High-stress distribution in the lateral region of the subtalar joint in the patient with chronic lateral ankle instability

Hounsfield Unit values on the subchondral bone are related to clinical outcomes in bone marrow stimulation for osteochondral lesions of the talus

BACKGROUND

Poor clinical outcomes in bone marrow stimulation (BMS) for the osteochondral lesion of the talus (OLT) are caused by subchondral bone deterioration. It is reported that microfracture induces endochondral ossification in the subchondral bone, which may affect the subchondral bone condition after BMS. This study analyzed osteosclerotic patterns of the bed in OLTs on computed tomography (CT) images and the relationship between the subchondral bone condition and clinical outcomes of BMS.

METHODS

Sixty-nine ankles in 61 patients with OLT were included. Hounsfield unit (HU) on the bed of OLTs was measured on CT images and the pattern of osteosclerosis or absorption in the bed was analyzed. In these patients, 25 ankles in 24 patients underwent BMS. They were divided into 2 groups according to the presence of bone marrow edema (BME) one year after surgery, and clinical outcomes were compared.

RESULTS

HUs in the anterior region were significantly higher than those of other areas. In patients with BMS, the JSSF scale for BME positive group (88.0 ± 7.7 points) was significantly lower than that for BME negative group (95.0 ± 6.1 points) (p < 0.05) at the final follow-up. On preoperative CT images, HU values of the central region in the BME-positive group were significantly lower than those in the BME-negative group (p < 0.05).

CONCLUSION

Osteosclerotic changes in the anterior part of the bed were frequently observed, and BMS for the area with low HU values decreased clinical outcomes. BMS should be performed with attention to subchondral bone condition to obtain good clinical outcomes.

LEVEL OF EVIDENCE

4, case series.

The Relationship Between Calcaneofibular Ligament Injury and Ankle Osteoarthritis Progression: A Comprehensive Analysis of Stress Distribution and Osteophyte Formation in the Subtalar Joint

BACKGROUND

Ankle osteoarthritis (OA) mainly arises from trauma, particularly lateral ligament injuries. Among lateral ligament injuries, ankles with calcaneofibular ligament (CFL) injuries exhibit increased instability and can be a risk factor ankle OA progression. However, the relationship between CFL injury and OA progression remains unclear. Therefore, this study aims to assess the relationship between CFL injuries and ankle OA by investigating stress changes and osteophyte formation in subtalar joint.

METHODS

We retrospectively reviewed the magnetic resonance imaging (MRI) and plain radiographic evaluations of 100 ankles of 91 patients presenting with chronic ankle instability (CAI), ankle OA, or other ankle conditions. The association between CFL injuries on the oblique view of MRI and the severity of ankle OA (based on Takakura-Tanaka classification) was statistically evaluated. Additionally, 71 ankles were further subjected to CT evaluation to determine the association between the CFL injuries and the Hounsfield unit (HU) ratios of the subtalar joint and medial gutter, and the correlation between the subtalar HU ratios and osteophyte severity were statistically evaluated.

RESULTS

CFL injury was observed in 35.9% (14/39) of patients with stage 0, 42.9% (9/21) with stage 1, 50.0% (10/20) with stage 2, 100% (9/9) with stage 3a, and 90.9% (10/11) with stage 3b. CFL-injured ankles exhibited higher HU ratios in the medial gutter and lower ratios in the medial posterior subtalar joint compared to uninjured ankles. A negative correlation was observed between medial osteophyte severity and the medial subtalar joint HU ratio.

CONCLUSION

Our findings suggest that CFL injuries are common in severe ankle OA impairing the compensatory function of the subtalar joint through abnormal stress distribution and osteophyte formation.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Relationship between pain and intra-articular pathology in patients with chronic lateral ankle instability

PURPOSE

Repeated ankle sprains can lead to chronic lateral ankle instability (CLAI). It is unclear whether CLAI causes pain unless complicated by intra-articular lesions. This study aimed to analyze the characteristics of pain and the relationship between pain and intra-articular pathology in patients with CLAI.

MATERIALS AND METHODS

Fifty-three ankles in 46 patients with CLAI who had undergone surgery were retrospectively reviewed. The self-administered foot evaluation questionnaire (SAFE-Q) was given to patients the day before surgery. Intra-articular lesions were assessed using arthroscopy and magnetic resonance imaging (MRI). In addition, the Hounsfield Unit (HU) on computed tomography (CT) of the medial gutter was measured. The relationship between pain and intra-articular findings was also analyzed.

RESULTS

The pain and pain-related scores in the SAFE-Q were significantly correlated with synovitis in 96.3% (rs = - 0.532). HU ratios in the tibia and talus were also significantly correlated with pain (rs = - 0.603, - 0.534, respectively). The arthroscopic synovitis score and HU ratios in patients with high pain scores were significantly higher than those in patients with low pain scores. Forty ankles (75.5%) had synovitis and articular cartilage injuries were observed in 22 ankles (41.5%). Patients with fluid collection or bone marrow lesions (BML) scored significantly lower in pain than those without, but there was no significant difference between patients with and without cartilage injury. Multiple regression analysis revealed that a high synovitis score and HU ratio of the talus were significantly associated with high pain.

CONCLUSIONS

Intra-articular lesions such as synovitis and BML were associated with pain in patients with CLAI. Osteosclerotic changes in the medial gutter also induced ankle pain, indicating that osteoarthritic changes had already begun. Therefore, lateral ankle ligament injuries after ankle sprain should be appropriately treated to avoid secondary degenerative changes.

LEVEL OF EVIDENCE: 4

Loosening of the anterolateral capsule affects the stability after arthroscopic lateral ankle ligament repair of chronic ankle instability

PURPOSE

Arthroscopic anterior talofibular ligament (ATFL) repair for chronic lateral ankle instability (CLAI) has been widely performed. The recurrence of the instability after the surgery sometimes occurs, which may cause the development of osteoarthritis. Therefore, it is important to elucidate the factors of the recurrence. This study aimed to evaluate the loosening of the capsule in the MRI and whether it affected clinical outcomes or not in arthroscopic ATFL repair.

MATERIALS AND METHODS

Thirty-eight ankles in 35 patients with CLAI treated by arthroscopic lateral ligament repair were included. The capsule protrusion area defined as the area that protruded ATFL laterally from the line connecting the fibula and talus attachment on MRI was measured. Capsule protrusion area in ankles with or without CLAI was compared and the relationships between it and clinical outcomes were assessed.

RESULTS

The capsule protrusion area in the CLAI group (74.2 ± 36.4 mm2) was significantly larger than that in the control (25.5 ± 14.3 mm2) (p < 0.01). The capsule protrusion area in the poor remnant group (93.8 ± 36.4 mm2) was significantly larger than that in the excellent (53.2 ± 40.3 mm2) (p < 0.05). The capsule protrusion area in the patients with recurrent instability (99.8 ± 35.2 mm2) was significantly larger than that without recurrent instability (62.4 ± 30.9 mm2) (p < 0.01). Clinical scores in the recurrent group were significantly lower than those in the non-recurrent group (p < 0.05).

CONCLUSIONS

Capsule loosening would be one of the causes of the recurrence of instability after arthroscopic lateral ankle ligament repair. Evaluation of the capsule protrusion area on MRI is helpful to choose appropriate surgical procedures for CLAI patients.

LEVEL OF EVIDENCE: 4

Risk Factors for the Recurrence of Instability After Lateral Ankle Ligament Repair

BACKGROUND

Arthroscopic anterior talofibular ligament (ATFL) repair is widely performed for chronic lateral ankle instability (CLAI). Although many studies have reported excellent outcomes with this procedure, the recurrence of instability remains a common concern. Therefore, this study aimed to analyze the risk factors for the recurrence of instability after arthroscopic repair for CLAI.

METHODS

Fifty-six ankles of 53 patients with a mean age of 31.8 ± 14.7 years were retrospectively reviewed. All patients underwent arthroscopic ATFL repair. If instability remained immediately after ATFL repair, calcaneofibular ligament (CFL) repair was performed. The Ankle Activity Score (AAS) was assessed preoperatively, and clinical outcomes including the Japanese Society for Surgery of the Foot scale, Karlsson-Peterson scores, and the Self-Administered Foot Evaluation Questionnaire (SAFE-Q) were evaluated preoperatively and at the final follow-up. Talar tilt angle (TTA) was assessed preoperatively and 1 year postoperatively. Ankles were divided into 2 groups-nonrecurrence (postoperative TTA, <6 degrees) and recurrence (postoperative TTA, ≥6 degrees)-and clinical outcomes were compared.

RESULTS

Sixteen ankles showed recurrent instability, whereas 40 did not. AAS, TTA, and social functioning in the SAFE-Q were significantly higher in the recurrence group than those in the nonrecurrence group preoperatively. In addition, the rate of poor ATFL remnant quality and the number of CFLs not repaired despite the preoperative injury diagnosis were significantly higher in the recurrence group than in the nonrecurrence group.

CONCLUSION

Arthroscopic repair for ATFL and CFL deficiencies with preoperative high activity, poor remnant quality, and neglected CFL injury can result in the recurrence of instability. Appropriate surgical procedures to prevent the recurrence of instability should be selected for these ankles.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Pure ligamentous ankle dislocation: A case report

INTRODUCTION AND IMPORTANCE

Pure ankle dislocation is a rare injury, and this injury is an orthopedic emergency requiring immediate reduction. In more common circumstances, this injury is usually associated with malleolar fractures. The standardized treatment protocol is still deficient.

CASE PRESENTATION

We report a case of a 33-year-old woman who presented with an open ankle dislocation without concomitant malleolar fractures. Early extensive wound debridement, immediate reduction, and immobilization of the ankle joint using an external fixator were performed during the first surgery. During the second surgery, which was performed 3 weeks later, the medial and lateral ankle ligaments were repaired, and a suture tape internal brace was added. A good functional outcome with the American Foot and Ankle Society score of 87 was achieved at 1-year follow-up.

DISCUSSION

In an open dislocation with massive ligamentous injury, staged surgery could be performed to prevent deep infection, with extensive debridement and immobilization using an external fixator in the first stage and ligament repair in the second stage. An internal brace using a suture tape is an option for ligament repair if the remnant is not sufficient to be repaired, as in this case. Early range of motion exercises should be initiated after second-stage surgery to prevent stiffness.

CONCLUSION

Staged surgery using an external fixator and ligament repair using a suture tape and internal brace augmentation can be an effective option for a pure ligamentous ankle dislocation with an open wound and a poor remnant of ankle ligaments.

Surgical outcome of avulsion fractures of the distal fibula: a systematic literature review

PURPOSE

To provide a systematic overview of clinical and radiographic outcomes in patients who underwent surgical treatment of a painful avulsion fragment of the distal fibula also known as posttraumatic os subfibulare.

METHODS

A systematic literature search across two major sources (PubMed and Scopus) was performed. Twenty-seven studies were included and analyzed using the modified Coleman score to assess the methodologic quality.

RESULTS

The surgical treatment of symptomatic os subfibulare, with or without concomitant ankle instability, generally results in substantial improvement in clinical and radiographic outcomes with relative low complication rates. Clinical outcome measures may not be affected by the presence of ankle instability or by the fragment size. The methodological quality of analyzed studies was satisfactory.

CONCLUSION

Posttraumatic os subfibulare may result in chronic pain and ankle instability. If surgery is indicated, ankle instability should be concomitantly addressed when present. Based on available literature, satisfactory postoperative outcomes can be reliably expected following surgical treatment.

LEVEL OF EVIDENCE

Systematic Review of Level III and Level IV Studies, Level IV.

Distributional patterns of subchondral bone density and histopathological features of the first tarsometatarsal joint in hallux valgus feet

Background

Hypermobility of the first tarsometatarsal (TMT) joint is frequently identified in patients with hallux valgus (HV); however, its association with the development of osteoarthritis in the first TMT joint in such patients remains unknown. The purpose of this study was to clarify the distribution of subchondral bone density of the first TMT joint via computed tomography (CT) using Hounsfield units (HU).

Methods

Patients were divided into three groups: the osteotomy (20 feet; 20 women, mean age: 61.8 years), arthrodesis (23 feet; two men, 21 women, 71.2 years), and control group (patients without HV deformity who had undergone CT scans of the foot; 13 feet; seven men, six women, 29.7 years). The HU ratios were calculated, which were defined as the HU value of each subdivision of the subarticular spongiosa of the first TMT joint [dorsomedial (DM), dorsolateral (DL), plantomedial (PM), and plantolateral (PL)] divided by the HU values of the entire joint surface. The ratios for the osteotomy, arthrodesis, and control groups were compared. The degradation of the articular cartilage in the first TMT joint was histologically graded in the arthrodesis group. Tukey–Kramer multiple comparison analysis was conducted to compare the HU ratios among the three groups, and the histological grade in each subdivision.

Results

The arthrodesis group demonstrated high HU ratios in the DM area of the medial cuneiform, and significantly lower HU ratios in the PL area of the first metatarsal. Lower HU ratios in the DL area were observed in both the osteotomy and the arthrodesis group when compared to that in the medial cuneiform of the control group. The histological evaluation indicated nearly normal articular cartilage for all subdivided areas in both the medial cuneiform and the first metatarsal in patients with severe HV.

Conclusions

Although high subchondral bone density was identified in the DM area of the medial cuneiform in severe HV, only mild degradation was histologically observed in the articular cartilage of the first TMT joint. Our findings suggest that the indications for arthrodesis of the first TMT should be reconsidered based on the severity of the degenerative changes in the first TMT joint.