BACKGROUND: Periprosthetic infections pose a devastating complication in skeletally immature patients treated for an orthopaedic oncological condition. Reconstructive approaches to revision procedures are often limited, and many cases still require amputation. CASE PRESENTATION: In this report, we present our unique experience with the bio-expandable MUTARS® BioXpand prosthesis, utilized during the second stage of a revision surgery in an adolescent female patient. Initially, the patient underwent reconstruction using a conventional endoprosthesis following the resection of a high-grade distal femur osteosarcoma; however, she developed a deep infection six months later. During a two-stage revision procedure, the infection was successfully eradicated at the cost of loss of growth potential at also the site of proximal tibia. The initial 5 cm limb-length discrepancy was restored through the application of bioexpandable endoprosthesis, which allowed for an 8 cm gain in bone stock. At the last follow-up appointment, the patient was fully weight-bearing and demonstrated excellent clinical outcomes, with no evidence of infection or tumor recurrence. CONCLUSION: This successful limb-salvage procedure indicates that bioexpandable endoprosthesis may serve as a viable and effective reconstructive option in revision surgery for skeletally immature individuals.

• Keywords
• Bioexpandable prosthesis, Knee revision, Lengthening nail, Limb-salvage surgery, MUTARS® BioXpand, Periprosthetic infection, Precise nail,
• MeSH
• Femur * surgery   pathology   MeSH
• Prosthesis-Related Infections * surgery   etiology   MeSH
• Humans MeSH
• Adolescent MeSH
• Femoral Neoplasms * surgery   pathology   MeSH
• Bone Neoplasms * surgery   pathology   MeSH
• Osteosarcoma * surgery   pathology   MeSH
• Prognosis MeSH
• Reoperation MeSH
• Limb Salvage * methods   MeSH
• Plastic Surgery Procedures * methods   MeSH
• Check Tag
• Humans MeSH
• Adolescent MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Case Reports MeSH

BACKGROUND: Approximately, one-third of patients with tumors of proximal humerus will require an extra-articular resection to achieve oncologic margins. This procedure yields poor functional outcomes with a considerable rate of revisions. Unconstrained implants are prone to instability hindering also function of the elbow and hand, whereas constrained shoulder reconstructions suffer from early aseptic loosening of the glenoid component due to bone overload. The purpose of this study was to develop a constrained implant suitable for extra-articular resection with loss of function in deltoid and rotator cuff, which would provide both stability and passive motion, whilst also decreasing the risk of aseptic loosening of the glenoid component. METHODS: In cooperation with Czech Technical University in Prague, we devised an implant consisting of two constrained joints in series connected by a dumbbell piece. The biomechanical analysis showed a reduction of load transfer to the glenoid component with a torque of 8.6 Nm capable of generating an 865-N pulling force on bone screw to just 0.07 Nm, hence shielding the glenoid component from undesired forces and decreasing the risk of aseptic loosening. Three patients with extra-articular resection with a total loss of function of both rotator cuff and deltoid muscle received this type of reconstruction. The average follow-up was 16 months. RESULTS: The surgical technique is straightforward. The surgery took 175 min on average with average blood loss of 516 ml. There were no surgical- or implant-related complications. All three patients were pain-free and had a stable shoulder joint after the reconstruction. All had fully functional elbow, wrist, and hand joints. The average Musculoskeletal Tumor Society (MSTS) score was 21/30 (70%). All patients were pleased with the results. CONCLUSION: The presented innovative implant design has demonstrated to be a promising alternative for reconstruction in these challenging cases.

• Keywords
• Extra-articular resection, Sarcoma, Shoulder reconstruction, Tumor,
• MeSH
• Arthroplasty, Replacement * MeSH
• Humerus surgery   MeSH
• Humans MeSH
• Scapula MeSH
• Bone Neoplasms * surgery   MeSH
• Postoperative Complications etiology   MeSH
• Shoulder Joint * surgery   MeSH
• Shoulder MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH