The effect of the Pie Crust Method on bone incisions in patients with varusgonarthrosis undergoing total knee arthroplasty

Aim: In this study, the effect of the pie crust method applied intraoperatively to the medial collateral ligament in patients with varus gonarthrosis on the correction of varus deformity and the bone cuts was investigated. Materials and Method: Twenty-eight patients with varus gonarthrosis who underwent surgery at Harran University Faculty of Medicine Research and Practice Hospital between October 2024 and August 2025 were prospectively evaluated. Patients with valgus gonarthrosis were excluded from the study. Axis measurements were made using two separate fluoroscopy images taken during surgery. The first fluoroscopy image was taken before the pie crust method was applied. The second fluoroscopy image was recorded after the pie crust method. A comparison was made between the axis measurements in these two fluoroscopy images. The angle changes in knee varus deformity after the pie crust method and its effect on reducing the amount of bone cuts were indirectly investigated. Results: The total number of patients participating in the study was 28. Twenty-seven (96.43%) of the patients were female and one (3.57%) was male. The mean age was 66.14±8.15 years, with the youngest patient being 47 and the oldest being 81 years old. The mean BMI of the patients was 27.35±1.99. In addition, 18 (66.7%) of the patients were overweight, 6 (22.2%) were normal, and 3 (11.1%) were in the overweight-obese category. The normal distribution of the patients' age, gender, and BMI values was examined. There was a statistically significant difference (p=0.000) between the ages of the patients (p<0.05). Of the 18 female patients, 17 underwent ligament-sparing surgery and 10 underwent ligament-cutting surgery. One male patient underwent ligament-sparing surgery. No statistical difference (p=0.141) was found between genders according to ligament-cutting and ligament-preserving methods (p>0.05). In the ligament preserving group, 6 were detected on the left and 12 on the right side, and in the ligament severing group, 4 were detected on the left and 6 on the right side. When the axis measurement value ranges of the patients before the operation, during the operation, and during the recovery period were examined, it was seen that the axis values of all patients before the operation were between - xii 21 and 0. In the first measurement during the operation (INTRAOP_AKS1), 21.43% (n=6) of the patients had 0.1–2, 35.71% (n=10) had 2.1–4, and 42.86% (n=12) had 4.1–20. In the second measurement during the operation (INTRAOP_AKS2), 11.12% (n=3) of the patients had 0.1–2, 14.81% (n=4) had 2.1–4, and 74.07% (n=20) had 4.1–20. In the postoperative period, ACS values were found to be between 0.1 and 2 in 3.57% (n=1), 2.1 and 4 in 21.43% (n=6), and 4.1 and 20 in 75% (n=21) of the patients. When the axis values of the patients' intraoperative fluoroscopy were compared, the effect of the pie crust method on correcting varus deformity was measured as +2.09 degrees. When the intraoperative fluoroscopy and postoperative axis values of the patients were compared, the effect of the pie crust method on correcting the varus deformity was measured as +1.55 degrees on average. As a complication, one patient developed a partial midline MCL rupture during the pie crust method. The patient was scheduled for a total knee replacement with posterior cruciate ligament transection and had PCL instability. This suggests that the pie crust method should be performed with greater caution in patients with PCL instability. The complication rate was 3.57% (1 patient). The complication rate (p=0.00) was statistically significant (p<0.05). Conclusion: When performed by experienced surgeons and with appropriate patient selection, the pie crust technique is considered an effective technique for correcting varus deformity in total knee arthroplasty, resulting in fewer bone cuts. The pie crust technique not only offers a less invasive approach but also accelerates postoperative recovery, resulting in lower complication rates and better functional outcomes. These findings suggest that the pie crust technique can be considered a safe and effective soft tissue release method in total knee arthroplasty. The effectiveness of the technique is operator-dependent and requires careful standardization.