RESUMEN
Historically, the shoulder arthroplasty humeral component has been designed for the management of infections, tumours and fractures. In all these cases the stem was needed as a scaffold. Original humeral components were not developed for use in shoulder arthritis, so these designs and derivates had a long stem. The newest humeral implants innovations consist in shortening of the implant, or even removing the whole stem, to rely on stemless fixation at the level of the metaphysis. This implies the advantages of preserved bone stock, less stress shielding, eliminating the diaphyseal stress riser, easier implant removal at revision, and humeral component placement independent from the humeral diaphyseal axis. Nowadays, surgeons try to balance the need for a stable fixation of the humeral component with the potential need for revision surgery. Complications of revision shoulder arthroplasty are related to the need for removing a well-fixed humeral stem, the length of the procedure, and the need to treat severe bone loss.
RESUMEN
INTRODUCTION: Full-thickness chondral defects at the knee joint predispose to the beginning of a degenerative process which final consequence is the compartment collapse and finally the deviation to varus, because the cartilage of the medial femoral condyle is the most frequently affected area. Likewise, people with these chondral defects are more likely to develop tricompartmental osteoarthritis, reason why early surgical management should be the treatment of choice. The aim of this study was to compare the pre- and post-operative lower limb alignment (mechanical axis), in cases of full-thickness chondral defects of the femoral medial condyle that have been managed by means of a prosthetic focal inlay resurfacing, at a minimum follow-up of five years. METHODS: A retrospective study of patients treated for chondral defects in the medial femoral condyle was performed. The inclusion criteria were patients who had undergone a focal inlay resurfacing and minimum follow-up of 5 years. Patients that required a concomitant valguizing tibial osteotomy were finally excluded. The follow-up analysis was performed by means of radiological examinations performed prior to surgery and at the last follow-up visit. The mean limb mechanical axis of the operated knees was calculated both pre- and post-operatively, and comparisons between these two settings were performed. RESULTS: Ten patients were included: eight men and two women. The mean age at the time of surgery was 55 (40-65) years. The mean follow-up was 9 years (range 5-15). The mean limb mechanical axis was 1.33 ± 4.16 in the pre-operative setting and 2.40 ± 5.50 in the post-operative setting (p = 0.441). CONCLUSION: In the setting of small to moderate size, unique femoral medial condyle full-thickness chondral lesions, filling the defect with an inlay prosthetic resurfacing may protect against the progression to varus deformity. LEVEL OF EVIDENCE: Therapeutic case series, Level IV.
