Proximal Femoral Allograft-Prosthetic Composites: Do They Really Restore Bone? A Retrospective Review of Revision Allograft-Prosthetic Composites

Using hardystonite as a biomaterial in biomedical and bone tissue engineering applications

Widespread adoption for substitutes of artificial bone grafts based on proper bioceramics has been generated in recent years. Among them, calcium-silicate-based bioceramics, which possess osteoconductive properties and can directly attach to biological organs, have attracted substantial attention for broad ranges of applications in bone tissue engineering. Approaches exist for a novel strategy to promote the drawbacks of bioceramics such as the incorporation of Zn2+, Mg2+, and Zr4+ ions into calcium-silicate networks, and the improvement of their physical, mechanical, and biological properties. Recently, hardystonite (Ca2ZnSi2O7) bioceramics, as one of the most proper calcium-silicate-based bioceramics, has presented excellent biocompatibility, bioactivity, and interaction. Due to its physical, mechanical, and biological behaviors and ability to be shaped utilizing a variety of fabrication techniques, hardystonite possesses the potential to be applied in biomedical and tissue engineering, mainly bone tissue engineering. A notable potential exists for the newly developed bioceramics to help therapies supply clinical outputs. The promising review paper has been presented by considering major aims to summarize and discuss the most applicable studies carried out for its physical, mechanical, and biological behaviors.

Biomechanical analysis of different techniques for residual bone defect from tibial plateau bone cyst in total knee arthroplasty

Background

In patients with tibial plateau bone cysts undergoing total knee arthroplasty (TKA), bone defects commonly occur following tibial plateau resection. Current strategies for addressing these defects include bone grafting, bone cement filling, and the cement-screw technique. However, there remains no consensus on the optimal approach to achieve the best surgical outcomes. This study aims to evaluate the most effective repair method for residual bone defects following tibial plateau bone cyst repair during TKA from a biomechanical perspective.

Methods

The treatment options for tibial plateau bone defects were classified into four categories: no treatment, cancellous bone filling, bone cement filling, and the cement-screw technique. Finite-element analysis (FEA) was employed to evaluate stress distribution and displacement across the models for each treatment group. In addition, static compression mechanical tests were used to assess the displacement of the models within each group.

Results

FEA results indicate that when employing the cement-screw technique to repair tibial plateau bone defects, the maximum stress on the prosthesis and the cement below the prosthesis is minimized, while the maximum stress on the cancellous bone is maximized. And the displacement of each component is minimized. Biomechanical tests results further demonstrate that the displacement of the model is minimized when utilizing the cement-screw technique for tibial plateau bone defects.

Conclusion

Using cement-screw technique in treating residual tibial bone defects due to bone cysts in TKA offers optimal biomechanical advantages.

Allograft-prosthesis composite after proximal femur bone tumor resection in pediatric age: Is it effective in preserving bone stock?

Purpose

The purpose of the study was to answer the following questions. What was functional results of pediatric patients receiving a short stem allograft-prosthesis composite of the proximal femur? What was complication rate and revision-free implant survival? Was it possible to preserve the bone stock of the proximal femur in pediatric patients?

Methods

We reviewed 10 pediatric patients treated with proximal femur resection for a primary bone tumor and reconstruction with short stem allograft-prosthesis composite, with at least 24 months follow-up. The median age was 9 years (4-13) at surgery. The mean resection length was 15 cm (6-29). In six cases, fixation was performed with a short plate positioned under the great trochanter while in four cases a long plate extended over the great trochanter was employed.

Results

Nine complications that required surgical revision were assessed in six patients (one wound dehiscence, two nonunions, two fractures, one acetabular wear, three hypometria), while allograft-prosthesis composite removal was required in three patients. The revision-free survival was 57% (95% confidence interval 33%-100%) at 5 and 10 years. The graft removal-free survival was 75% (95% confidence interval 50%-100%) at 5 and 10 years. The mean Musculo-Skeletal Tumor Society Score was 28 (20-30).

Conclusions

Allograft-prosthesis composites with short stem and compression plate represents an effective reconstructive option after proximal femur resection for primary bone tumors in growing patients, preserving bone stock. The use of a compression plate extended over the greater trochanter seemed to reduce failure rate.

Proximal femoral replacement for non-neoplastic conditions: a systematic review on current outcomes

Proximal femoral replacement (PFR) is a well-established treatment for neoplasia of the proximal femur. The use of this surgical technique for non-neoplastic conditions has increased over the years. We carried out a systematic review of the literature to study the indications, complications, and functional results when PFR is used for non-neoplastic conditions. Twenty-seven studies were included in the review with a total of 828 PFRs with a mean follow-up of 50 months (range 1-225 months). The main indications were infection (28%), periprosthetic fracture (27%), aseptic loosening (22%), and fracture (16%). The rate of reoperation was 20.3% overall. The overall revision rate was 15.4%. The main complications were dislocation (10.2%) and infection (7.3%). After 2010, the rates of reoperation (25.5% versus 18.2%), loosening (9.4% versus 3.2%), and dislocation (15.7% versus 7.9%) were lower than before 2010. The 30-day mortality ranged from 0% to 9%. The hip function scores improved post-surgery. In conclusion, the use of PFR in non-neoplastic conditions remains a marginal tool, associated with low direct mortality and high complication rates, but we expect its use to increase in the near future.

Survival Analysis of Allografting and Antiprotrusio Cage in Treating Massive Acetabular Bone Defects

BACKGROUND

Massive acetabular bone defects reconstructed with allografting and antiprotrusio cage in revision hip arthroplasty is less reported in the literature. We here report a series of 84 antiprotrusio cages and analyze the risk factors associated with failure.

METHODS

All instances of use of an antiprotrusio cage for massive acetabular defect (Paprosky type IIc, III, and pelvic discontinuity) between 2002 and 2017 in the authors' institute were reviewed after institutional review board's approval. Survival analyses based on clinical data, bone defect (Paprosky system), type of allograft, size of cage, fixation quality, and position of cage were performed. Failure was defined as cage loosening or breakage, poor hip function, or cage revision for any reason.

RESULTS

A total of 84 cages in 77 patients (mean age, 62.9 years), with a mean follow-up period of 6.2 years, had a survival rate of 82.1%. Failure was noted in 15 hips, including mechanical failure in 8 hips, recurrent dislocation in 1 hip, poor hip function in 1 hip, and periprosthetic joint infection in 5 hips. Pelvic discontinuity, reconstruction with morselized allograft alone, and fewer than 4 fixation points to the host bone were associated with higher failure rates (hazard ratios, 4.02, 3.42, and 9.9, respectively).

CONCLUSION

We found that an antiprotrusio cage combined with strut allografts, fixed securely to the host bone (>4 fixation points), are beneficial for the management of massive acetabular bone defects. However, pelvic discontinuity remains a challenge that warrants the further study of technical or prosthetic innovations, such as triflange implants, cup cage, and 3D-printed implants.

Long-term results of uncemented allograft prosthesis composite reconstruction for the tumor in proximal femur: a minimum follow-up of sixty-five months

BACKGROUND

Uncemented allograft prosthesis composite (APC) has been applied for tumorous bone defect reconstruction in the proximal femur. However, the long-term results are rarely reported. This study aimed to evaluate long-term outcomes of uncemented APC.

METHODS

Eighteen patients who received uncemented APC reconstruction in the proximal femur after tumor resections were retrospectively reviewed.

RESULTS

The average resection length was 110 mm (80-154) and the average follow-up was 106.7 months (65-141). Bone union achieved in all patients with an average duration of 7.6 months (5-10). The average HHS, MSTS score and gluteus medius strength at one-year follow-up were 88.0 (80-94), 25.2 (22-28) and 4 (3-5), respectively. While at the last follow-up, the HHS, MSTS score and gluteus medius strength were 83.0 (48-100), 24.0 (10-30) and 4 (2-5), respectively. Five intraoperative fractures were fixed with cerclage wires. Two postoperative periprosthetic and prosthetic fractures received a revision. Three local recurrent patients received a secondary surgery. One of these three lung metastatic patients underwent lung metastatic tumor resection. Another two patients were diagnosed with both bone and lung metastases, only one of them underwent amputation. Two greater trochanteric fractures received no treatment. There were10 severe, 3 moderate and 5 mild allograft resorptions without treatment.

CONCLUSION

Uncemented APC is a reliable reconstruction for neoplastic bone defect of the proximal femur, especially for the young patient who expected long-life expectancy and good function. Though allograft resorption and trochanteric fracture are the common complications, they seem no effect on the function.

A comparative study of autogenous, allograft and artificial bone substitutes on bone regeneration and immunotoxicity in rat femur defect model

Repair and reconstruction of large bone defect were often difficult, and bone substitute materials, including autogenous bone, allogenic bone and artificial bone, were common treatment strategies. The key to elucidate the clinical effect of these bone repair materials was to study their osteogenic capacity and immunotoxicological compatibility. In this paper, the mechanical properties, micro-CT imaging analysis, digital image analysis and histological slice analysis of the three bone grafts were investigated and compared after different time points of implantation in rat femur defect model. Autogenous bone and biphasic calcium phosphate particular artificial bone containing 61.4% HA and 38.6% β-tricalcium phosphate with 61.64% porosity and 0.8617 ± 0.0068 g/cm³ density (d ≤ 2 mm) had similar and strong bone repair ability, but autogenous bone implant materials caused greater secondary damage to experimental animals; allogenic bone exhibited poor bone defect repair ability. At the early stage of implantation, the immunological indexes such as Immunoglobulin G, Immunoglobulin M concentration and CD4 cells' population of allogenic bone significantly increased in compared with those of autologous bone and artificial bone. Although the repair process of artificial bone was relatively inefficient than autologous bone graft, the low immunotoxicological indexes and acceptable therapeutic effects endowed it as an excellent alternative material to solve the problems with insufficient source and secondary trauma of autogenous bone.

A retrospective review of revision proximal humeral allograft-prosthetic composite procedures: an analysis of proximal humeral bone stock restoration

BACKGROUND

Allograft-prosthetic composite (APC) reconstruction of the proximal humerus is a technique for reconstruction of large bone deficits, provides improvement in pain and function, and is thought to restore bone if revision surgery is needed. The purpose of this study was to evaluate the ability of proximal humeral APCs to restore usable bone at the time of revision surgery.

METHODS

Two institutional electronic medical records were reviewed to evaluate proximal humeral APC procedures performed between 1970 and 2018. We identified 115 cases, of which 14 underwent revision for aseptic causes. The indications for revision included nonunion (n = 7), glenohumeral instability (n = 5), and allograft fracture (n = 2). Three categories were used to classify the amount of usable allograft retained at revision surgery: type A, complete allograft retention; type B, partial retention; and type C, no retention.

RESULTS

A total of 14 patients (6 male and 8 female patients) underwent revision of the APC reconstruction at a mean of 22.8 months. At revision, allograft retention was classified as type A in 6 shoulders, type B in 3, and type C in 5. Type A cases were associated with nonunion with a well-fixed stem, type B cases were associated with instability and were converted from a hemiarthroplasty to a reverse total shoulder arthroplasty, and type C cases were associated with an allograft fracture or nonunion with a loose humeral component.

CONCLUSION

A substantial number of revisions of proximal humeral APC reconstructions maintain a portion of the allograft bone (64.3%). This study supports the ongoing use of the APC reconstruction technique for large bone deficits.

Allogenic bone graft for femoral defect augmentation in hip revision arthroplasty: A case series

Cortical bone loss in revision hip arthroplasty requires an adequate stabilization to achieve a durable implant fixation. This case series shall illustrate possible indications for the use of allogenic grafts in revision hip arthroplasty. Twelve patients with femoral bone loss were treated with allografts. In addition to established clinical scores, the radiological follow-ups were analyzed for hints of implants loosening and the osteointegration of the allografts. After a mean follow-up of 3.0 years the mHHS was 61.3 points and the UCLA 3.8. One patient showed a non-progressive radiolucency around the hip implant. The osteointegration of all allogenic grafts happened on time. Up to the last follow-up no revision surgery of the hip implants and the associated femoral bone graft was observed. Allogenic bone grafts present a method for biological stabilization in situations of large femoral cortical bone defects in revision hip arthroplasty.

Using personalized 3D printed Titanium sleeve-prosthetic composite for reconstruction of severe segmental bone loss of proximal femur in revision total hip arthroplasty: A case report

RATIONALE

Allograft-prosthetic composites (APCs) and proximal femoral replacement have been applied for reconstruction of severe segmental femoral bone loss in revision total hip arthroplasty. The outcomes are encouraging but the complication rate is relatively high. Considering the high complication rates and mixed results of APCs and megaprosthesis, we presented a case using personalized 3D printed Titanium sleeve-prosthetic composite for reconstruction of segmental bone defect.

PATIENT CONCERNS

A 73-year-old woman presented to the emergency department on account of acute severe pain of the left hip without history of trauma. She had undergone a cemented total hip arthroplasty for osteonecrosis of femoral head at the left side in 2000. In 2013 she underwent a cemented revision total hip arthroplasty as a result of aseptic loosening of hip prosthesis. She denied obvious discomfort prior to this episode since the revision surgery in 2013.

DIAGNOSIS

According to the clinical history, imaging and physical examination, we confirmed the diagnosis of severe segmental bone loss of proximal femur and fracture of prosthetic stem. The femoral bone defect was evaluated using the Paprosky classification system and rated as Type 3B, and the acetabular bone defect was rated as Type 2C.

INTERVENTIONS

In this study, we present the first case of severe segmental bone loss of proximal femur in revision total hip arthroplasty that was successfully treated using personalized 3D printed Titanium sleeve-prosthetic composite OUTCOMES:: At the 2-year follow-up, the patient was symptom free with a Harris Hip Score of 91. Radiographs showed excellent osteointegration between the interface of sleeve-prosthetic composite and the host bone, with no signs of implant loosening or subsidence.

LESSONS

Despite the absence of long term results of 3D printed Titanium sleeve-prosthetic composite reconstruction, the good clinical and radiological outcome at 2 years follow up implied its potential role for reconstruction of segmental femoral bone defect in revision THA.