Tibial tuberosity-trochlear groove distance: does it measure up?

Area of Science:

• Orthopedics
• Biomechanics
• Radiology

Background:

• Patellar instability is often linked to anatomical variations like patella alta and trochlear dysplasia.
• Lateralization of the extensor mechanism is implicated, but its contribution and measurement are debated.
• The tibial tuberosity-trochlear groove (TT-TG) distance is a frequent imaging metric for assessing this lateralization.

Purpose of the Study:

• To evaluate if the TT-TG distance adequately represents the pathoanatomy of patellar instability.
• To determine if TT-TG measurements aid in surgical planning for patellar instability.

Main Methods:

• Systematic review of literature concerning TT-TG measurements and patellar instability.
• Analysis of factors influencing TT-TG measurements.
• Evaluation of surgical outcomes following procedures addressing TT-TG.

Main Results:

• The TT-TG distance is influenced by numerous factors, necessitating careful interpretation.
• Medializing tibial tubercle osteotomy may not fully correct the root anatomical issues contributing to instability.
• The sufficiency of TT-TG in summarizing complex pathoanatomy remains questionable.

Conclusions:

• The TT-TG distance alone may not fully capture the pathoanatomy of patellar instability.
• Relying solely on TT-TG for surgical planning may not address underlying anatomical problems.
• Further investigation into comprehensive assessment of patellar instability pathoanatomy is warranted.