Both Magnetic Resonance Imaging and Computed Tomography Are Reliable and Valid in Evaluating Cystic Osteochondral Lesions of the Talus

Osteochondral Lesion of the Talus: Quality of Life, Lesion Site, and Lesion Size

Osteochondral lesions of the talus (OLTs) are the lesions that affect the articular cartilage and the subchondral bone of the talus. Symptoms develop between 6 and 12 months after the index trauma and are associated with degradation of quality of life. Two-thirds of the lesions (73%) are located on the medial part of the talus, 28% of the lesions are posteromedial, and 31% of the lesions are centromedial. Currently, OLT of up to 100 mm2 can behave in a more indolent condition, and above that area, the defect tends to transmit more shearing forces to adjacent cartilage and is more symptomatic.

Preoperative and Postoperative Imaging and Outcome Scores for Osteochondral Lesion Repair of the Ankle

Cartilage lesions to the ankle joint are common and can result in pain and functional limitations. Surgical treatment aims to restore the damaged cartilage's integrity and quality. However, the current evidence for establishing best practices in ankle cartilage repair is characterized by limited quality and a low level of evidence. One of the contributing factors is the lack of standardized preoperative and postoperative assessment methods to evaluate treatment effectiveness and visualize repaired cartilage. This review article seeks to examine the importance of preoperative imaging, classification systems, patient-reported outcome measures, and radiological evaluation techniques for cartilage repair surgeries.

Medial cystic osteochondral lesions of the talus exhibited lower sports levels, higher cyst-presence rate, and inferior radiological outcomes compared with lateral lesions following arthroscopic bone marrow stimulation

PURPOSE

To compare the patient-reported outcomes and radiological outcomes of the patients with medial- and lateral-cystic osteochondral lesions of the talus (OLTs) following bone marrow stimulation (BMS).

METHODS

Patients with cystic OLTs who underwent BMS between January 2016 and February 2021 were retrospectively analyzed, and the minimum follow-up time was more than 24 months. Patients were paired in a 1:1 ratio (medial-: lateral-cystic OLT; MC-OLT: LC-OLT) based on the OLT area within 30mm2, follow-up within 1 year, age within 5 years, and ligament surgery (Yes/No). The Visual analog scale, Foot and Ankle Ability Measure (FAAM)-Activities of Daily Life and Sports scores were assessed preoperatively and postoperatively. The magnetic resonance observation of cartilage repair tissue (MOCART) scores, and presence of cysts after BMS were also evaluated. Additionally, the receiver operating characteristic curve was performed.

RESULTS

The matched patients were divided into the MC-OLT(n=31, 43.35±12.32 months) and LC-OLT groups (n=31, 43.32±14.88 months, P=.986). Thirty patients of each group achieved a power of 80% and an α = 0.05 in this study. The MC-OLT group showed significantly less improvement in FAAM-ADL and sports scores (P = .034, P <0.001, respectively), lower MOCART scores (80.80±11.91 vs. 86.00±8.50, P = .010), and higher presence-rate of cyst after BMS (45.16% vs. 16.12%, P = .013). Regarding FAAM sports scores, the LC-OLT group had significantly more patients exceeding the MCID (80.64% vs. 51.61%, P = .031). Furthermore, an OLT depth of 7.23mm (sensitivity: 78.6%; specificity: 70.6%) might serve as a cut-off value for predicting the presence of cysts in medial-cystic OLTs following BMS.

CONCLUSION

Medial cystic OLTs exhibited markedly lower sports levels, higher cyst-presence rate, and inferior radiological outcomes following BMS than lateral counterparts. Additionally, an OLT depth of 7.23mm could be the cut-off value for predicting the presence of cysts regarding medial-cystic OLTs after BMS.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Reporting of Morphology, Location, and Size in the Treatment of Osteochondral Lesions of the Talus in 11,785 Patients: A Systematic Review and Meta-Analysis

OBJECTIVE

Uniformity of reporting is a requisite to be able to compare results of clinical studies on the treatment of osteochondral lesions of the talus (OLT). The primary aim of this study was to evaluate the frequency and quality of reporting of size, morphology, and location of OLTs.

DESIGN

A literature search was performed from 1996 to 2023 to identify clinical studies on surgical treatment of OLTs. Screening was performed by 2 reviewers, who subsequently graded the quality using the methodological index for non-randomized studies (MINORS). The primary outcome was the frequency and qualitative assessment of reporting of size, morphology, and location.

RESULTS

Of 3,074 articles, 262 articles were included. This comprised a total of 11,785 patients. Size was reported in 248 (95%) of the articles and was described with a measure for surface area in 83%, however, in 56%, definition of measurement is unknown. Intraclass coefficient (ICC) value for the reliability of size measurement was 0.94 for computed tomography (CT) scan and 0.87 for MRI scan. Morphology was reported in 172 (66%) of the articles and using a classification system in 23% of the studies. Location was reported in 220 (84%) of the studies.

CONCLUSION

No consensus was found on the reporting of morphology, with non-validated classification systems and different terminologies used. For location, reporting in 9 zones is underreported. Size was well reported and measurements are more reliable for CT compared with MRI. As these prognostic factors guide clinical decision-making, we advocate the development of a standardized and validated OLT classification to reach uniform reporting in literature.

LEVEL OF EVIDENCE

Level III, systematic review.

Concomitant Subchondral Bone Cysts Negatively Affect Clinical Outcomes Following Arthroscopic Bone Marrow Stimulation for Osteochondral Lesions of the Talus

PURPOSE

To study the effects of concomitant subchondral bone cysts (SBCs) on prognosis after arthroscopic bone marrow stimulation (BMS) for osteochondral lesions of the talus (OLTs) less than 100 mm2 and to further assess the correlation between cystic OLT area, depth, or volume and postoperative outcomes.

METHODS

We retrospectively analyzed consecutive patients with OLTs (<100 mm2) who received BMS between April 2017 and May 2020 with a minimum follow-up of 24 months. Lesion area, depth, and volume were collected on preoperative magnetic resonance imaging. Visual analog scale (VAS), American Orthopedic Foot and Ankle Society, Karlsson-Peterson, Tegner, Foot and Ankle Ability Measure (FAAM)-Activities of Daily Life and Sports scores were assessed before surgery and at the latest follow-up. Additionally, a general linear model (GLM) and a Pearson correlation analysis (PCA) were performed to investigate the effects of concomitant cysts on postoperative results.

RESULTS

Eighty-two patients with a mean follow-up of 39.22 ± 12.53 months were divided into non-cyst (n = 45; 39.91 ± 13.03 months) and cyst (n = 37; 38.37 ± 12.02 months) groups. There was no significant difference in the OLT area between the non-cyst and cyst groups (46.98 ± 19.95 mm2 vs 56.08 ± 22.92 mm2; P = .093), but the cyst group showed significantly greater depth (6.06 ± 1.99 mm vs 3.96 ± 1.44 mm; P = .000) and volume (248.26 ± 156.81 mm3 vs 134.58 ± 89.68 mm3; P = .002). The non-cyst group showed significantly more improvement in VAS pain, Karlsson-Peterson, Tegner, and FAAM scores than the cyst group (P < .05). The GLM indicated that SBCs negatively affected VAS pain and Tegner scores (P < .05). For OLTs with cysts, the PCA showed that an area of 90.91 mm2, depth of 7.56 mm, and volume of 428.13 mm3 were potential cutoff values associated with poor outcomes.

CONCLUSIONS

The concomitant SBCs negatively affected the prognosis of OLTs after BMS. For OLTs with cysts, an area of 90.91 mm2, depth of 7.56 mm, and volume of 428.13 mm3 were the potential cutoff values associated with poor outcomes after BMS.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Comparison of surface microscopy coil and ankle joint special phased array coil magnetic resonance imaging in assessing preoperative osteochondral lesions of the talus

Background

Lesion size is a major determinant of treatment strategies and predictor of clinical outcomes for osteochondral lesions of the talus (OLTs). Although magnetic resonance imaging (MRI) has been commonly used in the preoperative evaluation of OLTs, MRI has low reliability and usually overestimates or underestimates lesion size compared with intraoperative assessment. This study aims to determine whether the surface microscopy coil (SMC) can improve the accuracy of assessment of preoperative OLTs compared with conventional coil MRI, ankle joint special phased array coil (ASC).

Methods

A total of 43 patients diagnosed with OLTs undertook preoperative MRI examination with both SMC and ASC were included in this prospective study from 2019 to 2022. The diameter of the lesion was measured in sagittal plane and coronal plane at its widest point and then the lesion area was calculated. Then MRI measurements were compared with arthroscopy or open-surgery measurements.

Results

The mean lesion area measured with ASC was significantly greater than that measured intraoperatively (95.07±44.60 vs. 52.74±29.86 mm2, P<0.001), while there was no significant difference between lesion area measured in SMC and intraoperatively (55.28±36.06 vs. 52.74±29.86 mm2, P=0.576). Diameter measured in ASC was significantly greater than that measured intraoperatively in both coronal plane (8.95±2.48 vs. 6.67±1.81, P<0.001) and sagittal plane (13.12±3.76 vs. 9.58±3.98, P<0.001). No significant difference between lesion diameter measured in SMC and intraoperatively in both coronal plane (6.44±2.59 vs. 6.67±1.81, P=0.608) or sagittal plane (10.23±3.69 vs. 9.58±3.98, P=0.194). Compared with surgical assessment, 39 of 43 cases were consistent with SMC assessment while only 26 of 43 cases were consistent with ASC assessment (39/43 vs. 26/43, P=0.002).

Conclusions

Diameter measured with SMC was much more accurate than ASC MRI. Compared with ASC MRI, the SMC had a much higher concordance rate between preoperative assessment and surgical assessment.

Clinical Outcomes After Arthroscopic Microfracture Treatment of Coexisting Talar and Tibial Osteochondral Lesions

Background

Despite increased recognition of coexisting tibial and talar osteochondral lesions (OCLs), the risk factors influencing clinical outcomes remain unclear.

Purpose

To report clinical follow-up results after arthroscopic microfracture surgery in patients with OCLs of the distal tibial plafond and talus and assess possible factors affecting these clinical outcomes.

Study Design

Case series; Level of evidence, 4.

Methods

A total of 40 patients with coexisting talar and tibial OCLs who underwent arthroscopic microfracture surgery were included. For analysis, the study used the American Orthopaedic Foot & Ankle Society (AOFAS) scale, Karlsson-Peterson scale, and visual analog scale (VAS) for pain for clinical evaluations on the day before surgery, 12 months after surgery, and at the last follow-up. A stepwise regression model and Spearman rank correlation were used to assess possible factors affecting these clinical outcomes.

Results

The median follow-up time was 34.5 months (interquartile range [IQR], 26.5-54 months). At the final follow-up, the cohort included 40 patients (26 men and 14 women) with a mean age of 38.8 years (range, 19-60 years). The median AOFAS score increased from 57.5 (IQR, 47-65) before surgery to 88 (IQR, 83-92.5) at the final follow-up, the median Karlsson-Peterson score increased from 48 (IQR, 38.5-67) to 82 (IQR, 76-92), and the median VAS score improved from 5 (IQR, 4-6) to 1 (IQR, 0-2). All scale scores showed significant differences between the preoperative and final follow-up evaluations (P < .001). In the stepwise regression model and Spearman rank correlation analysis, the grade of tibial OCL had a significant independent effect on the final postoperative AOFAS scores of the patients (β = -0.502, P = .001; r = -0.456, P = .003). The size of the tibial lesion also had a significant independent effect on the final postoperative Karlsson-Peterson scores of the patients (β = -0.444, P = .004; r = -0.357, P = .024).

Conclusion

Arthroscopic microfracture treatment for coexisting talar and tibial OCLs can achieve good short- to midterm clinical outcomes. The grade and size of tibial OCLs are the main risk factors affecting the prognostic functional scores of such patients.

Favourable clinical, arthroscopic and radiographic outcomes after autologous osteoperiosteal transplantation for massive medial cystic osteochondral defects of the talus

PURPOSE

The purpose of this study was to retrospectively evaluate the clinical, arthroscopic and radiological outcomes of autologous osteoperiosteal transplantation for massive cystic osteochondral defects of the talus.

METHODS

Cases of autologous osteoperiosteal transplantation for medial massive cystic defects of the talus between 2014 and 2018 were reviewed. The visual analogue scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS) score, Foot and Ankle Outcome Score (FAOS), and Ankle Activity Scale (AAS) were assessed preoperatively and postoperatively. The Magnetic Resonance Observation of Cartilage Tissue (MOCART) system and the International Cartilage Repair Society (ICRS) score were evaluated after surgery. The ability to return to daily activity and sport, as well as complications, were recorded.

RESULTS

Twenty-one patients were available for follow-up, with a mean follow-up of 60.1 ± 11.7 months. All subscales of preoperative FAOS had significant (P < 0.001) improvement at the final follow-up. The mean AOFAS and VAS scores significantly (P < 0.001) improved from 52.4 ± 12.4 preoperatively to 90.9 ± 5.2 at the last follow-up and from 7.9 ± 0.8 to 1.5 ± 0.9, respectively. The mean AAS decreased from 6.0 ± 1.4 preinjury to 1.4 ± 0.9 postinjury and then increased to 4.6 ± 1.4 at the final follow-up (P < 0.001). All 21 patients resumed daily activities after a mean of 3.1 ± 1.0 months. Fifteen patients (71.4%) returned to sports after a mean of 12.9 ± 4.1 months. All patients underwent follow-up MRI with a mean MOCART score of 68.6 ± 5.9. Eleven patients underwent second-look arthroscopy, and the average ICRS was 9.4 ± 0.8. No donor site morbidity was found in any patient during the follow-up.

CONCLUSION

Autologous osteoperiosteal transplantation provided favourable clinical, arthroscopic and radiographic outcomes in patients with massive cystic osteochondral defects of the talus during a minimum 3-year follow-up.

LEVEL OF EVIDENCE

IV.

Arthroscopic defect size measurement in osteochondral lesions of the talus underestimates the exact defect size and size measurement with arthro-MRI (MR-A) and high-resolution flat-panel CT-arthro imaging (FPCT-A)

PURPOSE

The size of osteochondral lesions of the talus (OLTs) is highly relevant for their treatment. In addition to intraoperative measurement of defect size, preoperative planning by means of magnetic resonance imaging (MRI) or computed tomography (CT) is crucial.

METHODS

Four defects of different sizes and depths were created on the talar joint surface in 14 cadaver feet. All defects were evaluated, both arthroscopically and via arthrotomy with a probe. Arthro-MRI (MR-A) and high-resolution flat-panel CT arthro scans (FPCT-A) were acquired. Length, width, and depth were measured for every defect and the defect volume was calculated. To determine the exact defect size, each talar defect was filled with plastic pellets to form a cast and the casts were scanned using FPCT to create a 3D multiplanar reconstruction data set. Finally, the surgically measured values were compared with the radiological values and the exact defect size.

RESULTS

Overall, the surgically measured values (both arthroscopic and open) underestimated the exact defect size (p < 0.05). Arthroscopically determined defect length and width showed the largest deviation (p < 0.05) and underestimated the size in comparison with MR-A and FPCT-A. The FPCT-A measurements demonstrated higher correlation with both the arthroscopic and open surgical measurements than did the MR-A measurements (p < 0.05).

CONCLUSION

The exact defect size is underestimated on intraoperative measurement, in both arthroscopic and open approaches. Arthroscopic defect size measurement underestimates defect size in comparison with MR-A and FPCT-A. FPCT-A was shown to be a reliable imaging technique that allows free image reconstruction in every plane and could be considered as the new reference standard for preoperative evaluation of defect size in OLT.

SPECT/CT imaging features of cystic degeneration of the talus and their relation to pathological findings

Background

Osteochondral lesions of the talus (OLTs) are a common orthopedic condition. The image presentation is very similar to that of ischemic necrosis of the talus complicated by a talar neck fracture, but the two are very different lesions. When abnormalities in bone density (or signal) of the talar body (apex of the fornix) with concomitant bone defects and cystic changes are found on X-ray, computed tomography (CT), or magnetic resonance imaging, it is important to accurately determine the nature of the lesion and make a correct diagnosis for the treatment and prognosis of the patient. The purpose of this study was to explore the imaging features of three-phase single-photon emission computed tomography (SPECT)/CT images of cystic lesions of the talus.

Methods

A total of 189 patients with chronic pain in the ankle joint suspected to be caused by cystic degeneration of the talus were enrolled. All patients underwent 99mTc-methyl diphosphonate (99mTc-MDP) three-phase SPECT/CT bone imaging and delayed scans in our hospital. The location, range of involvement, classification, CT value, and radioactivity uptake of the sclerotic areas of cystic lesions on the talus, and the continuity of the articular surface, were recorded. All recorded parameters were analyzed in comparison with pathological results.

Results

Eighty-three percent (157/189) of the talar cysts were located on the medial fornix, largely involving the anterior middle part (43.27%), with larger cysts involving the posterior part (9.6%). Sixty-three percent (119/189) of the patients had type I lesions and 37% (70/189) had type II lesions. The articular surface of the medial dome of the talus was intact in all patients, but the subchondral bony articular surface was rough in 88% (166/189) of patients. The coincidence rate for the location, type, and range of involvement of cystic lesions with the pathological results was 87.83% (166/189). The mean CT value of the cystic lesions was 45 ± 15 HU (30–60 HU). The percentages of pathological chondrogenesis in high CT value ≥ 50 HU (19/70) and low CT value < 50 HU (51/70) groups were 89.47% (17/19) and 29.14% (15/51) (χ² = 20.12, p < 0.001), respectively. The target/background ratio (T/B ratio) of the radioactivity-uptake area of the talus vault was 2.0 ± 0.5 (1.5–2.5). The percentages of pathological new trabecular bone in those with a T/B ratio ≥ 2.0 (157/189) and T/B ratio < 2.0 (32/189) were 82.80% (130/157) and 25.00% (8/32; χ² = 45.08, p < 0.001), respectively.

Conclusions

Three-phase bone imaging could identify damage of the talus caused by cystic degeneration, while delayed SPECT/CT images showed advantages for displaying bone microstructure, blood supplement, and bone metabolism when examining the location, range of involvement, classification, and repair of cystic lesions of the talus.

Autologous matrix induced chondrogenesis (AMIC) as revision procedure for failed AMIC in recurrent symptomatic osteochondral defects of the talus

Autologous matrix induced chondrogenesis (AMIC) is a bone marrow stimulating technique used for the surgical management of chondral defects of the talus. The present study evaluated the clinical outcomes and imaging of AMIC as revision procedure for failed AMIC surgery for osteochondral defects of the talus. Forty-eight patients with symptomatic osteochondral defects who received a revision AMIC were evaluated after a minimum of two years follow-up. Patients with previous procedures rather than AMIC, those who required additional surgical procedures (e.g. ligament repair or deformity correction), or those who had evidence of kissing, bilateral, or multiple lesions were excluded. Outcome parameters included the Visual Analogic Scale (VAS), Tegner Activity Scale, the American Orthopedic Foot and Ankle Score (AOFAS), and the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score. All patients were followed by an assessor who was not involved in the clinical management. 27 patients were enrolled in the present study. The mean age of the patient was 34.9 ± 3.1 years, and the mean BMI 27.2 ± 5.1 kg/m². The mean defect surface area was 2.8 ± 1.9 cm². The mean follow-up was 44.3 ± 21.4 months. The mean hospital length of stay was 4.4 ± 1.4 days. At final follow-up, the mean VAS score was 4.1 ± 3.1, the mean Tegner 3.5 ± 1.6, the mean AOFAS 58.8 ± 20.6. The preoperative MOCART score was 22.1 ± 13.7 points, the postoperative MOCART score was 42.3 ± 27.9 points (+ 20.2%; P = 0.04), respectively. 30% (8 of 27 patients) experienced persistent pain and underwent a further chondral procedure. Concluding, AMIC could be a viable option as revision procedure for failed AMIC in recurrent symptomatic osteochondral defects of the talus. The PROMs indicated that patients were moderately satisfied with the procedure, and the MOCART score demonstrated a significant improvement from baseline to the last follow-up. A deeper understanding in prognostic factors and patient selection is critical to prevent failures.

Outcomes of Single-Stage Versus Staged Treatment of Osteochondral Lesions in Patients With Chronic Lateral Ankle Instability: A Prospective Randomized Study

Background:

There is controversy about whether treatment of chronic lateral ankle instability (CLAI) with osteochondral lesions of the talus (OLT) can be performed concurrently.

Purpose:

To investigate the midterm results of arthroscopic treatment of CLAI combined with OLT in different surgical settings. It was hypothesized that the outcomes of treating both injuries at the same time would not be inferior to those of staged surgery.

Study Design:

Randomized controlled trial; Level of evidence, 1.

Methods:

Included were 103 patients with both CLAI and OLT who underwent arthroscopic microfracture surgery and an open, modified Broström-Gould procedure for ligament repair from January 2015 to December 2016. The patients were assigned randomly to a staged group (51 patients) and a single-stage group (52 patients). The staged group underwent arthroscopic debridement of the OLT and microfracture, then rehabilitation for 4 to 6 months before undergoing modified Broström-Gould ligament repair. The single-stage group underwent both procedures simultaneously. Clinical evaluations were performed on the day before surgery and at 12-month, 24-month, and final follow-up periods using the Karlsson-Peterson score, American Orthopaedic Foot & Ankle Society (AOFAS) score, and pain visual analog scale. The Karlsson-Peterson score at 24 months postoperatively was considered the primary outcome. The predefined noninferiority margin for the primary outcome was −5 points.

Results:

At the final follow-up, 50 patients in the single-stage group and 48 patients in the staged group completed the study. The median lesion size was 0.72 cm² (interquartile range [IQR], 0.5-1.12 cm²) in the single-stage group and 0.84 cm² (IQR, 0.7-1.05 cm²) in the staged group. At 12-month follow-up, the single-stage group had a significantly higher median Karlsson-Peterson score (79 [IQR, 70-85] vs 75 [IQR 65-80] for staged; P = .024) and median AOFAS score (85 [IQR, 76-89] vs 79.5 [IQR, 70-87] for staged; P = .045). At 24-month follow-up, the median difference in the Karlsson-Peterson score for single-stage versus staged surgery was 2 points (95% CI, −2 to 5 points), and the confidence interval was greater than the predefined value.

Conclusion:

At midterm follow-up, there was no clinical difference between single-stage versus staged surgery to treat CLAI with OLT. Single-stage surgery achieved better clinical outcomes than staged surgery at short-term follow-up.

High resolution flat-panel CT arthrography vs. MR arthrography of artificially created osteochondral defects in ex vivo upper ankle joints

PURPOSE

High resolution flat-panel computed tomography arthrography (FPCT-A) and magnetic resonance arthrography (MR-A) are well suited to evaluate osteochondral lesions. The current study compares the performance of FPCT-A versus MR-A in an experimental setting.

METHODS

Fourteen cadaveric ankles were prepared with artificial osteochondral defects of various sizes in four separate talar locations. After intra-articular contrast injection, FPCT-A and 3-T MR-A were acquired. Each defect was then filled with synthetic pallets. The resulting cast was used as reference. Two independent radiologists measured the dimensions of all defects with FPCT-A and MR-A. Intra-class correlation coefficients (ICC) were calculated. Data were compared using t-tests and Bland-Altman plots.

RESULTS

The correlation for FPCT-A and cast was higher compared to MR-A and cast (ICC 0.876 vs. 0.799 for surface [length x width]; ICC 0.887 vs. 0.866 for depth, p<0.001). Mean differences between FPCT-A and cast measurements were -1.1 mm for length (p<0.001), -0.7 mm for width (p<0.001) and -0.4 mm for depth (p = 0.023). By MR-A, there were no significant differences for length and width compared to cast (p>0.05). Depth measurements were significantly smaller by MR-A (mean difference -1.1 mm, p<0.001). There was no bias between the different modalities.

CONCLUSIONS

Ex vivo FPCT-A and MR-A both deliver high diagnostic accuracy for the evaluation of osteochondral defects. FPCT-A was slightly more accurate than MR-A, which was most significant when measuring lesion depth.