Osteochondral Defects of the Talus: How to Treat Without an Osteotomy

Partial talar replacement with a novel 3D printed prosthesis

BACKGROUND

The treatment of talus avascular necrosis (AVN) is challenging owing to its unique anatomical features. Despite decades of studies, till date, there is no appropriate treatment for talus AVN. Therefore, surgeons need to develop newer surgical methods. In the present study we introduce a new surgical method, 3D printed partial talus replacement (PTR), to treat partial talus necrosis and collapse (TNC).

METHODS

A male patient with talus AVN underwent PTR in our hospital. The morphology of the talus was quantified using 3D computed tomography (CT) imaging. A novel 3D printed titanium prothesis was designed and manufactured according to the findings of the CT imaging. The prosthesis was applied during talus replantation surgery to reconstruct the anatomical structure of the ankle. The follow-up period for this patient was 24 months. The visual analog scale (VAS) scores before and after surgery, American Orthopedic Foot and Ankle Score (AOFAS), ankle range of motion, and postoperative complications were recorded to evaluate the prognosis.

RESULTS

The anatomical structure of the talus was reconstructed. The patient was satisfied with the effects of treatment, recovery, and function. The VAS score decreased from 5 to 1. The AOFAS improved from 70 to 93. The range of motion remained the same as that during the pre-operation. The patient returned to a normal life.

CONCLUSION

3D printed PTR is a new surgical method for talus AVN that can provide satisfactory outcomes. In future, PTR might be an effective and preferential treatment for the treatment of partial talus AVN and collapse.

Retrograde Drilling and Bone Graft for Hepple Stage V Subchondral Bone Lesion of Talus Using 3D Image-Based Navigation-Assisted Endoscopic Technique

BACKGROUND

Retrograde drilling remains technically challenging, because of the difficulty of identifying the accurate location of cysts during surgery. This study's aim was to evaluate the 3-dimensional (3D) image-based surgical navigation-assisted endoscopic retrograde drilling technique for subchondral bone lesions of the talus.

METHODS

From March 2017 to June 2020, a total of 21 cases with Hepple stage V subchondral bone lesions of the talus were treated with 3D image-based surgical navigation-assisted endoscopic retrograde drilling and bone graft technique. Arthroscopic views were categorized per Pritsch classifications. The correlation between the drilled tunnel with preoperative cystic lesions were assessed under postoperative computer tomographic (CT) scans. The American Orthopaedic Foot & Ankle Society (AOFAS) scores, visual analog scale (VAS) scores, and Foot and Ankle Ability Measure (FAAM) sports scales were evaluated at the preoperative and final consultation. All complications were recorded.

RESULTS

On postoperative CT scans, in 20 cases (95.2%), the drilled tunnel was judged to have been in the center of previous cysts. Only 9 cases (42.9%) showed intact normal cartilage (grade 0, group A); 12 cases (57.1%) had intact, but soft, cartilage (grade I, group B). The median follow-up time was 24 (24, 30) months, and at final follow-up, there were no significant differences between the mean AOFAS and VAS scores in both groups (89.0 ± 6.4 vs 88.3 ± 7.0 and 1 vs 0.5) or postoperative FAAM sports scales (28.2 ± 2.2 vs 26.6 ± 4.9, P = .363). Two patients had revision surgery in group B.

CONCLUSION

The 3D image-based surgical navigation-assisted endoscopic retrograde drilling and bone graft technique for the subchondral bone lesions of the talus in this small case series showed encouraging results.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

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.

Self-assembled insulin-like growth factor 1 peptides induce adipose stem cell differentiation to repair cartilage injury

BACKGROUND

Tissue engineering using adipose-derived mesenchymal stem cells (ADSCs) promotes the regeneration of articular cartilage. However, insulin-like growth factor 1 (IGF-1), which is used to induce the differentiation of ADSCs into chondrocytes during treatment, is prone to instability and short tissue retention.

METHODS

Nap-FFG-GYGSSSRRAPQT was used as an IGF-1 mimicking molecule. MTT and CCK-8 assays were performed to evaluate the proliferation ability of ADSCs. QRT-PCR and Western blot assays were used to assess the expression of cartilage-related genes. International Cartilage Regeneration and Joint Preservation Society (ICRS) scoring was used for the evaluation of cartilage repair. Repaired tissues were analyzed by hematoxylin-eosin, Safranin-O and immunohistochemical staining.

RESULTS

Nap-FFG-GYGSSRRAPQT stimulated the proliferation and migration of ADSCs through the activation of IGF-1 receptor. Gel Nap-FFG-GYGSSRRAPQT treatment upregulated the expression of cartilage-related genes in ADSCs. ADSCs/Gel Nap-FFG-GYGSSRRAPQT treatment significantly promoted the regeneration of cartilages.

CONCLUSION

Self-assembled IGF-1 peptide, Nap-FFG-GYGSSRRAPQT, can induce ADSC differentiation and proliferation to repair cartilage injury.

Limited medial osteochondral lesions of the talus associated with chronic ankle instability do not impact the results of endoscopic modified Broström ligament repair

Background

The arthroscopic modified Broström procedure, with repair of the anterior talofibular ligament and extensor retinaculum, produces good functional outcomes in patients with chronic lateral ankle instability (CLAI). CLAI can be associated with osteochondral lesions of the talus (OLTs). It remains unclear whether associated limited OLTs affect clinical outcomes in such patients.

Methods

This retrospective cohort study included 92 CLAI patients with and without OLTs undergoing an all-inside arthroscopic modified Broström procedure from June 2016 to May 2019. The patients were divided into non-lesion group (n = 32) and lesion group (n = 60) according to whether CLAI was associated or not with OLTs. All the osteochondral lesions less than 15 mm in diameter were managed with bone marrow stimulation techniques (arthroscopic microfracture) at the time of the arthroscopic modified Broström procedure. The Visual Analogue Scale (VAS) scores, American Orthopedic Foot and Ankle Society (AOFAS) scores, Karlsson Ankle Function Score (KAFS), Anterior Talar Translation (ATT), Active Joint Position Sense (AJPS), and the rate of return to sports were compared in both groups.

Results

Increase in all the functional scores (VAS, AOFAS, KAFS, ATT, and AJPS) in both groups was, respectively, recorded 1 year and 2 years after surgery. At the 1-year and 2-year follow-up, there was no significant difference in the VAS, AOFAS, KAFS, ATT, and AJPS scores between the non-lesion and lesion groups.

Conclusion

In patients with CLAI who underwent an arthroscopic modified Broström procedure, the presence of limited OLTs (less than 15 mm in diameter), which required arthroscopic microfracture, did not exert any influence on outcome.

Level of Evidence

Level III, a retrospective comparative study.