Discussion

Combined tibial tubercle fracture and patellar tendon rupture is a rare but clinically important injury pattern in adolescents. Available literature remains limited to isolated reports and small series [2,3,6-11]. In our series, all three patients were adolescent boys with acute extensor mechanism insufficiency, and two showed complete rotational displacement of the tibial tubercle fragment on the initial radiograph.

A plausible mechanism is a sudden eccentric quadriceps contraction against a flexed knee or fixed foot, producing avulsion of the tibial tubercle in the immature skeleton [3]. When the fragment rotates while remaining partially constrained by soft tissues, it may act as a fulcrum that increases tension on the distal patellar tendon and contributes to rupture. This concept is consistent with the pattern observed in our first two cases and with prior reports of bifocal extensor mechanism injury [2,5].

From a diagnostic standpoint, our findings support careful assessment of standard radiographs. In two patients, complete fragment rotation was visible on the initial lateral radiograph and raised suspicion for associated patellar tendon injury. However, because this finding was absent in our third patient and no comparison group was available, complete fragment rotation should be considered a potential radiographic clue rather than a validated diagnostic sign. Larger studies are needed to determine its diagnostic accuracy. When uncertainty persists, advanced imaging may still help define the full extent of soft-tissue injury and assist with surgical planning [2,5].

There is no universally accepted fixation construct for this lesion. Reported options include transosseous sutures, screw fixation, suture anchors, and augmentation in selected cases [4,7,8]. In our series, all patients underwent single-stage surgical treatment addressing both the osseous and tendinous components. Although fixation details varied among cases, all three patients recovered full active extension, had high Lysholm scores, and returned to their preinjury or higher activity level without complications.

Our findings are consistent with previous case reports and small case series describing favorable outcomes after prompt recognition and single-stage surgical repair of both the osseous and tendinous injuries [2,6-11]. Similar to prior reports, all patients in our series recovered full active knee extension and returned to their previous level of activity. The present series also highlights complete rotational displacement of the tibial tubercle fragment as a potentially useful radiographic clue that warrants further investigation in larger comparative studies.

This study has limitations. The cohort is small, reflecting the rarity of the condition, and the study is retrospective and descriptive. Nonetheless, all three patients had follow-up beyond one year, ranging from 14 to 27 months, which strengthens assessment of early functional recovery.