Combined percutaneous medial column support screw with lateral LISS plate for the treatment of osteoporotic AO/OTA type 33C2 distal femoral fractures in the elderly

Introduction Surgical treatment is generally used for elderly patients with osteoporotic AO/OTA 33C2 distal femoral fractures, while the choice of internal fixation is controversial. Some patients have varus deformity after long-term internal fixation with lateral LISS plate, which seriously affects daily life. Therefore, in this study, we investigated the effect of the addition of percutaneous medial column support screws (PMCSS) on the prognosis of patients. Methods The medical records of 89 elderly patients with AO/OTA type 33C2 osteoporotic distal femoral fractures treated in our hospital from January 2021 to December 2022 were retrospectively analyzed. Among them, 37 patients were treated with PMCSS combined with lateral LISS plate (PMCSS-LISS group), and 52 patients were treated with lateral LISS plate alone (LISS group). The hospitalization time, operation related indicators, weight-bearing time, callus formation time, fracture healing time, and related complications were compared between the two groups. The modified radiological union scale for tibia (mRUST), the hospital for special surgery knee score (HSS), the short-from-36 health survey (SF-36) and the numerical rating scale (NRS) at each follow-up point were compared between the two groups. Results Compared with the LISS group, the PMCSS-LISS group had shorter postoperative hospital stay, earlier weight-bearing time, shorter time for callus formation and complete fracture union ( P >0.05). The mRUST scores (3 months, 6 months) and the HSS scores (1 months, 3 months, 6 months) of PMCSS-LISS group were higher compared to the LISS group ( P <0.05). At the last follow-up, the SF-36 scale was used to evaluate the quality of life. The scores of “physical functioning”, “bodily pain”, “general health perceptions”, “vitality” and “general mental health” were higher in PMCSS-LISS group than the LISS group ( P <0.05). In terms of complications, the incidence of joint stiffness and varus deformity in LISS group was higher than that in the LISS-mPMCSS group ( P <0.05). Conclusions This study confirmed that the lateral LISS plate combined with PMCSS is an effective method for internal fixation of type C2 distal femoral fractures. It shortens postoperative hospital stay, promotes fracture healing, and allows early initiation of weight-bearing exercises without increasing operation time or intraoperative blood loss. Patients achieve high mid-term knee function scores and long-term quality of life scores, making this approach worthy of clinical application. Trial registration The trial was registered in the China Trial Registry (ChiCTR2500097085).