Abstract

Introduction and Aims: Limb salvage surgery for the pediatric patient poses unique surgical challenges for the orthopaedic oncologist. In the past, surgeons have advocated amputation or rotationplasty as treatment for the skeletally immature child with a malignant bone tumor that involves a major growth plate and has an expected limb length discrepancy.

Method: The Repiphysis is a non-invasively expandable prosthesis. Applications for the knee joint are approved and other joints are pending. The expansion principle involves energy stored in a spring compressed by a locking system. Lengthenings are achieved via exposure to an electromagnetic field that allows controlled release of the spring and can be done without general anesthesia. Numerous small expansions (5–10mm) keep pace as the child grows. Between 1998–2002, 25 prostheses [knee (19), shoulder (five), hip (one)] were implanted in 21 patients. Most were implanted at the time of tumor resection and nine were revisions from previous reconstruction or fusion.

Results: Ninety lengthenings were performed with all but two on an outpatient basis. An average of 5mm was obtained per lengthening (range 1–35mm). The average follow-up was 25 months (range 12–48 months) and the latest Musculoskeletal Tumor Society functional scores averaged 87%. Eight revisions were required for mechanical problems or stem loosening. There was one amputation caused by post-operative arterial thrombosis.

Conclusion: This unique prosthesis offers many benefits in maintaining limb-length equality in growing patients. We are optimistic that this technology will prove beneficial to patients with malignant bone tumors as well as patients requiring serial limb lengthening or those with spinal deformities.

Introduction and Aims: The delivery of local antibiotics from a biodegradable implant for orthopedic infections is an attractive alternative. The implant delivers high tissue levels of antibiotic, obliterates dead space, aides in bone repair and does not require removal. This is a review of our clinical experience with custom-made calcium sulfate antibiotic implants (Osteoset BVF®, Wright Medical Technology, Arlington, TN).

Method: Between 12/1996 and 1/2003, 156 procedures using biodegradable beads for orthopaedic infections were performed. Two patients were lost to follow-up. One elderly patient died from post-operative respiratory failure. One patient was lost to follow-up. There were 154 procedures in the analysis group performed on 145 patients (55 female: 90 male). The average age of the population was 45 years (1–85 years). The inclusion in the study required that a patient have an orthopedic infection (osteomyelitis/septic arthritis), which was either biopsy- or culture-proven. The population included 36 patients with a failed arthroplasty, 41 infected nonunions, 50 patients with chronic osteomyelitis, and 27 patients with acute or post-operative bone infections. Patients were treated initially with surgical debridement and insertion of calcium sulfate beads with either Tobramycin and/or Vancomycin. All patients received oral antibiotics or intravenous antibiotics.

Results: Length of follow-up averaged 17 months (six to 67 months). Of the 154 patients, 142 became free of infection (92%). Five patients required multiple surgical procedures involving beads and further debridement to obtain an infection-free status. Many of these patients had an initial attempt at retaining a metal arthroplasty in an initial septic situation. In those patients, infection control required removal of the foreign material. Complete implant degradation occurred in all cases. Five patients had an episode post-operatively of early wound drainage, which was treated with sterile dressing changes while on intravenous antibiotics. In all patients the drainage ceased and the patients did not require further surgery.

Conclusion: Biodegradable calcium sulfate antibiotic implants, along with adjunctive antibiotics, controlled a variety of infections, obliterated dead space and aided in bone repair. Subsequent bone grafting was not required for intramedullary defects due to the osteoconductive properties of calcium sulfate. Biodegradable antibiotic beads appear effective in controlling localised orthopedic infections and do not require a second procedure for removal.

Introduction and Aims: Orthopaedic oncologists are often consulted regarding problems involving salvage of the distal femur due to bone loss, non-unions, infections. In young patients, extensive bony reconstruction is often necessary; in elderly, low demand patients, replacement with an endoprosthetic device results in decreased surgical time and more rapid mobilisation.

Method: Since 1991, 27 patients underwent reconstruction with a custom modular distal femoral replacement and rotating hinged knee joint (DFR). Twenty-two (81%) were revised to a DFR from an existing knee arthroplasty. Diagnoses included fracture, non-union, osteomyelitis, osteolysis or deformity. Average age was 66 (25–85); 83% were female. Most patients had undergone multiple prior surgeries. Patients with a history of infection had undergone aggressive resection and insertion of spacers with prolonged antibiotic administration, however they had no infection at the time of DFR reconstruction. All endoprostheses were cemented. Patients were allowed immediate weight-bearing and rehabilitation similar to patients undergoing TKA.

Results: One elderly patient died in the immediate peri-operative period of respiratory failure and one was lost to follow-up after placement in a nursing home. Average follow-up on 25 evaluable patients was 47 months (7–122). Reoperations were for recurrent infection (six) and tibial component loosening (three). Five of the six with infection were treated with synovectomy, antibiotic beads and suppressive oral antibiotics, and all five devices are still in place at an average of 54 months (range, 25–100). One severely diabetic patient had had multiple episodes of sepsis unrelated to the prosthesis which eventually seeded the distal femur and required a hip disarticulation. MSTS functional scores at last follow-up averaged 49% (13–80%) and HSS knee scores averaged 71% (37–90%).

Conclusion: DFR is a useful salvage procedure in low demand patients. Initially, six patients were scheduled for transfemoral amputation and three were confined to wheelchairs. Patients other than the hip disarticulation were at minimum household ambulators at last follow-up. In spite of problems with infection, most patients improved in overall function.