Combining advanced technologies: the compress-repiphysis prosthesis for pediatric limb salvage

Outcomes of Expandable Prostheses for Primary Bone Malignancies in Skeletally Immature Patients: A Systematic Review and Pooled Data Analysis

BACKGROUND

Osteosarcoma and other primary bone malignancies are relatively common in skeletally immature patients. Current literature features case series with disparate complication rates, making it difficult for surgeons to educate patients on outcomes after limb salvage with expandable prostheses. This study aims to provide an update on complication rates, mortality, and functional outcomes in patients who undergo limb salvage with expandable prostheses for primary bone malignancies.

METHODS

A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. An exhaustive PubMed/Medline and Cochrane search of peer-reviewed published literature from 1997 to 2017 was performed, yielding a total of 1350 studies. After multiple rounds of review for inclusion and exclusion criteria, 28 retrospective studies were included. All were level IV evidence of case series and retrospective studies. Overall, this included 634 total patients and 292 patients with individual patient data. The primary outcomes studied were complication rates, mortality, and Musculoskeletal Tumor Society (MSTS) functional score. Secondary outcomes included complication rate subtypes, number of lengthening procedures, mean amount lengthened, and prevalence of limb length discrepancies.

RESULTS

A total of 292 patients with individual patient data averaged 10.1 years at the surgery and had a mean follow-up of 67 months. Two hundred sixteen patients (74%) had tumors of the distal femur. MSTS scores averaged 80.3 and overall mortality was 22%. Patients with distal femur tumors averaged 4.4 lengthening procedures and 43 mm lengthened. Leg length discrepancy (LLD) was 36% overall, which increased with longer periods of follow-up (P<0.001). Overall complication and revision rate was 43%, increasing to 59% in patients with 5 to 10 years of follow-up, and 89% in patients with >10 years of follow-up. Minimally invasive prostheses had lower rates of complications than noninvasive prostheses (P=0.024), specifically mechanical complications (P=0.028), mostly because of increased rates of lengthening and device failure in the noninvasive models (21% vs. 4%, P=0.0004).

CONCLUSIONS

Despite its limitations, which include entirely heterogenous and retrospective case series data, this systematic review provides clinicians with pooled summary data representing the largest summary of outcomes after reconstruction with expandable prostheses to date. This analysis can assist surgeons to better understand and educate their patients and their families on functional outcomes, mortality, and complication rates after limb-sparing reconstruction with expandable prostheses for primary bone malignancies.

LEVEL OF EVIDENCE

Level IV-retrospective case series with pooled data.

Surgical and Functional Outcomes After Limb-Preservation Surgery for Tumor in Pediatric Patients: A Systematic Review

BACKGROUND

Limb-salvage surgery and segmental reconstruction for the treatment of lower extremity osseous tumors in the pediatric population have been described in the literature, but there is little consensus regarding the optimal surgical treatment for this patient population.

METHODS

A systematic review of the literature was performed to identify studies focusing on limb-salvage procedures in pediatric patients who were managed with one of three reconstructions with use of a metallic endoprosthesis, allograft, or allograft-prosthesis composite. Data were segregated according to the excised and reconstructed anatomical location (proximal part of the femur, total femur, distal part of the femur, proximal part of the tibia) and were collated to assess modes of failure and functional outcomes of each reconstruction type for each anatomic location.

RESULTS

Sixty articles met the inclusion criteria; all were Level-IV evidence, primarily consisting of small, retrospective case series. Infection was a primary mode of failure across all reconstruction types and locations, whereas allograft reconstructions were susceptible to structural failure as well. The rate of failure in the pediatric population correlated well with previously published results for adults. The incidence of subsequent amputation was lower in the pediatric population (5.2%) than has been reported in adults (9.5%) (p = 0.013). Meaningful growth of expandable metallic endoprostheses was reported in the literature, with an overall rate of leg-length discrepancy of 13.4% being noted at the time of the latest follow-up. The Musculoskeletal Tumor Society (MSTS) questionnaire was the most consistently used outcome measure in the literature, with average scores ranging from 71.0% to 86.8%, depending on reconstruction type and anatomic location.

CONCLUSIONS

The current state of the literature detailing the surgical and functional outcomes of segmental reconstruction for the treatment of pediatric bone tumors is limited to Level-IV evidence and is complicated by under-segregation of the data by age and anatomical location of the reconstruction. Despite these limitations, pediatric limb-salvage surgery demonstrates satisfactory initial surgical and functional outcomes.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Reconstruction After Tumor Resection in the Growing Child

Limb preservation surgery has gained acceptance as a viable alternative to amputation for the treatment of extremity bone tumors in the growing child. There are several options for reconstructing the potential loss of a physis and the defect created by tumor excision. Metallic endoprosthesis, massive allograft, and allograft-prosthesis composites have been described in the skeletally immature population. With the development of expandable prostheses, even those far from skeletal maturity may be candidates for limb salvage. However, improvements in the literature are needed, including reporting surgical and functional outcomes in a rigorous manner, specific to age, anatomic location, and reconstruction.

Compress knee arthroplasty has 80% 10-year survivorship and novel forms of bone failure

BACKGROUND

Compliant, self-adjusting compression technology is a novel approach for durable prosthetic fixation of the knee. However, the long-term survival of these constructs is unknown.

QUESTIONS/PURPOSES

We therefore determined the survival of the Compress prosthesis (Biomet Inc, Warsaw, IN, USA) at 5 and 10 actuarial years and identified the failure modes for this form of prosthetic fixation.

METHODS

We retrospectively reviewed clinical and radiographic records for all 82 patients who underwent Compress knee arthroplasty from 1998 to 2008, as well as one patient who received the device elsewhere but was followed at our institution. Prosthesis survivorship and modes of failure were determined. Followup was for a minimum of 12 months or until implant removal (median, 43 months; range, 6-131 months); 28 patients were followed for more than 5 years.

RESULTS

We found a survivorship of 85% at 5 years and 80% at 10 years. Eight patients required prosthetic revision after interface failure due to aseptic loosening alone (n = 3) or aseptic loosening with periprosthetic fracture (n = 5). Additionally, five periprosthetic bone failures occurred that did not require revision: three patients had periprosthetic bone failure without fixation compromise and two exhibited irregular prosthetic osteointegration patterns with concomitant fracture due to mechanical insufficiency.

CONCLUSIONS

Compress prosthetic fixation after distal femoral tumor resection exhibits long-term survivorship. Implant failure was associated with patient nonadherence to the recommended weightbearing proscription or with bone necrosis and fracture. We conclude this is the most durable FDA-approved fixation method for distal femoral megaprostheses.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.