Clinical outcomes after arthroscopic microfracture for osteochondral lesions of the talus are better in patients with decreased postoperative subchondral bone marrow edema.

PURPOSE: Magnetic resonance imaging (MRI) findings of subchondral bone marrow edema (SBME) in osteochondral lesions of the talus (OLT) after arthroscopic microfracture are associated with poor clinical outcomes. However, the relationship between SBME volume change and clinical outcomes has not been analyzed. It was hypothesized that clinical outcomes correlated with SBME volume change and extent of cartilage regeneration in patients with OLT. METHODS: 64 patients who underwent arthroscopic microfracture for OLT were followed up for more than 2 years. SBME volume change was measured by comparing preoperative and 2-year follow-up MRI. Clinical outcomes were assessed using the visual analogue scale (VAS) and the American orthopedic foot and ankle society ankle-hindfoot scale (AOFAS) at the 2-year and final follow-up. To compare clinical outcomes, patients were categorized into two groups: decreased SBME (DSBME) group (cases without SBME on either MRI or with a decreased SBME volume between the MRIs) and increased SBME (ISBME) group (cases with new SBME on postoperative MRI or with an increased SBME volume between the MRIs). Additionally, the effects of age, sex, body mass index, symptom duration, OLT size, OLT location, containment/uncontainment, preoperative subchondral cysts, pre- and postoperative SBME volumes, and MRI observation of cartilage repair tissue score on clinical outcomes were analyzed. RESULTS: The DSBME group included 45 patients, whereas the ISBME group included 19. The mean age was 40.1 ± 17.2 years, and mean follow-up period was 35.7 ± 18.3 months. Preoperative SBME volume was significantly higher in the DSBME group, while the ISBME group had higher volumes at the final follow-up. In both groups, the VAS and AOFAS scores significantly improved at the final follow-up (p < 0.001, < 0.001). The VAS scores were significantly lower in the DSBME group at the 2-year and final follow-up (p = 0.004, 0.011), while the AOFAS scores were significantly higher (p = 0.019, 0.028). Other factors including cartilage regeneration did not affect clinical outcomes. CONCLUSION: SBME volume change correlated with clinical outcomes after arthroscopic microfracture for OLT. Clinical outcomes were worse in patients with new postoperative SBME and increased postoperative SBME volume. In patients with an unsatisfactory clinical course that show decreased SBME via postoperative MRI, an extended follow-up in a conservative manner could be considered. LEVEL OF EVIDENCE: Level III.

The signal intensity of preoperative magnetic resonance imaging has predictive value for determining the arthroscopic reparability of the anterior talofibular ligament.

PURPOSE: Arthroscopic all-inside anterior talofibular ligament (ATFL) repair is a common surgical technique for chronic ankle instability (CAI), and the condition of the ATFL remnants is associated with its reparability. ATFL reparability can affect the clinical course, but the relationship between magnetic resonance imaging (MRI) findings and the intraoperative ATFL reparability is still unclear. The purpose of this study was to investigate the relationship between ATFL signal intensities according to MRI and intraoperative ATFL reparability. METHODS: This study included 55 cases of CAI (n = 37) and osteochondral lesion of the talus (n = 18) that underwent MRI followed by subsequent arthroscopy. MRI signal intensity was measured preoperatively to calculate the signal to noise ratio (SNR). During arthroscopy, the presence of an ATFL tear was checked and the ATFL tension was classified as taut, mild laxity, or laxity; ATFL quality was classified as excellent (normal), moderate (abnormal but reparable), or poor (irreparable). It was then analyzed whether there was a relationship between the intraoperative findings and the SNR. RESULTS: The mean SNR was 23.4 ± 21.6. The SNR was significantly different according to the presence of an ATFL tear and ATFL tension and quality (all P = 0.001). The SNR was better correlated with ATFL quality (r = 0.708) than the presence of a tear (r = 0.545) or degree of tension (r = 0.653). The diagnostic SNR cutoff point to distinguish a normal ATFL from an abnormal but reparable ATFL was 11.2, and that to distinguish between an irreparable and reparable ATFL, was 32.3. CONCLUSION: The SNR, representing MRI signal intensities, is highly correlated with the intraoperative measures of the ATFL. Therefore, the SNR had predictive value for determining the arthroscopic reparability of the ATFL. LEVEL OF EVIDENCE: Level III.

Hindfoot Alignment Change After Total Ankle Arthroplasty for Varus Osteoarthritis.

BACKGROUND: In patients with end-stage varus ankle osteoarthritis (OA), hindfoot varus malalignment resulting from the varus deformity of the ankle joint is common. Although total ankle arthroplasty (TAA) performed to correct varus deformity of the ankle joint has the effect of correcting hindfoot alignment, no reports to date have described how much hindfoot alignment correction can be achieved. The purpose of this study was to identify correlation between ankle deformity correction and hindfoot alignment change after performing TAA in patients with end-stage varus ankle OA. METHODS: A total of 61 cases that underwent TAA for end-stage varus ankle OA and followed up for at least 1 year were enrolled for this study. Correlation between changes of tibial-ankle surface angle (TAS), talar tilt (TT), and tibiotalar surface angle (TTS) and changes of hindfoot alignment angle (HA), hindfoot alignment ratio (HR), and hindfoot alignment distance (HD) measured preoperatively and at postoperative year 1 was analyzed. RESULTS: TAS, TT, and TTS changed from 83.9 ± 4.1 degrees, 5.8 ± 5.0 degrees, and 78.1 ± 5.9 degrees, respectively, before operation to 89.2 ± 2.1 degrees, 0.4 ± 0.5 degrees, and 88.7 ± 2.3 degrees, respectively, after operation. HA, HR, and HD also changed from -9.2 ± 4.6 degrees, 0.66 ± 0.18, and -11.2 ± 6.9 mm to -3.7 ± 4.1 degrees, 0.48 ± 0.14, and -5.0 ± 5.3 mm. All the changes were statistically significant (P < .001, respectively). The regression slope of correlation was 0.390 (R2 = 0.654) between TTS and HA; 0.017 (R2 = 0.617) between TTS and HR; and 0.560 (R2 = 0.703) between TTS and HD. CONCLUSION: In patients with end-stage varus ankle OA, changes of hindfoot alignment could be predicted based on degree of ankle deformity corrected with TAA. LEVEL OF EVIDENCE: Level IV, case series.