Functional and radiologic results of extensor mechanism reconstruction methods following proximal tibial modular endoprosthetic reconstructions: Direct versus medical textile augmented reattachment.

Abstract

Following proximal tibial resection and modular endoprosthetic reconstruction, extensor mechanism can be reconstructed with different techniques. This study compares direct reattachment (DR) with medical textile augmented reattachment (MTAR) methods in terms of functional results and radiological results. Fifty-five patients (34 male, 21 female) operated between 1990 and 2015 with a minimum follow up of 24 months in a single center were evaluated retrospectively. The median age was 18 years (range: 9-64). The reconstruction was performed via MTAR (polypropylene mesh, Trevira) in 23 patients and DR in 32 patients. Incidence and degree of extension lag, degree of flexion and development of postoperative patella alta were evaluated at 3, 6 and 24 months. The mean follow up was 78.5 months. Extension lag incidence at 24 months was 71.9% in the DR group compared with 43.5% in the MTAR group (P < 0.05).Theextensionlagratiosat 24 months in DR was 0-5° in 8.7% (n = 2), 6-10° in 21.7% (n = 5), 11-15° in 17.4% (n = 4) and > 15° in 52.2% (n = 12), respectively. Extension lag ratios at 24 months in MTAR were 0-5° in 12.5% (n = 4), 6-10° in 6.3% (n = 2), 11-15° in 6.3% (n = 2) and > 15° in 6.3% (n = 2). The mean MSTS score in DR group was 20.7 compared with 23.2 in the MTAR group (P = 0.008). MTAR is associated with a lower incidence as well as a lower degree of extension lag. The flexion range and the incidence of patella alta are not statistically different between the groups. MSTS scores of MTAR group are significantly higher than DR group at 2-year follow up.