Ki Won Young

Perioperative complications of the MOBILITY total ankle system: comparison with the HINTEGRA total ankle system

BackgroundThe perioperative complications associated with MOBILITY total ankle replacement arthroplasty have not yet been reported.MethodsDuring the research period from May 2008 to June 2009, a total of 30 consecutive cases of ankle arthritis were treated with surgery. An investigation into the perioperative complications for these cases was conducted. Comparison with the previously reported perioperative complications for the HINTEGRA model was made. The 30 cases were divided into two groups wherein the first group underwent surgery during the early half of the study period and the second group underwent surgery during the later half. The incidences of complications between the two groups were then compared.ResultsThere was no difference in the incidence of perioperative complications between the use of the HINTEGRA model and the MOBILITY model for total ankle replacement arthroplasty, although medial malleolar fracture was statistically increased with the use of MOBILITY.ConclusionsThe study implies that a new learning curve may affect the outcome of surgery when a newly designed implant is used for total ankle replacement arthroplasty and that long tibial procedure time and long distraction time played a critical role in the incidence of malleolar fracture.

A New Measure of Tibial Sesamoid Position in Hallux Valgus in Relation to the Coronal Rotation of the First Metatarsal in CT Scans

Background: We aimed to find a new radiographic measurement for evaluating first metatarsal pronation and sesamoid position in hallux valgus (HV) deformity. Methods: Data from a clinical study of 19 control patients (19 feet) with no HV deformity were compared with preoperative data of 138 patients (166 feet) with HV deformities. Using a weightbearing plain radiograph in anteroposterior (AP) view, the intermetatarsal angles (IMAs) and the hallux valgus angles (HVAs) of the control and study groups were measured. Using a semi-weightbearing coronal computed tomography (CT) axial view, the α angle was measured in the control and study groups. In addition, the tibial sesamoid grades in plain radiograph tangential view and the CT axial view were measured. The tibial sesamoid position in an AP view was checked preoperatively. Based on these measurements, 4 types of HV deformities were defined. Results: The mean values of the α angle in the control and HV deformity groups (control group µ = 13.8 degrees, study group µ = 21.9 degrees) was significantly different. Among 166 HV feet, 145 feet (87.3%) had an α angle of more than 15.8 degrees, which is the upper value of the 95% confidence interval of the control group, indicating the existence of abnormal first metatarsal pronation in HV deformity. Four types of HV deformities were defined based on their α angles and tibial sesamoid grades in CT axial view (CT 4 position). Among 25.9% (43/166) of the study group, abnormal first metatarsal pronation with an absence of sesamoid deviation from its articular facet was observed. The prominent characteristic of this group was that they had high grades in the AP 7 position (≥5); however, in the CT 4 position, their grade was 0. This group was defined as the “pseudo-sesamoid subluxation” group. Conclusions: Patients with HV deformities had a more pronated first metatarsal than the control group, with a greater α angle. Pseudo-subluxation of the sesamoids existed in 25.9% of our study group. From our results, we suggest that the use of the CT axial view in assessments of HV deformity may benefit surgeons when they make operative choices to correct these deformities. With regard to the pseudo-sesamoid subluxation group, the use of the distal soft tissue procedure is not surgically recommended. Level of Evidence: Level III, retrospective comparative study.

Medial approaches to osteochondral lesion of the talus without medial malleolar osteotomy

The purpose of this study was to determine the area of the talus that can be reached through combined anterior and posterior arthrotomy without medial malleolar osteotomy. Five fresh-frozen cadaver foot-ankle specimens were examined using posteromedial approach and anteromedial approach. We calculated the size of the marked area beginning from the posteromedial corner of the talus in the posteromedial approach and beginning from the anteromedial corner in the anteromedial approach. From the posteromedial talus, we can access 33% of the talus’ AP length and 30% of its medial to lateral length through a posteromedial approach. From the anteromedial arthrotomy, 50% of the AP length and 31% of the medial to lateral length can be reached. This leaves approximately 20% that is not accessible. If the osteochondral lesion is within the accessible area through either a posteromedial or anteromedial approach as viewed on MRI/CT, it can be safely reached without a medial malleolar osteotomy.

Mobility changes of the first ray after hallux valgus surgery: clinical results after proximal metatarsal chevron osteotomy and distal soft tissue procedure.

Background: The purpose of this study was to evaluate the change of the first ray mobility after PMCO and DSTP in hallux valgus patients. Materials and Methods: From May 2004 to December 2005, 82 PMCO with DSTP surgeries were performed for the management of hallux valgus deformity. The dorsiflexion mobility of the first ray of the foot was measured both preoperatively and 1 year after surgery using a modified Klaue device. The data were statistically analyzed with a paired t-test. An American Orthopedic Foot and Ankle Society (AOFAS) forefoot hallux score and patient satisfaction were also evaluated. Results: Subjects consisted of 9 male and 73 female patients with an average age of 47.7 years (range, 19 to 74 years). The mean preoperative dorsiflexion mobility was 6.8 (range, 2.32 to 15.02) mm and the mean dorsiflexion mobility at one year after operation was 3.2 (range, from 1.7 to 5.4) mm. This decrease was statistically significant (p < 0.01). The mean preoperative AOFAS forefoot hallux score was 66.2 (range, 44 to 90) and improved to 89.1 (range, 72 to 100) by the 1-year followup (p < 0.01). Conclusion: Clinically, the dorsiflexion mobility of the first ray was significantly reduced after correction of hallux valgus with PMCO with DSTP. Because the stability of the first ray can be improved with PMCO with DSTP, the surgical indication for this procedure could include some patients showing hypermobility of the first ray.

The Plantar Gap Another Prognostic Factor for Fifth Metatarsal Stress Fracture

Background: There have been diverse results, even in the same Torg type classification, in cases with fifth metatarsal stress fracture. Hypothesis: The “plantar gap” is correlated with the time for bone union and complications. It might be used for a prognostic factor. Study Design: Cohort study; Level of evidence, 3. Methods: Seventy-five cases with a fifth metatarsal stress fracture treated with modified tension band wiring from January 2003 to December 2008 were evaluated retrospectively. This consecutive series of patients included 71 male and 2 female patients with a mean of 19.8 years of age at the time of surgery. All of the enrolled patients were elite-level athletes. Each case was classified according to Torg classification and the degree of plantar gap was also measured. After the surgery, bone union was determined by computed tomography findings. Statistical analysis of the Torg classification and time for bone union, as well as plantar gap and time for bone union, was performed. Results: The mean time for bone union for each Torg type was 71.05 ± 21.77 days for type I, 104.48 ± 54.62 days for type II, and 122.92 ± 51.75 days for type III. There was a significant difference in the time for bone union among the 3 Torg types (P = .008). The mean time for bone union in group A (plantar gap <1 mm) was 71.21 ± 29.95 days and it was 126.4 ± 51.99 days for group B (plantar gap ≥1 mm) (significantly different; P < .001). In addition, there was a positive correlation of the time for bone union with the degree of plantar gap (ρ = .661, P < .001). In cases with Torg type II classification, there was a significant difference in the time for bone union between groups A and B (P < .001) In addition, there was a strong correlation between the time for bone union and the degree of plantar gap (ρ = .657, P < .001). There were 8 cases of nonunion in Torg type II, and 1 case in Torg III. With regard to the plantar gap, there was 1 case of nonunion in group A, and 8 cases in group B. Conclusion: The results of this study suggest that the plantar gap might be used for prognosis in cases with a fifth metatarsal stress fracture, even in patients with the same Torg classification.

Perioperative Complications and Learning Curve of the Mobility Total Ankle System

Background: Only 2 articles related to the recently developed Mobility Total Ankle System (Johnson & Johnson Medical/DePuy International, Leeds, UK) have been published to date. The purpose of this study was to determine the perioperative complications associated with the Mobility Total Ankle System and whether a learning curve exists for this system. Materials and Methods: We recruited 60 consecutive patients undergoing total ankle arthroplasty using the Mobility Total Ankle System for advanced osteoarthritis and rheumatoid arthritis between May 2008 and June 2010. Group A included the initial 30 patients who underwent surgery, and group B included the next 30 patients. Reporting of adverse perioperative events, including wound healing problems, fracture, aseptic loosening, tendinitis, component malposition, neuroma, and bony impingement, was limited to the first 3 months after the surgery. Results: Eleven of the 30 patients in group A developed complications (36.7%), and 1 died of an unknown cause 6 months after leaving the hospital. The complications in this group included medial malleolar fracture in 6 patients, lateral malleolar fracture in 1, wound healing problems in 2, and varus deformity in 2. Five of the 30 patients in group B developed complications (16.7%). The complications in this group included medial malleolar fracture in 1 patient, medial impingement in 2, Achilles tendon rupture in 1, and wound problems in 1. There was no statistically significant difference (P = .08) between the 2 groups in the incidence of complications after total ankle replacement arthroplasty. There was also no significant difference between the 2 groups in the types of complications seen. Conclusions: Perioperative complications associated with total ankle replacement arthroplasty using the Mobility Total Ankle System were seen in 16 of 60 patients. Group A had a higher incidence of perioperative complications than did group B. However, the difference was not statistically significant. Either the expertise of the surgeon or the simplicity of the total ankle system can affect the learning curve, although these things were not specifically quantified in this study. Level of Evidence: Level III, comparative case series.

Deltoid Ligament and Tibiofibular Syndesmosis Injury in Chronic Lateral Ankle Instability: Magnetic Resonance Imaging Evaluation at 3T and Comparison with Arthroscopy

Objective To evaluate the prevalence of deltoid ligament and distal tibiofibular syndesmosis injury on 3T magnetic resonance imaging (MRI) in patients with chronic lateral ankle instability (CLAI). Materials and Methods Fifty patients (mean age, 35 years) who had undergone preoperative 3T MRI and surgical treatment for CLAI were enrolled. The prevalence of deltoid ligament and syndesmosis injury were assessed. The complexity of lateral collateral ligament complex (LCLC) injury was correlated with prevalence of deltoid or syndesmosis injuries. The diagnostic accuracy of ankle ligament imaging at 3T MRI was analyzed using arthroscopy as a reference standard. Results On MRI, deltoid ligament injury was identified in 18 (36%) patients as follows: superficial ligament alone, 9 (50%); deep ligament alone 2 (11%); and both ligaments 7 (39%). Syndesmosis abnormality was found in 21 (42%) patients as follows: anterior inferior tibiofibular ligament (AITFL) alone, 19 (90%); and AITFL and interosseous ligament, 2 (10%). There was no correlation between LCLC injury complexity and the prevalence of an accompanying deltoid or syndesmosis injury on both MRI and arthroscopic findings. MRI sensitivity and specificity for detection of deltoid ligament injury were 84% and 93.5%, and those for detection of syndesmosis injury were 91% and 100%, respectively. Conclusion Deltoid ligament or syndesmosis injuries were common in patients undergoing surgery for CLAI, regardless of the LCLC injury complexity. 3T MRI is helpful for the detection of all types of ankle ligament injury. Therefore, careful interpretation of pre-operative MRI is essential.

Long-Term Results of Neurectomy in the Treatment of Morton’s Neuroma More Than 10 Years’ Follow-up

Purpose. The objective of this retrospective study was to evaluate the long-term follow-up results of neurectomy clinical outcomes and complications in the treatment of Morton’s neuroma. Materials and methods. A total of 19 patients (19 different feet) were treated for Morton’s neuroma by excision of the interdigital nerve at our institute between May 1997 and May 1999. Thirteen (13 feet) of them were followed up. The 13 patients were female and had an average age of 43 years (range 34-54 years) at the time of the operation. The patients were followed-up for a mean of 10.5 years (range 10.0-12.2 years) and scored using the American Orthopaedic Foot & Ankle Society (AOFAS) forefoot scoring system and Visual Analogue Scale (VAS) score. Subjective satisfaction was evaluated at the final follow-up. Results. Eight patients scored more than 90 on the AOFAS forefoot scoring system. The VAS score was improved in all patients. The mean preoperative VAS score was 8.6 ± 0.8 cm (7-10) and the mean follow-up VAS score was 2.4 ± 1.8cm (0-6), which indicated no significant difference (P > .05). The final follow-up satisfaction results indicated that 4 patients were completely satisfied with the operation, 4 were satisfied with minor reservations, 5 were satisfied with major reservations, and no patient was unsatisfied. Neurectomy to treat Morton’s neuroma had a good satisfaction rate (61%). Eleven of the patients complained of numbness on the plantar aspect of the foot adjacent to the interspace, and 2 of these 11 patients complained of disability induced by severe numbness. There was a complaint of residual pain by 1 patient. There were no skin problems on the operation lesions. Conclusion. The long-term results of neurectomy clinical outcomes in Morton’s neuroma are slightly worse than the short- and mid-term results. Levels of Evidence: Therapeutic, Level IV, Retrospective case series

A Simpler Device for Measuring the Mobility of the First Ray of the Foot

Background: Since some devices can be cumbersome to use, we evaluated the validity and reliability of a specially designed device for easily checking the mobility of the first ray of the foot. Materials and Methods: To analyze the validity of the device, the dorsal mobility of the first ray of the foot was measured with the modified Coleman block test developed by Fritz et al., the Klaue device, and the custom device. Two-tailed Students paired t-test and Pearson correlation were used to compare the values of the two tests. For evaluation of inter- and intra observer reliability of the EMC device, 3 independent observers measured the dorsal mobility of the first ray of the foot twice. The results were analyzed with two-tailed Students paired t-test and ANOVA to evaluate intraobserver and interobserver reliability, respectively. Results: For both the first and second examinations of reliability, the difference between the two values was significant (p < 0.05) for the Coleman block test but not significant (p = 0.118) in comparison with the Klaue device. The measurements from both examinations showed good correlation (Pearson correlation coefficient: comparison with the Coleman block test = 0.84 (p < 0.05), with the Klaue device = 0.92 (p < 0.05)). The paired t-test for intraobserver validity showed no statistically significant difference among observers (p = 0.52, 0.58, 0.96, Pearson correlation coefficient = 0.76, 0.79, 0.80), and ANOVA testing for interobserver reliability showed no significant difference either (p = 0. 96, Pearson correlation coefficients = 0.83, 0.84, and 0.86, respectively). Conclusion: This study demonstrated that the EMC device is both reliable and valid for measuring the mobility of the first ray of the foot.

Comparison of MRI and arthroscopy after autologous chondrocyte implantation in patients with osteochondral lesion of the talus.

No reported postoperative evaluation method is accurately correlated with the clinical outcome of repaired cartilage after autologous chondrocyte implantation. This study investigated the correlation of follow-up magnetic resonance imaging (MRI) evaluation and arthroscopic findings to the clinical outcome of surgically repaired osteochondral lesion of the talus with autologous chondrocyte implantation using the modified magnetic resonance observation of cartilage repair tissue (MOCART) scoring system.The study group comprised 21 consecutive patients with an osteochondral lesion of the talus who underwent autologous chondrocyte implantation. One year postoperatively, a follow-up MRI was obtained and a second-look arthroscopy was performed. Although the arthroscopic findings of the repaired osteochondral lesion of the talus showed better correlation with the clinical outcome when used with the modified MOCART scoring system, the higher correlation occurred only within a statistical error range, thus making the correlation not significantly different from the one determined on MRI. Therefore, a second-look arthroscopy is not necessary to evaluate the repaired talar cartilage after an autologous chondrocyte implantation. Magnetic resonance imaging is a useful method for long-term follow-up of patients with osteochondral lesions of the talus.