[Retropatellar autologous cartilage-bone transplantation. A treatment option in severe cartilage damage]

Patellar chondral defects: a review of a challenging entity

PURPOSE

The aim of this study was to perform a review of the management of patellar cartilage defects, identify prognostic factors for better clinical outcomes, and propose a treatment algorithm of this challenging entity.

METHODS

We conducted a review of multiple databases, evaluating the clinical outcomes after patellar cartilage lesion treatment. Because of the heterogeneity of data, a meta-analysis could not be performed.

RESULTS

Twelve studies were identified for inclusion. Based on the clinical outcomes of these studies, a treatment algorithm was proposed. The clinical outcomes after patellar cartilage defects repair depend on the location and size of the articular defect, the age of the patient, the successful reconstruction of the patellar ridge, the repair of extensor mechanism malalignment, and the coexistence of chondromalacia.

CONCLUSION

The optimal treatment for cartilaginous defects of the patella is still elusive. More prospective studies are needed, in order to identify which techniques are cost-effective especially on a long-term basis.

[Autologous osteochondral transplants]

Osteochondral transplantation is a treatment option for restoring lesions of the cartilage surface and the underlying subchondral bone. For this technique, osteochondral cylinders are taken from less loaded regions of the knee joint and brought into the defect. It is based on press-fit implantation of osteochondral cylinders that are harvested from the mediocranial or laterocranial aspect of the patellofemoral joint with subsequent stable bony integration of the transplant. Indications for osteochondral transplantation must consider clinical, radiological, and magnetic resonance aspects, and concomitant pathologies of the joint should be eliminated. Isolated grade III and IV cartilage lesions in the load-bearing area of the medial or lateral femoral condyle are considered to be ideal indications for osteochondral transplantations. Further indications are retropatellar defects and lesions of the medial aspect of the talus. The technique is established for defects from 1 cm2 to 3 cm2. At this time, osteochondral transplantation is the only surgical method to achieve long-term coverage of the defect with hyaline cartilage. Donor site morbidity at the patellofemoral joint needs to be discussed because, particularly after the harvest of several cylinders, pain syndromes can develop. Therefore, the technique should be limited to two cylinders with a maximum diameter of 12 mm and one further cylinder with a smaller diameter.

Operative treatment of deep chondral defects of the patella: results after abrasive arthroplasty and periosteal arthroplasty

This prospective, non-randomized study was aimed to evaluate the effects of abrasive arthroplasty and periosteal arthroplasty in the treatment of deep chondral defects of the patella. A total of 30 patients in group A (13 male, 17 female, age: 28.7+/-6.9 years) underwent arthroscopic abrasive arthroplasty. The other patients in group B (n=17, 11 male, 8 female, age 26.8+/-7.0 years) underwent periosteal arthroplasty by an autologous periosteal flap. The maximal diameter of the defects was 31.1+/-6.7 (range 20-45 mm). The Lysholm score and the intensity of pain were evaluated preoperatively and at the time of follow-up (3.1+/-1.1, range 2-5 years). The Tegner activity score was evaluated before onset of the symptoms and at the time of follow-up. The Lysholm score increased significantly in both groups (in group a from 36.1+/-7.1 to 42.5+/-6.6 points and in group B from 42.7+/-2.4 to 67.6+/-7.8 points). The result in group B was significantly better than in group A. In group A the intensity of pain was unchanged, whereas patients from group B reported a significant reduction of pain. The level of physical activity (Tegner score) was 5.5+/-2.1 in group A and 5.5+/-2.1 in group B before onset of the complaints. In follow-up, patients from group B (4.9+/-1.2) had a reduced Tegner score in tendency. The patients in group A had a significantly reduced level of physical activity (2.7+/-0.6). A total of 12 patients from group B had a range of motion lesser than 80 degrees in flexion. These patients underwent joint mobilization and control arthroscopy. During control arthroscopy there was always found a stable periosteal flap. Short-term clinical results with periosteal arthroplasty produced a significant reduction in pain and improved Lysholm score in comparison to abrasive arthroplasty.