Allograft Reconstruction of the Extensor Mechanism after Resection of Soft Tissue Sarcoma

A New Procedure for Reconstructing the Knee Extension Mechanism After Resection of the Knee Joint and Patella: A Case Report

CASE

We reconstructed the knee extension mechanism using a novel procedure for a 16-year-old adolescent girl with osteosarcoma that invaded her femur, patella, and patellar tendon. The knee joint was replaced with a megaprosthesis, and the extension mechanism was reconstructed using artificial ligaments sandwiched with bone cement forming a patella. At the one-year follow-up, she could walk using a knee orthosis without crutches.

CONCLUSIONS

Reconstruction of the knee extension mechanism after patellectomy remains challenging. Our new method achieved an acceptable knee function and is, therefore, useful for patients undergoing excision of the knee joint and extension mechanism.

Bilateral Extensor Mechanism Allograft Reconstruction in Native Knees: A Case Report

CASE

A 66-year-old man presented with chronic bilateral extensor mechanism dysfunction and profound patella baja after failed revision surgery for bilateral quadriceps tendon ruptures. Staged bilateral reconstruction with complete extensor mechanism allograft resulted in excellent two-year satisfaction and clinical outcomes.

CONCLUSION

Complete extensor mechanism reconstruction can be a successful treatment for chronic quadriceps tendon rupture with profound patella baja.

Wide en bloc resection of an extraskeletal myxoid chondrosarcoma about the knee with single-stage knee extensor mechanism reconstruction: A case report

Soft tissue sarcomas about the patellar tendon necessitate wide resection and thus present a significant reconstructive challenge. This article describes the novel use of a synthetic mesh graft to reconstruct the knee extensor mechanism as a single stage procedure after wide en bloc resection of an extraskeletal myxoid chondrosarcoma (EMC) in a patient with an invasive mass that was intimately associated with her patellar tendon.

Three-dimensional-printed custom-made patellar endoprosthesis for recurrent giant cell tumor of the patella: A case report and review of the literature

BACKGROUND

Giant cell tumor (GCT) is a benign lesion and rarely involves the patella. This disease is characterized by a relatively high recurrence rate after primary treatment. En bloc resection has been a predominant option for recurrent GCT. However, total patellectomy can lead to disruption of the knee. Therefore, exploration of functional reconstruction of the extensor mechanism is worthwhile.

CASE SUMMARY

A 54-year-old woman presented with right knee pain and swelling, and was diagnosed as having a GCT in the patella following curettage and autograft. Medical imaging revealed a lytic and expanded lesion involving the whole patella with focal cortical breaches and pathological fracture. Based on the combination of histological, radiological, and clinical features, a diagnosis of recurrent GCT in the patella was made (Campanacci grade III). After a multidisciplinary team discussion, three-dimensional (3D)-printed custom-made patellar endoprosthesis was performed following en bloc resection for reconstructing the extensor mechanism. The patient was followed for 35 mo postoperatively. No evidence of local recurrence, pulmonary metastasis, or osteoarthritis of the right knee was observed. The active flexion arc was 0°-120°, and no extension lag was detected. A favorable patellar tracking and height (Insall-Salvati ratio 0.93) were detected by radiography.

CONCLUSION

We depict a case of a GCT at the right patella, which was successfully treated by patellectomy and 3D-printed custom-made endoprosthetic replacement. The patella normal reconstruction, the precise-fit articular design, and gastrocnemius flap augmentation could lead to satisfactory knee function and a low rate of complications in the short-term follow-up.

Current Advances on the Regeneration of Musculoskeletal Interfaces

The regeneration of the musculoskeletal system has been widely investigated. There is now detailed knowledge about the organs composing this system. Research has also investigated the zones between individual tissues where physical, mechanical, and biochemical properties transition. However, the understanding of the regeneration of musculoskeletal interfaces is still lacking behind. Numerous disorders and injuries can degrade or damage tissue interfaces. Their inability to regenerate can delay the tissue repair and regeneration process, leading to graft instability, high morbidity, and pain. Moreover, the knowledge of the mechanism of tissue interface development is not complete. This review presents an overview of the most recent approaches of the regeneration of musculoskeletal interfaces, including the latest in vitro, preclinical, and clinical studies. Impact statement Interfaces between soft and hard tissues are ubiquitous within the body. These transition zones are crucial for joint motion, stabilisation and load transfer between tissues, but do not seem to regenerate well after injury or deterioration. The knowledge about their biology is vast, but little is known about their development. Various musculoskeletal disorders in combination with risk factors including aging and unhealthy lifestyle, can lead to local imbalances, misalignments, inflammation, pain and restricted mobility. Our manuscript reviews the current approaches taken to promote the regeneration of musculoskeletal interfaces through in vitro, pre-clinical and clinical studies.

Reconstruction of Chronic Patellar Tendon Injury with Achilles Tendon Allograft: A Case Report

CASE

There have been several methods described for the reconstruction of chronic patellar tendon injuries in the native knee. Here, we report a former athlete who sustained a tibial tubercle fracture as an adolescent and presented with functional deficits from a patellar tendon that healed in elongation after the removal of hardware and debridement of ossifications within the tendon. He underwent reconstruction with Achilles allograft.

CONCLUSIONS

Achilles tendon allograft is a good option for reconstructing chronic patellar tendon injuries. Our patient had an excellent outcome at 1 year.

Extensor Mechanism Allograft in Osteosarcoma of the Patella: A Case Report

CASE

A 24-year-old female diagnosed with fibroblastic osteosarcoma of the patella underwent a total patellectomy and surgical reconstruction with a large bone-tendon allograft of the extensor mechanism and adjuvant chemotherapy. At 5 years' postoperative, the patient has adequate disease control and excellent joint function.

CONCLUSIONS

Reconstruction with an extensor mechanism allograft is an appropriate alternative for patients with malignant patella tumors without tumor contamination of the joint, allowing for satisfactory knee function and disease control.