Stanmore noninvasive extendible endoprosthesis in the treatment of bone sarcoma in the preadolescent

Abstract

Aims The aim of this study is to assess outcomes of patients ≤12 years who undergo Stanmore noninvasive extendible endoprosthetic replacement of the distal femur (DF NIEPR). Patients and Methods A total of 101 children (mean age 9.6 years) were included. All complications which required further surgery were recorded. Clinical and functional outcomes were evaluated with Musculoskeletal Tumor Society (MSTS) scores at a mean follow‐up of 64 months (range 6‐174). Results Thirty‐one (30.7%) patients died at a mean of 33 months. Forty had prosthesis removed after a mean of 43 months (range, 7‐103). Attaining of the full lengthening potential before skeletal maturity was the most frequent reason for revision surgery, particularly in those with smaller lengthening potential (P = 0.039). Implant survival rate for other causes was 61.7% at 5 years and 45.0% at 10 years. At final follow‐up mean MSTS score was 26 (range, 13‐29). Twenty‐two (21.5%) patients had a final limb‐length discrepancy (LLD) > 2 cm. Conclusions DF NIEPR produces a good functional outcome, with the prevention of major LLD at skeletal maturity in the majority of the cases. We suggest patient selection criteria to account for the stage of the disease due to the high cost of the NIEPR, and high percentage requiring revision, and a 60% mortality rate in those patients presenting with distant disease burden.

Frequency and reason for reoperation following non-invasive expandable endoprostheses: A systematic review

“…2 ). [30] , [31] , [32] , [33] , [34] , [35] , [36] , [37] , [38] , [39] , [40] , [41] , [42] , [43] , [44] , [45] , [46] , [47] Included studies were published between 2003 and 2020. Altogether, these included a total of 495 patients, with a range of 6 to 101 patients included per study.…”

“…There were eight studies, encompassing 132 patients (26.7%), that analyzed outcomes of the Repiphysis® prosthesis (Microport Orthopedics, Arlington, Tennessee, USA) (originally the Phenix prosthesis). [30] , [31] , [40] , [41] , [42] , [43] , [44] Twelve studies, including 356 patients (71.9%), evaluated the Juvenile Tumour System (JTS) (Stanmore Implants, Elstree, UK) [32] , [33] , [34] , [35] , [36] , [37] , [38] , [39] , [41] , [46] , [47] and one study with seven patients (1.4%) evaluated the MUTARS® Xpand prosthesis (ImplantCast, Buxtehude, Germany). [45] The lengthening mechanisms of these implants vary, details of each are described in Table 1 .…”

Management of Primary Aggressive Tumors of the Knee

“…101 Despite improved outcomes with noninvasive extendible implants, revision rates remain high. 99,102,103 Osteoarticular allografts provide surgeons with another reconstruction option when joint preservation is not possible. Muscolo et al evaluated outcomes of 76 patients who underwent wide resection and reconstruction with a distal femur allograft.…”

“…101 Despite improved outcomes with noninvasive extendible implants, revision rates remain high. 99 102 103…”

Outcomes of Semiknee Replacement in Skeletally Immature Bone Sarcoma Patients

“…3,[13][14][15] Second, these extendible implants are much more expensive than their fixed-length counterparts. 3,4 Third, when the sarcoma originates in the proximal tibia, mega endoprosthesis with a hinge may damage the distal growth line of the femur. Fourth, as the extendible prostheses have a minimum body length (usually more than 160-170 mm) due to their sophisticated mechanical design, they might be not applicable for patients with a short resection length.…”