Arthroscopic Detection of Chondral Damage in Suprapatellar Tibia Nailing: Incidence, Extent, and Clinical Relevance. A prospective study.

BACKGROUND

Suprapatellar intramedullary nailing (SP-IMN) is widely used for tibial shaft fractures due to its biomechanical and clinical advantages over infrapatellar approaches. However, concerns remain regarding potential chondral damage, with limited evidence from prospective studies. This study aims to address these gaps by evaluating the incidence of chondral damage, the presence of debris, and their effects on clinical outcomes. Specifically, we sought to answer the following questions: (1) Do clinical outcomes differ with different locations or grades of chondral damage? (2) What is the incidence of chondral damage following SP-IMN? (3) What are the characteristics of chondral damage?

HYPOTHESIS

We hypothesize that extent and anatomical location of chondral damage may influence clinical outcomes, with more severe or widely distributed injuries potentially leading to poorer clinical results.

PATIENTS AND METHODS

This prospective study included 51 patients treated with SP-IMN for tibial shaft fractures. Arthroscopic evaluations were performed pre- and post nailing to assess chondral damage. The Outerbridge classification was used to grade chondral injuries. Clinical outcomes were assessed at 3, 6, and 12 months postoperatively using Lysholm scores, Visual Analog Scale (VAS) scores, anterior weight-bearing test (AWT-K) ratio, and range of motion (ROM).

RESULTS

Chondral damage was observed in 70% of cases, with Outerbridge Grade 1 injuries being the most common (35%). Metallic debris was identified in 57% of cases, predominantly localized in Hoffa's fat pad. Neither chondral damage nor metallic debris significantly affected clinical outcomes, including Lysholm scores, VAS scores, AWT-K ratio, or ROM. Significant improvements in these clinical measures were observed over time for all patients, irrespective of intra-articular findings.

CONCLUSION

SP-IMN is an effective technique for tibial shaft fractures, with a high incidence of chondral damage and metallic debris but no significant adverse impact on clinical outcomes. Further studies are warranted to explore the long-term effects of metallic debris and refine surgical techniques to minimize intra-articular injuries.

LEVEL OF EVIDENCE III

Single cohort prospective study.