Locking plates versus retrograde intramedullary nails in the treatment of periprosthetic supracondylar knee fractures. A retrospective multicenter comparative study.

INTRODUCTION

Biomechanical studies demonstrated the superiority of retrograde supracondylar intramedullary nails (RIN) against locking plates (LP) for the treatment of periprosthetic supracondylar femoral fractures (PSFs); however, clinical results are still conflicting. This study aimed to compare LP and RIN, as well as, cemented and uncemented nails in the treatment of PSFs regarding fracture healing, complications and functional results.

MATERIALS AND

METHODS

A retrospective multicenter analysis of 60 PSFs classified as Rorabeck type I or II was performed. Thirty-one cases were treated with LP while in 29 cases RIN were used. Out of the latter, 14 had nailed cementoplasty, while 15 an uncemented nail.

RESULTS

The two groups were comparable concerning gender, ASA score, operated side, follow-up time, fracture type and mechanism of injury. The LP was significantly younger than the RIN group. Forty-six cases had fracture union at an average of six months, 11 were healed between seven and twelve months (delayed unions), and three developed non-unions. There was no significant difference in the median union time between RIN and LP groups (six vs five months, p = 0.707) or cemented and uncemented nailing groups (5.5 vs six months, p = 0.354). The RIN group had fewer delayed unions or non-unions than LP group; however, not reaching significance (4 vs 10, p = 0.190). Complications were fewer but non-significantly different between cemented and uncemented nails (one vs five, p = 0.481). The mean postoperative flexion was comparable between RIN and LP groups (99.1° vs 94.9°, p = 0.547) or cemented and uncemented nails (102° vs 96.3°, p = 0.4). The mean Oxford Knee Score did not differ between LP and RIN groups (30.8 vs 31.3, p = 0.93) as well as between cemented and uncemented nails (31.5 vs 30.6, p = 0.801).

DISCUSSION: PSFs with good bone stock can be treated equally with LP or RIN. Nails demonstrated advantages concerning the fracture healing potential. Orthopaedic surgeons need to be trained in both treatment options to manage PSFs. Cemented nails may increase stability and healing capacity in elderly osteoporotic patients; however, further studies are needed.