[Ankle cartilage repair : Therapeutic options, results and technical aspects]

Electromagnetic navigation reduces radiation exposure for retrograde drilling in osteochondrosis dissecans of the talus

Background

Retrograde drilling in osteochondrosis dissecans (OCD) is a widely used surgical intervention. A radiation-free electromagnetic navigation system (ENS)-based method was compared with the standard freehand fluoroscopic (SFF) method regarding clinical applicability.

Methods

We performed a clinical cohort study at a department of Orthopaedics in a Level 1 children’s hospital with 40 patients (20 SFF and 20 ENS). Retrograde drilling of the talar dome was used in patients with unstable medial OCD (MRI stage 2 according to Hepple’s revised classification; stage 2 according to the International Cartilage Repair Society). The outcome measurements were: (a) Intraoperative fluoroscopy exposure and length of surgery and (b) Postoperative serial follow-up MRIs every 6 months.

Results

22 female and 18 male patients aged 13.8 ± 1.6 years (range: 11–17 years) were included. Using the ENS technique, length of surgery was significantly reduced to 20.2 ± 6.4 min compared to 36.1 ± 11.8 min (p < 0.01) for the SFF technique. The average x-ray radiation time for the SFF technique was 23.5 ± 13.5 sec and 1.9 ± 1.7 sec for the ENS technique (p < 0.01). Radiation exposure was significantly reduced from 44.6 ± 19.7 mSv (SFF technique) to 5.6 ± 2.8 mSv (ENS technique) (p < 0.01). Intraoperative perforation of cartilage occurred once in the SFF group. Correct placement of the drilling channel was verified in all patients on follow-up MRI after six months and a timely healing was seen after two years.

Conclusions

The ENS method provides for a significant reduction in length of surgery and radiation exposure. ENS was without intraoperative cartilage perforation. The clinical and radiological follow-up parameters are comparable for SFF- and ENS-guided retrograde drilling.

Trial registration

WF – 085/20, 05/2020 “retrospectively registered” https://www.aerztekammer-hamburg.org/ethik_kommission.html.

[Refixation of osteochondral fragments with resorbable polylactid implants : Long-term clincal and MRI results]

BACKGROUND

Refixation with resorbable implants is a common surgical treatment in patients who suffer an injury with shearing of an osteochondral flake due to trauma of the knee or the upper ankle joint. To date there are no studies which outline long-term outcomes for this procedure. The aim of this study was to evaluate long-term clinical and magnetic resonance imaging (MRI) results after refixation with resorbable polylactide (PLLA) implants.

MATERIAL AND METHODS

In this retrospective study 12 patients with 13 injuries were examined 13.9 years (±1.2 years) after refixation of an osteochondral fragment of the knee (10 patients) and the upper ankle joint (2 patients) with a mean size of 3.33 cm² (±2.33) by resorbable polylactide (PLLA) implants (nails, pins, screws, Bionx, Tampere, Finland). To objectify the clinical results eight established clinical scores (VASS, Tegner, Lysholm, McDermott, KSS, WOMAC, AOFAS, FADI+Sports) were used. Furthermore, the morphological integration of bone and cartilage was assessed by MRI (3 T) using proton-weighted and cartilage-sensitive 3D double-echo steady-state (DESS) sequences. The morphological results were objectified with a modified MRI score according to Henderson et al.

RESULTS

After 13.9 years (±1.2) the patients with an injury of the knee as well as of the upper ankle joint showed good to excellent results (knee: VASS 1.2 (±1.7), Tegner 4.4 (±1.3), Lysholm 85.7 (±12.2), McDermott 90.7 (±8.6), KSS 189 (±14.2), WOMAC (6.16% (±8.45)) (upper ankle joint: VASS 2.5 (±2.5), Tegner 5.5 (±1.5), Lysholm 87 (±13), McDermott 88 (±12); WOMAC (8.54% (±8.54), AOFAS 75.5 (±24.5), FADI+Sports 118 (±18)). In all cases there was evidence of good integration of the osteochondral fragment in MRI. In five patients there was moderate subchondral cyst formation (∅ ≤1 mm); however, mild changes of the cartilage contour were found in all patients. The mean modified Henderson score achieved was 14.4 (±2.0, best 8, worst 32), which corresponds to a good morphological result.

CONCLUSION

Because of good clinical and morphological results shown by MRI, refixation through resorbable implants (PLLA) can be recommended for treatment of traumatic osteochondral flakes.

[Operative treatment of cartilage lesions]

Cartilage damage is often associated with pain, reduced quality of life and decreased physical performance. In addition, even small cartilage lesions can lead to osteoarthritis. Since young active people are particularly affected, the correct treatment of cartilage damage plays an important role. Operative treatment includes bone marrow-stimulating procedures with or without a matrix, cell-based procedures and osteochondral graft transplantation. The choice of the best procedure depends on the localization, the size and the extent of the cartilage damage. In addition, especially in the treatment of cartilage damage to the lower limbs, the leg axis and loading relationships should be taken into account and possibly treated as well as additional joint instabilities. The following article gives an overview of the available surgical treatment possibilities as well as the correct indications and implementation. It also gives a brief projection of possible further treatment options associated with stem cells.