Aims. Reconstruction of soft tissues and preservation of the extensor mechanism integrity provide a major challenge following resection of the proximal tibia tumours. We propose a novel surgical technique for neopatellar ligament reconstruction using hamstring tendon in proximal tibia tumour cases. This study details the surgical technique, early clinical and radiological outcomes, and the potential long-term benefits of this innovative reconstructive approach following proximal tibia megaprosthesis implantation. Methods. This study included 15 patients with proximal tibia tumours treated at orthopaedic oncology unit in Gujarat Cancer and Research Institue (GCRI), Ahmedabad, India. Surgical procedures included resecting the proximal tibia tumour, implanting a megaprosthesis, and using hamstring tendons to reconstruct the extensor mechanism by the neopatellar ligament. Autologous hamstring tendons (gracilis and semitendinosus) harvested from the ipsilateral leg were used and these tendons were braided together with a nonabsorbable suture and threaded through the remaining patellar tendon. The braided tendons were then secured to the holes in the tibial tuberosity of the proximal tibia megaprosthesis implant XLO (Ortho Life Systems, India) using nonabsorbable fibre wire sutures FiberWire (Arthrex, USA). The tension in the tendons was optimized and the sutures were tightened with the knee in full extension and the implant with neopatellar ligament were covered by medial gastrocnemius muscle flap. The mean follow-up period was 19 months (13 to 24), the mean age of the study group was 24.6 years (14 to 44), and it included 11 males and four females. Results. The histopathological diagnosis was osteosarcoma (eight patients), Ewing’s sarcoma (four patients), and giant cell tumours (three patients). The mean surgical duration was 3.2 hours (2.5 to 4.2) and the mean blood loss was 250 ml (150 to 450).Wound infection was found in three cases, which was managed with debridement and antibiotics. None of the patients had a local recurrence at the latest follow-up. The mean active knee flexion was 92° (85° to 105°), with an extensor lag of 4.6° (0° to 10°). The mean patella height preoperatively was 4.5 cm (4.3 to 5.1), with a patella tendon length of 4.7 cm (4.3 to 5.68). The mean preoperative patella height-to-patella tendon length ratio was 0.96 (0.89 to 1.02). Postoperatively (at 12 months), the mean patella tendon length was 4.4 cm (4.1 to 5.1), with a patella height-to- patella tendon length ratio of 1.04 (1 to 1.14). Follow-up radiological examinations showed that the neopatellar tendon had integrated satisfactorily, with no obvious signs of graft rupture or elongation.The mean Musculoskeletal Tumor Society score was 24 (22 to 27). Conclusion. This study presents Salunke’s Gujarat Cancer and Research Institute (GCRI) novel approach using hamstring tendons for neopatellar ligament reconstruction in proximal tibia megaprosthesis which successfully restores the knee's extensor mechanism. This technique provides an effective reconstructive option and preserving flexion, extension, and minimizing extensor lag. Additionally, the surgical steps are easily reproducible. Early radiological evaluations in this study demonstrated no evidence of patella alta or baja, though long-term follow-up is recommended. Cite this article: Bone Jt Open 2025;6(3):342–351