from 46.4+/-14.6 points (range, 23~69) to 80.1+/-9.3 points (range, 65~95) at final follow-up. Anterior draw test improved 15.2+/-3.4 mm (range, 12~23 mm) to 8.8+/-2.6 mm (range, 6~13mm),varus stress test improved from 13.9+/-4.6degrees (range,10-18degrees) to 6.2+/-4.7degrees (range,2-18degrees) at final follow up. CONCLUSION: Plantaris ligament reconstruction is good option as part of the management of ankle instability with end-stage ankle arthritis. We achieved good clinical and radiographic results.

Common Foot and Ankle Disease

Participation of the population in sports activity is increasing. The life expectancy is also on the rise. In addition, the average initial age of women who wear heels is decreasing. For this reason, the incidence of foot disease such as ankle instability, foot deformity, and degenerative joint disease is becoming increasingly common. There is a wide spectrum of foot disease. Common foot disease that can be treated from outpatient base will be discussed in this review.

Chronic Lateral Ankle Instability: Efficacy of Combination of Ankle Arthroscopic Exploration and Modified Brostrom Operation / 대한족부족관절학회지

PURPOSE: To evaluate the efficacy of the arthroscopic exploration combined with modified Brostrom operation (MBO) for the treatment of chronic lateral ankle instability (CAI). MATERIALS AND METHODS: Sixty patients who diagnosed a CAI were performed MBO. We divided to 2 groups, whether simultaneously inspected by arthroscopy (group B) or not (group A). The both group's results were compared according to American Orthopedic Foot and Ankle Society Ankle-hindfoot score (AOFAS), functional ankle score and visual analog scale (VAS) at preoperative and final follow-up period. RESULTS: There were no significant differences of AOFAS, functional ankle score and VAS between both groups at final follow-up. However, in group A, 2 cases associated with medial ankle instability and syndesmotic injuries were did not diagnosed preoperatively, showed poor prognosis. In group B, one case had a permanent peroneal nerve symptom. The match rate of intra-articular lesions between preoperative diagnosis and postoperative arthroscopic diagnosis was 30% in group B. CONCLUSION: Combination of arthroscopic exploration and MBO is effective strategy for intra-operatively discrimination of intra-articular associated lesions for CAI.