J Orthop Trauma. 2025 Oct 14. doi: 10.1097/BOT.0000000000003098. Online ahead of print.
ABSTRACT
OBJECTIVES: To compare the incidence and severity of patellofemoral chondromalacia and its correlation with anterior knee pain following suprapatellar (SP) versus infrapatellar (IP) approaches for tibial intramedullary nailing.
METHODS: Design: Prospective, randomized controlled trial.
SETTING: Single-center study at a Level I Trauma Center.
PATIENT SELECTION CRITERIA: Patients aged between 18-45 years who presented with AO/OTA type 42 fractures from September 2020 to March 2024 were randomized into Suprapatellar (SP) and Infrapatellar (IP) groups. MRI at six months post-surgery assessed cartilage damage using the Modified Outerbridge Classification. Diagnostic knee arthroscopy was offered for further evaluation.
OUTCOME MEASURES AND COMPARISONS: The primary outcome was frequency and severity of chondromalacia assessed via MRI (Modified Outerbridge Classification) and diagnostic knee arthroscopy at six months. Secondary outcomes were correlation of MRI findings with knee pain (VAS score) and comparison of time taken for nail insertion with cartilage damage in the SP group.
RESULTS: Both groups had 30 patients each. In SP group, mean age was 33.7 years (range 18-45 years) and 83.3% were male while IP group had a mean age of 29.3 years (range 18-45 years) and 83.3% were male. 57 underwent MRI knee (SP: 28, IP: 29) and 16 underwent diagnostic knee arthroscopy (SP: 9, IP: 7). MRI detected chondromalacia in 46.4% in the SP group and 44.8% patients in the IP group; there was no significant difference (p-value 0.9). Arthroscopy revealed chondromalacia in all 9 (100%) patients who underwent diagnostic arthroscopy in the SP group as compared to 2 of 7 (28.6%) patients in the IP group (p-value 0.003). Correlation between chondromalacia grading on MRI and VAS scores at 6 months follow-up was significant (r=0.4, p-value 0.006). Time taken for nail insertion weakly correlated with presence of chondromalacia on MRI in the SP group but was not statistically significant (r=0.2, p-value 0.5).
CONCLUSIONS: No differences were found in the occurrence of patellofemoral chondromalacia seen on MRI between SP or IP nailing techniques. The SP approach demonstrated a higher frequency of patellofemoral chondromalacia on arthroscopic evaluation.
LEVEL OF EVIDENCE: Therapeutic Level I.
PMID:41092396 | DOI:10.1097/BOT.0000000000003098
