Synovial sarcoma, which accounts for 5-10% of all soft tissue sarcomas, has a high prevalence among males (1,2). Synovial sarcoma is the most frequent soft tissue sarcoma in children and young adults, but its peak incidence occurs in the third decade of life (3,4). The most frequently affected sites are the extremities. However, synovial sarcoma can develop from serosal surfaces, such as the pleura and pericardium (4,5). Synovial sarcoma has two pathological subtypes: Monophasic and biphasic. Moreover, synovial sarcoma has unique genomic characteristics, such as the translocation t(X;18)(p12.2:q11:2) (6). The standard treatment for localized synovial sarcoma is surgical resection with adequate margins (7).

Several oncological reconstructions, such as megaprostheses or biological reconstructions using irradiation, autoclaving, pasteurization, or freezing, have been developed for the bone defects after wide excision of malignant bone or soft tissue sarcoma. Tsuchiya et al (8) developed a frozen autograft technique. In the early days of the technique, the affected bone was excised with an appropriate surgical margin. The resected bones were frozen and consecutively reconstructed with intramedullary nails or plates. Later, Shimozaki et al (9) modified this freezing method and developed a pedicle freezing method. The pedicle freezing method allows maintenance of the anatomical continuity on either the proximal or distal side. This modified pedicle freezing method may potentially achieve a higher bone union rate and limb function than those achieved with the original free-freezing method.

In this case report, we discuss the excision of a synovial sarcoma close to the elbow and the successful reconstruction with a pedicle frozen autograft involving the elbow joint. To our knowledge, this is the first reconstruction that used a pedicle frozen autograft involving the joint after the wide excision of a soft tissue tumor in the elbow.

The standard therapeutic approach for synovial sarcoma is wide surgical excision combined with neoadjuvant and adjuvant chemotherapy and/or radiotherapy (1,5,7,11). The frozen autograft technique of Tsuchiya et al (8) uses liquid nitrogen at -196˚C as the cryogenic agent to destroy tumor cells. Freezing at this extremely low temperature devitalizes tumor cells by inducing ice crystal formation and cell dehydration (12). In our case, we used the pedicle freezing method for elbow reconstruction after wide excision of a synovial sarcoma for the first time. Complete bone union of the ulnar z-graft was achieved by the seventh month after surgery, and upper extremity function was fully preserved. Although radiological signs of osteoarthritis of the elbow joint were found at the follow-up after four years, there was no joint space narrowing, and the patient was not affected in his activities of daily living.

The advantages of using frozen autografts are as follows: i) They are easy to perform; ii) They require only a short duration of treatment; iii) They fit perfectly because the anatomy remains unchanged; iv) There is no need for bone banking; v) They are easy to attach to any preserved tendons and ligaments; and vi) They achieve earlier osteogenesis do than pasteurized autografts (13,14). Zekry et al found that the five- and ten-year survival rates of frozen autografts were as high as 91.2%, and that they achieved complete bony union in 97% of patients after sarcoma or bone metastasis excision (15). Based on these findings, we chose to perform a frozen autograft in our patient to ensure bone and joint preservation.

Most descriptions of the use of frozen autografts for reconstruction after wide excision of sarcomas involve the lower extremities. There are some reports of biological reconstruction around the elbow involving free frozen autografts and flaps (16). Compared to a free frozen autograft, pedicle frozen autografts have shown a shorter bone union period and lower postoperative complication rates (9). In our case, because the sarcoma was adjacent to both the humerus and ulna, we immersed the humerus and ulna with the elbow joint in liquid nitrogen during the pedicle joint freezing to preserve the limb function. Bone union at the osteotomy site was achieved seven months after surgery, and the patient showed full elbow joint range of motion.

There are different methods described that preserve elbow function. In patients with implant use for prosthetic replacement following the resection of malignant or progressive benign tumors around the elbow, the survival rate was 64% after five years (17). However, the humeral stem loosening rate was high (17). There are several bone recycling methods, such as autoclaving, irradiation, and pasteurization. However, these techniques may cause heat- or radiation-induced bone weakness (18). Some studies involving histological examinations of these autografts found that osteogenesis occurred only slowly (13,14).

Postoperative osteoarthritis is a long-term complication of frozen autografts. A study on frozen autografts after resection of malignant bone tumors (mostly osteosarcomas) with epiphyseal involvement compared 27 patients with a mean age of 31.6 years (range 12-72 years) and a mean follow-up period of 94.0 months (range 6-217 months). They found that only 1 of 23 patients in the total epiphyseal freezing group remained osteoarticular graft survived until the final follow-up (19). The other 22 patients had developed osteoarthritic changes by the final follow-up (19). Meanwhile, all four of the patients who underwent intraepiphyseal resection for partial preservation of the healthy cartilage had excellent osteoarticular graft survival (19). However, most of the cases in their report involved lower extremity joints, and no elbow joints were described. In our patient, we observed no narrowing of the humeroulnar joint four years after the surgery. As the elbow joint is not a weight-bearing joint, osteoarthritis may progress more slowly than what has been observed in lower extremity joints.

We describe the first case of wide excision and reconstruction with pedicle freezing of the elbow joint in a patient with a monophasic fibrous synovial sarcoma. Based on our experience with this case, we consider this a promising method for reconstruction after the excision of malignant bone or soft tissue tumors around the elbow joint. More patients need to be treated and followed up to assess the complications and long-term prognosis of this method.

In conclusion, to the best of our knowledge, this is the first case of a pedicle frozen autograft involving the elbow joint following the wide excision of a soft tissue tumor. Although the reconstruction is challenging due to the complex anatomy of the elbow, pedicle joint freezing combined with in situ preparation may help to preserve the limb and the function of the elbow joint.