Introduction: Cryosurgery of bone tumors using direct pour of liquid nitrogen has the advantage of joint preservation associated with good local tumor control. However, this technique does not allow accurate control of the temperature or of the overall time of freezing. Additionally, this is a gravity-dependent procedure that cannot be applied in all shapes and locations of tumor cavities. The authors report their experience with a novel cryosurgical technique that allows accurate determination of the temperature and freezing time as well as freezing of any geometry of tumor cavity.

Materials and Methods: From 1997 to 2000, 58 patients who were diagnosed with 13 malignant and 45 benign-aggressive bone tumors underwent argon-based cryoablation. This technique included tumor removal by means of curettage and burr-drilling, filling the tumor cavity with a gel medium, insertion of metal probes into this medium, and computer-controlled delivery of argon gas through the metal probes, and reconstruction of the tumor cavity with cemented hardware. All patients were followed for more than two years.

Results: None had skin necrosis, infection, thromboembolic complication, or neurapraxia. Fractures occurred in two patients (3.4%) and local tumor recurrence in two patients (3.4%), who were successfully treated with a second closed cryoablation.

Conclusions: The current study focuses on the concept and surgical technique of argon-based and computer-controlled, closed cryoablation of bone tumors. The main advantages of this system are the ability to control the freezing temperature and overall freezing time and the use of a gel medium, which evenly conducts the cold temperature throughout the tumor cavity and allows cryoablation of various cavital geometry and positions. The current technique of argon-based cryoablation is simple and easy to perform. It achieves good local tumor control and is associated with a low rate of complication. The authors recommend its use as an alternative to the traditional direct pour technique of cryosurgery.

Introduction: Diffused pigmented villonodular synovitis (PVNS) is a locally aggressive lesion for which surgery provides only marginal resection. An adjuvant treatment modality is therefore required to prevent local tumor recurrence. The authors describe their experience with intra-articular injection of Yttrium⁹⁰ (Y⁹⁰), a radioisotope, as an adjuvant for tumor resection.

Materials and Methods: Between 1989 and 2002, 20 patients with diffuse PVNS were treated with post-operative, intraarticular injection of Y⁹⁰. There were 15 male and 5 female patients who ranged in age from 13 to 67 years (mean, 35 years). Anatomic locations of the affected joints included: knee – 15, ankle – 4, hip – 1. Tumor resection was initially done in all patients: 13 patients required open arthrotomy, the remaining 7 underwent arthroscopic tumor resection. Ten patients were referred for treatment after having operation for a local tumor recurrence: 6 patients had one, 2 had two, 1 had three, and the remaining one had five local recurrences. Six to eight weeks after surgery, intraarticular injection of 15–25 mCi of Y⁹⁰ was done. These procedures were conducted in the operating room under local anesthesia and fluoroscopic guidance. All patients were followed for a minimum of two years (range, 25–168 months; mean, 65 months).

Results: Following Y⁹⁰ injection, all patients reported mild pain around the affected joint. This pain was well controlled with the use of NSAID’s and typically resolved within a few days or weeks. Three patients had superficial skin inflammation and associated blisters around the site of injection, probably the result of Y⁹⁰ effect on the soft-tissues. All were treated conservatively with complete resolution of their symptoms. All patients gained their pre-injection range-of-motion within 4–6 weeks. At the most recent follow-up, five patients had transient post-radiation skin changes (discoloration of the skin and dry and scaly skin) and local recurrence occurred in only one patient (5%) with PVNS around the knee; additional Y⁹⁰ injections were unsuccessful and he eventually underwent knee arthrodesis.

Conclusion: Y⁹⁰ injection is a reliable adjuvant for surgery in the management of diffused PVNS. Local tumor control and good function, associated with only mild morbidity are achieved in the majority of the patients.

Introduction: Megaprosthetic failures around the knee and especially those who are infection-related are difficult to manage. Although most of these cases are effectively managed with a two-stage prosthetic revision, selected cases eventually require sacrifice of the knee joint. The authors present their experience with knee-arthrodesis using a vascularized fibula and allograft reinforcement.

Materials and Methods: Between 1998 and 2002, eight patients with failed knee prosthesis were referred for resection-arthrodesis; all patients had at least two previous revision attempts using a spacer or a new implant. Knee-arthrodesis included resection of the distal femur and proximal tibia and reconstruction with a free micro-vascularized fibular graft and allograft reinforcement. Fibular grafts were harvested with a large musculocutaneous flap to facilitate soft-tissue coverage and monitor flap viability. Following surgery, patients were kept non-weight-bearing for 3 months. Radiographs were performed 6 and 12 weeks postoperatively to establish fibular graft incorporation. If healing had progressed satisfactorily, weight-bearing was gradually allowed.

Results: At the most recent follow-up’ all eight patients had a stable and painless reconstruction, associated with radiological evidence of solid fibular graft union. The latter was typically observed between 6 to 12 weeks from surgery. Complications included one emergent surgery for anastamotic rupture in one patient and surgical debridement with skin grafting of musculocutaneous flap necrosis in another patient.

Conclusions: Knee-arthrodesis using microvascularized fibula and allograft reinforcement is a safe and reliable salvage procedure in end-stage failures of megaprosthetic knee implants.