Tibial tubercle osteotomy for patellofemoral malalignment and chondral disease provided good outcomes: A systematic review

Importance: Tibial tubercle osteotomy (TTO) is indicated to treat patellofemoral (PF) malalignment and chondral disease refractory to conservative treatment. However, there are no systematic reviews describing TTO outcomes in chondral damages without instability. Aim: The aims of this study were to (1) assess the quality of the published studies, (2) identify indication for TTO to treat PFP with chondral disease without instability, (3) evaluate the most common TTO techniques, (4) evaluate the clinical outcomes, and (5) evaluate TTO's complication and failure rates. Evidence review: In December 2020, a literature search was performed applying the following criteria: (1) peer reviewed Level 1-4 studies; (2) English language; (3) human subjects with clinical and/or radiological outcomes; (4) TTO alone or associated with minor cartilage procedure (only drilling, no instability); (5) minimum follow-up 12 months, minimum 10 patients; and (6) no more than 20% of drop-out rate. Data from studies were collected and described with weighted averages and standard deviations. Findings: A total of 18 Level 4 studies were included. The average Coleman Methodology Score was 61.5 points (range 48-81). A total of 851 patients (892 knees) were included, with 64.8% of female patients. The weighted average follow-up was 49.1 months (range 12-128.5). Indication for TTOs was poorly described. The main technique used was anteromedialisation (60.4%). In 27.7% of the cases, TTO was associated with lateral release. Different scoring systems were used to evaluate outcomes, with significant improvements. The average rate of good/excellent results was 78.7% (range 57%-100%). Fifteen studies described the complication rate (9.9%), whereas only four reported the failure rate (6.2%). Conclusion and relevance: TTOs performed to treat PF malalignment associated with chondral disease without instability provided good clinical outcomes, with acceptable complication/failure rates. However, high-level studies are necessary because of studies' heterogeneity regarding patellofemoral malalignment and chondral disease treatment. Study design and level of evidence: Systematic review. Level IV. Level of the study: Level IV, systematic review of Level IV studies.