Objective To compare the effectiveness of the traditional center of tibial plateau as the entry point and digital technology in the design of intramedullary tibial nail point positioning method in total knee arthroplasty (TKA). Methods Between October 2011 and October 2012, 60 cases undergoing unilateral TKA and meeting the selection criteria were randomly divided into 2 groups: in group A (30 cases), the tibial plateau center as the entry point of tibial intramedullary positioning was used; in group B (30 cases), Mimics 10.01 software to simulate the guide rod point of tibial intramedullary positioning was used. There was no significant difference in gender, age, etiology, disease duration, sides, and preoperative knee range of motion, Hospital for Special Surgery (HSS) score, and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) between 2 groups (P gt; 0.05). Postoperative X-ray films were taken to measure the tibiofemoral angle and tibial angle; knee range of motion, and HSS and WOMAC scores were used to assess the activity of knee. Results The entry point of group B was located in front of the center of tibial plateau, which was inconsistent with the traditional entry point. The incision healed by first intention in all patients of 2 groups. The patients were followed up 6 to 12 months (mean, 8.6 months). The X-ray measurement at 1 week after operation showed no significant difference in tibiofemoral angle between 2 groups (t= — 6.65, P=0.72), but the anteroposterior and lateral tibial angles of group A were significantly lower than those of group B (P lt; 0.05). The knee range of motion, HSS score, and WOMAC score of 2 groups were significantly higher at 3 and 6 months after operation when compared with preoperative values (P lt; 0.05), and the values at 6 months were significantly increased than those at 3 months after operation (P lt; 0.05). HSS score and WOMAC score had no significant difference between 2 groups at 3 months after operation (P gt; 0.05), but the scores of group B were significantly higher than those of group A at 6 months (P lt; 0.05). The knee range of motion of group B was significantly better than that of group A at 3 months after operation (t=2.13, P=0.04), but no significant difference was found between 2 groups at 6 months (t=0.58, P=0.56). Conclusion Compared with the traditional intramedullary guide rod insertion point positioning, digital individualized design of entry point positioning has the advantages of more accurate lower limb force line, better recovery of knee function, and earlier 90°activities, but the long-term effectiveness needs further observation.
ObjectiveTo analyze the effectiveness of unicompartment allografts replacement for reconstructing bone defect after bone tumor resection around knee.MethodsBetween January 2007 and January 2014, a total of 9 patients received unicompartment allografts replacement to treat bone tumor around the knee, including 6 males and 3 females, with an average age of 25.8 years (range, 17-38 years). There were 7 patients with bone giant cell tumor (postoperative recurrence of bone giant cell tumor in 1 case) and 2 patients with chondromyxoid fibroma. The tumors were located at the distal femur in 7 cases and proximal tibia in 2 cases, and the tumors were almost at the lateral limbs. The symptom duration was 2-5 months (mean, 3.2 months). The size of lesion ranged from 6 cm×2 cm to 9 cm×4 cm by X-ray film and MRI; and the metastasis was excluded by CT. The length of the allograft was 8.0-9.2 cm (mean, 8.6 cm).ResultsThe intraoperative blood loss volume was 400-550 mL (mean, 480 mL); and 0-3 U of erythrocyte was transfused after operation. The continuous exudate of incision occurred in 1 patient, and cured after 3 months; the other incisions healed primarily at 2 weeks after operation. All patients were followed up 3-10 years (mean, 6 years). No operation area infection, allograft bone poor healing or rupture was found. At 1 year after operation, the knee range of motion was 90-110° (mean, 100°); the Musculoskeletal Tumor Society score was 24-29 (mean, 26). Low density area (osteolysis) was found in 6 allografts; no articular surface collapse, hairline fracture, or fracture was found in patients; callus formation was observed in the contact surface between the allograft and the host bone, and the cortical bone showed good continuity.ConclusionUnicompartment allografts replacement can provide good support and function in terms of bone tumor resection, and achieve good effectiveness by biological reconstruction.
Objective To investigate the effectiveness of complete resection of bone tumor in pelvic zone Ⅱ and reconstruction with allogeneic pelvis, modular prosthesis, and three-dimensional (3D) printing prosthesis. Methods The clinical data of 13 patients with primary bone tumor in pelvic zone Ⅱ who underwent tumor resection and acetabular reconstruction between March 2011 and March 2022 were retrospectively analyzed. There were 4 males and 9 females with an average age of 39.0 years ranging from 16 to 59 years. There were 4 cases of giant cell tumor, 5 cases of chondrosarcoma, 2 cases of osteosarcoma, and 2 cases of Ewing sarcoma. The Enneking classification of pelvic tumors showed that 4 cases involved zone Ⅱ, 4 cases involved zone Ⅰ and zone Ⅱ, and 5 cases involved zone Ⅱ and zone Ⅲ. The disease duration ranged from 1 to 24 months, with an average of 9.5 months. The patients were followed up to observe the recurrence and metastasis of the tumor, and the imaging examination was performed to observe the status of implant in place, fracture, bone resorption, bone nonunion, and so on. The improvement of hip pain was evaluated by visual analogue scale (VAS) score before operation and at 1 week after operation, and the recovery of hip function was evaluated according to the Musculoskeletal Tumor Society (MSTS) scoring system after operation. Results The operation time was 4-7 hours, with an average of 4.6 hours; the intraoperative blood loss ranged from 800 to 1 600 mL, with an average of 1 200.0 mL. There was no reoperation or death after operation. All patients were followed up 9-60 months (mean, 33.5 months). No tumor metastasis was found in 4 patients receiving chemotherapy during follow-up. Postoperative wound infection occurred in 1 case, and prosthesis dislocation occurred in 1 case at 1 month after prosthesis replacement. One case of giant cell tumor recurred at 12 months after operation, and the puncture biopsy showed malignant transformation of giant cell tumor, and hemipelvic amputation was performed. The postoperative hip pain significantly relieved, and the VAS score was 6.1±0.9 at 1 week after operation, which was significantly different from the preoperative score (8.2±1.3) (t=9.699, P<0.001). At 12 months after operation, the MSTS score was 23.0±2.1, including 22.8±2.1 for patients with allogenic pelvis reconstruction and 23.3±2.3 for patients with prosthsis reconstruction. There was no significant difference in the MSTS score between the two reconstruction methods (t=0.450, P=0.516). At last follow-up, 5 patients could walk with cane assistance and 7 patients could walk without cane assistance. Conclusion The resection and reconstruction of primary bone tumor in pelvic zone Ⅱ can obtain satisfactory hip function, and the interface of allogeneic pelvis and 3D printing prosthesis have better bone ingrowth, which is more in line with the requirements of biomechanics and biological reconstruction. However, pelvis reconstruction is difficult, the patient’s condition should be evaluated comprehensively before operation, and the long-term effectiveness needs further follow-up.