Inferior results at long-term follow-up after extensor mechanism allograft reconstruction in septic compared to aseptic revision total knee arthroplasty.

PURPOSE: Extensor mechanism lesion after total knee arthroplasty (TKA) is a catastrophic complication. Reconstruction with extensor mechanism allograft (EMA) has been described as a sound salvage procedure. Its effectiveness at long term and in septic cases is still under scrutiny. The long-term results of EMA reconstruction for chronic extensor mechanism failures following aseptic and septic revision TKA have been analysed. METHODS: From the institutional database, 35 patients with a revision TKA (RevTKA) undergoing EMA reconstruction from 2005 to 2015 have been retrospectively identified. A history of periprosthetic joint infection (PJI) was found in 13 (37%) patients. The mean follow-up was 81.2 months (± 34.7, range 3-120). EMA failures were considered for lag more than 20°, Knee Society Score (KSS) less than 60 points, and/or in the case of revision of the allograft. RESULTS: The mean KSS improved from 35.9 (± 16.9, range 0-54) to 86.6 (± 10.4, range 54-99) points in the aseptic group (p < 0.001) and from 27.5 (± 11.6, range 10-44) to 79.4 (± 16.3, range 48-94) points in the septic group (p < 0.001). The extensor lag changed from 48.4° (± 14.5, range 30-90) to 4.6° (± 10.8, range 0-50) in the aseptic group (p < 0.001) and from 56.5° (± 20.8, range 30-90) to 6.1° (± 6.8, range 0-20) in the septic group (p < 0.001). The mean postoperative flexion was 105.2° (± 13.2, range 75-130) in the aseptic group and 102.7° (± 12.5, range 80-120) in the septic group (p = 0.32). Three failures (14% of the cases) occurred in the aseptic group and five in the septic group (38% of the cases). The overall survivorship at 10 years was 83.3% (22 cases, CI95 94.2-121.7) vs 58% (13 cases, CI95 67.2-111.7) in the aseptic and septic group, respectively (p = 0.01). CONCLUSIONS: EMA reconstruction after extensor mechanism disruptions in TKA is a reliable salvage procedure. The septic nature of the revision decreased the functionality of the knee joint after EMA, but it did not represent a risk factor for re-ruptures or recurrence of infection. LEVEL OF EVIDENCE: Level III.

Pre-operative planning in anterior cruciate ligament reconstruction revision surgery.

Primary reconstructions of the anterior cruciate ligament are common and increasing in number, a trend inevitably paralleled by an increase in the number of revision procedures. Failure of primary ACL reconstruction can appear as objective residual laxity, subjective instability, severe and persistent postoperative stiffness and/or pain, or infection. Revision surgery is a complex procedure, in which the expected clinical outcome is inferior to that which can be expected from primary reconstruction, and patients have a 5.4% risk of undergoing a second revision after five years. This type of procedure demands correct and exhaustive preoperative planning so as ensure optimal treatment of accompanying lesions and of any complications arising during surgery. It is important to know, in detail, the patient's clinical history (when the primary surgery was performed and the technique used, the cause of the recurrence, the degree of functional recovery, etc.), to perform a thorough clinical examination (to evaluate alignment, gait cycle, skin color, the trophic condition of the muscles, joint laxity), and to have available the results of a detailed and specific imaging study and also of blood tests, in order to exclude the presence of an infection.