Clinical significance of posterior talofibular ligament injury in chronic lateral ankle instability.

PURPOSE: Although arthroscopic repair of the anterior talofibular ligament (ATFL) is widely performed, the effect of posterior talofibular ligament (PTFL) injury on clinical outcomes remains unclear. This study aimed to evaluate the magnetic resonance imaging (MRI) findings of the PTFL in chronic lateral ankle instability (CLAI) and determine whether the presence or absence of PTFL injury affected the postoperative outcomes of arthroscopic ATFL repair. MATERIALS AND METHODS: Forty ankles of 35 patients who underwent arthroscopic repair for CLAI were included in this study as the experimental group, together with 25 ankles of 24 patients without CLAI as the control group. The PTFL thickness (PTFLT) and PTFL cross-sectional area (PTFLCSA) were measured using MRI and compared between the control and CLAI groups. The clinical outcomes of arthroscopic repair were compared between ankles with and without PTFL injuries. RESULTS: The mean PTFLT and PTFLCSA values were significantly higher in the CLAI group than in the control group. The PTFLT and PTFLCSA in the PTFL injury group were significantly larger than those in the non-injury group in the CLAI group. Postoperatively, there were no significant differences in clinical scores and talar tilt angles on stress radiographs between ankles with and without PTFL injury; however, instability recurrence was frequently observed in ankles with PTFL injury (32.1%) compared to the ankles without PTFL injury (16.7%). Poor-quality ATFL remnant, ATFL inferior fascicle, and calcaneofibular ligament injuries were frequently observed in ankles with PTFL injuries. CONCLUSIONS: Our findings indicate that PTFL injury is highly associated with CLAI but it does not affect postoperative clinical scores. However, postoperative instability recurrence was more often observed in ankles with PTFL injuries, given that they frequently have poor-quality ATFL remnants and CFL injuries. EVIDENCE LEVEL: Level III.

Effects of Preoperative Abnormality of Posterior Tibial Tendon on the Surgical Outcomes of Medial Osteochondral Lesion of the Talus.

BACKGROUND: Although surgical treatment for osteochondral lesion of the talus (OLT) can obtain good clinical outcomes, the rate of return to sports is variable. It is reported that medial OLT unrelated to trauma has abnormal structures in the medial aspect, which may induce the medial OLT due to the medial instability. The posterior tibial tendon (PTT) plays an important role in the stabilization of the foot, and high mechanical stress may be added to the PTT to compensate for medial instability in medial OLT. We investigated whether abnormal PTT findings on preoperative magnetic resonance imaging (MRI) in patients with OLT affect clinical outcomes after surgery.  Methods: Eighty-one ankles in 74 patients who were treated surgically for OLT were included in this study (41 men and 33 women; mean age, 26.0 years). Abnormalities of the PTT were evaluated using preoperative MRI. The Japanese Society for Surgery of the Foot (JSSF) scale, arch height, and ankle activity score (AAS) on standing plain radiogram were compared between patients with and those without preoperative PTT abnormalities. RESULTS: Twenty-five ankles (30.9%) had PTT abnormalities on preoperative MRI. All patients with preoperative PTT abnormalities were medial OLT. There were no significant differences in the preoperative JSSF scale in the procedures for OLT. The postoperative JSSF scale and arch height were significantly lower in patients with preoperative PTT abnormalities than those without them. AAS in patients with preoperative abnormalities significantly decreased at the final follow-up.  Conclusion: PTT abnormalities on preoperative MRI may affect clinical outcomes even in preoperative asymptomatic patients in the medial OLT unrelated to trauma.

Effect of a compression staple on correction of varus deformity during arthroscopic ankle arthrodesis.

BACKGROUND: Arthroscopic ankle arthrodesis (AAA) has become popular because of its higher rate of bone union, lower invasiveness, and shorter hospital stays compared to those of open arthrodesis. However, postoperative malalignment is often observed for severe varus deformity, which can cause nonunion, pain, and adjacent joint arthrosis. A compression staple can provide a persistent, strong compressive force on the bone surface. This study aimed to clarify the difference in alignment correction in AAA by comparing a compression staple and screws fixation with screws-only fixation pre- and postoperatively. METHODS: Seventy ankles in 67 patients undergoing AAA were retrospectively reviewed. AAA with three screws through the distal tibia was performed in 53 ankles, and 17 ankles underwent AAA with a compression staple and two screws. After the preparation of the joint surface arthroscopically, patients in the S group had three canulated cancellous screws inserted through the medial tibia. Patients in the CS group had a compression staple placed at the lateral aspect of the tibiotalar joint and two screws inserted through the medial side. Clinical scores and pre-and postoperative alignment on plain radiographs were compared between the two procedures. RESULTS: There were no significant differences in the pre-and postoperative Japanese Society for Surgery of the Foot scale. One ankle in the S group exhibited nonunion. There were no significant differences in talar tilt and tibiotalar angles between the groups. The tibial plafond angle in the CS group was significantly lower than that in the S group (p < 0.05). Postoperatively, talar tilt and tibiotalar angles on the coronal image, and the lateral tibiotalar angle in the CS group were significantly lower than those in the S group (p < 0.05). CONCLUSION: AAA with a compression staple and two-screw fixations could obtain more optimal alignments than AAA with screw-only fixation, even in cases with severe varus deformity.

Development of osteophytes and joint space narrowing is associated with cartilage degeneration of the osteochondral fragment in the osteochondral lesion of the talus.

BACKGROUND: During surgery for osteochondral lesions of the talus (OLT), preservation or excision of the osteochondral fragment is chosen based on the cartilage condition which influences the indication and clinical outcomes of surgical treatments. However, it is difficult to predict arthroscopic and histological findings of the cartilage on osteochondral fragments by radiographic evaluation. We focused on osteoarthritis (OA) changes on plain radiographs to predict the cartilage condition of the OLT. This study aimed to evaluate whether OA changes, including osteophyte and joint space narrowing, could predict arthroscopic and histological findings of the cartilage in OLT. METHODS: Seventy ankles with OLT were included in this study. Osteophytes and joint space narrowing were scored on plain radiographs. Lesion sizes were measured on computed tomography images. The cartilage surfaces of fragments were arthroscopically assessed using the International Cartilage Repair Society (ICRS) grade. Biopsy specimens from 32 ankles were histologically analyzed using the Mankin score. The relationships between OA scores, lesion size, ICRS grades, and Mankin score were analyzed. RESULTS: OA changes were frequently observed with increasing ICRS grades, especially in the medial tibiotalar joint. OA scores in patients with ICRS grade 1 were significantly lower than those in ICRS grades 2,3, and 4. The lesion sizes in patients with ICRS grade 3 and 4 were significantly smaller than those in patients with ICRS grade 1 and 2. Histological analysis showed increasing Mankin scores as the ICRS grade worsened. A mild correlation existed between the OA and Mankin scores (rs = 0.494). CONCLUSIONS: OA changes, such as osteophyte formation and joint space narrowing, are associated with arthroscopic findings of the articular surface and cartilage degeneration in osteochondral fragment in OLT. Articular cartilage conditions can be predicted by OA changes on plain radiographs, which is useful for choosing the appropriate treatment for patients with OLT. LEVEL OF EVIDENCE: Level Ⅳ, case series.

Lidocaine Tape Application for 3 Hours Prevents Vasovagal Syncope During Venipuncture: A Case Series.

Vasovagal syncope (VVS) or reflex is usually caused by physical and mental stress-related factors, like pain, anxiety, and fear, and it is one of the most frequent complications during dental treatment. Two patients, both with histories of dental phobia and of VVS during vaccination, venipuncture, and dental treatment with local anesthetics, were scheduled for dental treatment under intravenous (IV) sedation. However, both experienced episodes of VVS that occurred during venipuncture using a 24-gauge indwelling needle. We determined that pain was the main trigger of VVS for these patients and attempted to reduce venipuncture-associated pain using 60% lidocaine tape applied 3 hours before venipuncture at their next dental visits, respectively. Use of the lidocaine tape was successful and permitted comfortable placement of the IV catheter without any onset of VVS.

Evaluation of the flexion gap with a distal femoral trial component in posterior-stabilized total knee arthroplasty.

PURPOSE: A distal femoral trial component was manufactured, and flexion gap size and inclination were evaluated with or without the distal femoral trial component in total knee arthroplasty (TKA). This study aimed to evaluate the effect of the distal femoral trial component on flexion gap size and joint inclination in posterior-stabilized (PS)-TKA. MATERIALS AND METHODS: A total of 84 patients with medial osteoarthritis who underwent mobile-bearing PS-TKA using modified gap techniques were included in this retrospective study. The flexion gap size and inclination before and after setting the distal femoral trial component were evaluated and compared with the final gap size and inclination. RESULTS: The joint gap size and inclination were significantly lower in those with than in those without the distal femoral trial component (P = 0.005, P < 0.001). The final gap size and inclination were similar to the gap size and inclination with the distal trial component (P = 0.468, P = 0.158). CONCLUSIONS: The joint gap size and medial tension in PS-TKA were significantly reduced after setting the distal femoral trial component. The flexion gap measured using the distal femoral trial component was similar to that when the final trial component was set. To more accurately perform the gap technique TKA, the flexion gap should be measured using the distal femoral trial component.

Characteristic Bone Morphology Change of the Subtalar Joint in Severe Varus Ankle Osteoarthritis.

The subtalar joint has a possible compensatory mechanism for supramalleolar deformities; the failure of this mechanism causes the progression of ankle osteoarthritis. However, the reason for this failure has not been fully elucidated. This study aimed to evaluate the characteristics of the morphologic changes in the subtalar joint in varus ankle osteoarthritis using computed tomography. The study included 30 patients with severe osteoarthritis (modified Kellgren-Lawrence classification grade ≥ 3; mean age: 68.5 years) and 30 patients without- or with early osteoarthritis (grade 0-1; mean age: 43.0 years) as the control group. The location of cysts, osteophyte formation in the subtalar joint, and thickness of the subchondral bone plate were evaluated. In the osteoarthritis group, cyst formation was observed on the posterolateral side of the posterior facet of the calcaneus in 6 cases (20%) and of the talus in 7 cases (23.3%). Osteophyte formation was observed in the talus in 21 cases (70.0%) and in the calcaneus in 29 cases (96.6%). Osteophyte formation was observed on the posterior or lateral side of the posterior facet, and osteophyte contact between the talus and calcaneus was observed. The subchondral bone plate of the posterior medial side of the posterior facet of the talus was significantly thicker in the osteoarthritis group. The subtalar joint is less affected in severe varus ankle osteoarthritis containing a thickened subchondral bone plate in the posteromedial aspect of the posterior talar facet.

IV ATP potentiates midazolam sedation as assessed by bispectral index.

In this study, by measuring bispectral index (BIS), we tested the hypothesis that intravenous adenosine 5'-triphosphate (ATP) infusion would deepen the level of midazolam-induced sedation. Ten healthy volunteers underwent 2 experiments with at least 2 weeks' interval: immediately after intravenous bolus administration of midazolam (0.04 mg/kg), they received continuous infusion of either ATP infusion (100 µg/kg/min) or placebo (saline) for 40 minutes in a double-blind, randomized, crossover manner. Changes in BIS values and responsiveness to verbal command as well as cardiorespiratory variables were observed throughout the study periods. Administration of midazolam alone reduced BIS value from control: 97 ± 1 to 68 ± 18 at 25 minutes, which was accompanied by significant cardiopulmonary depressant effects, while maintaining responsiveness to verbal command (consciousness) throughout the study period. Coadministration of ATP with midazolam further reduced BIS value to 51 ± 13, associated with complete loss of consciousness without adverse effect on the cardiorespiratory systems. We conclude that the addition of ATP infusion to midazolam significantly enhances midazolam sedation without disturbing cardiorespiratory functions.

The characteristics of intravenous adenosine-induced antinociception in a rabbit model of acute nociceptive pain: a comparative study with remifentanil.

BACKGROUND: Adenosine and remifentanil are potent IV analgesics with ultrashort half-lives. The antinociceptive effect of IV adenosine has not been clearly characterized. We compared the antinociceptive effects of adenosine and remifentanil in rabbits. METHODS: Sixteen rabbits, placed on a sling allowing reasonably free movement, received IV adenosine (400 microg x kg(-1) x min(-1)) or remifentanil (0.4 microg x kg(-1) x min(-1)) over 240 min. RESULTS: Both drugs produced profound antinociception, as assessed by the number of animals unresponsive to clamping the forepaw and the electrical stimulation threshold of escape movement. With remifentanil, the antinociceptive effect increased rapidly, reaching its peak at 60 min, and then began to decline despite continued infusion. After stopping the infusion, it decreased rapidly and disappeared within 30 min. The vasodilating effect of IV adenosine was immediate in onset and ultrashort in duration. The antinociceptive effect of adenosine increased slowly but progressively during the infusion, reaching its peak only when the infusion ended. Then it decreased slowly over the following 360 min after terminating the infusion. CONCLUSION: Remifentanil had a rapid onset and short duration of action, and probably showed signs of tolerance development, whereas the antinocieptive effect of adenosine was slow in onset and long-lasting, despite its ultrashort plasma half-life and the immediate on-off profiles of its vasodilating effect.