Megaprosthesis in Non-Oncologic Settings-A Systematic Review of the Literature

Comparative Outcomes and Failure Rates of Total Femur Replacement in Oncologic and Nononcologic Indications: A Systematic Review and Meta-analysis

BACKGROUND

Total femur replacement (TFR) has become increasingly significant as a salvage procedure for both oncologic reconstruction and complex nononcologic conditions such as revision arthroplasty. Despite its effectiveness in limb salvage, TFR is associated with high complication and failure rates, which vary depending on the underlying indication.

METHODS

This systematic review and meta-analysis adhered to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A comprehensive search of MEDLINE, EMBASE, Web of Science, and Cumulative Index to Nursing and Allied Health Literature databases was conducted, focusing on studies that reported outcomes of TFR in oncologic and nononcologic cases. Primary outcomes included failure mode and rates according to the Henderson classification, functional outcomes scores, and mobility status. Data were analyzed using random-effects models and generalized linear mixed models.

RESULTS

A total of 35 studies involving 1,002 patients were included. The majority of TFRs were performed for oncologic reasons (63.7%). The mean Musculoskeletal Tumor Society (MSTS) score was 66%, with a limb salvage rate of 89%. The meta-analysis revealed a combined failure rate of 34%. For type 4 failures (infection), nononcologic patients exhibited a significantly higher rate at 18% (95% confidence interval [CI], 12%-26%, I2 = 46%, p < 0.01) compared with 8% in oncologic patients (95% CI, 6%-12%, I2 = 0%). Regarding combined types 1 to 4 failures, oncologic patients had a rate of 20% (95% CI, 25%-52%, I2 = 60%), whereas nononcologic patients faced a higher rate of 37% (95% CI, 12%-26%, I2 = 63%) (p < 0.05), indicating a significant difference. There were no significant differences in the MSTS score. In addition, there were no notable differences when comparing failure modes 1, 2, and 3 independently. Mobility analysis showed that approximately 70% of patients required walking aids after surgery.

CONCLUSION

TFR offers a valuable limb salvage option in both oncologic and nononcologic scenarios, despite its high failure rates. Although functional outcomes were similar between groups, the higher failure rate in nononcologic cases and the poor overall quality of evidence warrant further comprehensive assessments into predictors of outcomes to optimize results.

LEVEL OF EVIDENCE

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

Characteristics and Epidemiology of Megaprostheses Infections: A Systematic Review

BACKGROUND

Megaprostheses were first employed in oncological orthopedic surgery, but more recently, additional applications have arisen. These implants are not without any risks and device failure is quite frequent. The most feared complication is undoubtedly the implants' infection; however, the exact incidence is still unknown. This systematic review aims to estimate in the current literature the overall incidence of megaprosthesis infections and to investigate possible risk/protective factors.

METHODS

We conducted a systematic search for studies published from July 1971 to December 2023 using specific keywords. To be included, studies needed to report either the megaprosthesis anatomical site, and/or whether the megaprosthesis was coated, and/or the surgical indication as oncological or non-oncological reasons.

RESULTS

The initial literature search resulted in 1281 studies. We evaluated 10,456 patients and the overall infection rate was 12%. In cancer patients, the infection rate was 22%, while in non-oncological patients, this was 16% (trauma 12%, mechanical failure 17%, prosthetic joint infections 26%). The overall infection rates comparing coated and uncoated implants were 10% and 12.5%, respectively.

CONCLUSIONS

The number of megaprosthesis implants is increasing considerably. In traumatological patients, the infection rate is lower compared to all the other subgroups, while the infection rate remains higher in the cancer patient group. As these devices become more common, focused studies exploring epidemiological data, clinical outcomes, and long-term complications are needed to address the uncertainties in prevention and management.

Periprosthetic giant cell tumour of the tibia: en bloc resection and megaprosthesis revision

We present a case detailing the diagnosis and management of a periprosthetic giant cell tumour in a female patient in her 70s, who had undergone total knee arthroplasty (TKA) for primary osteoarthritis in her right knee 7 years prior. The patient reported 4 months of painful weight-bearing. Various imaging modalities, including plain radiographs, CT scans and MRI, revealed a sizeable lytic lesion beneath the TKA prosthesis, along with loosening of the tibial component.Blood tests and analyses of synovial fluid ruled out periprosthetic joint infection, and a biopsy confirmed the diagnosis of a giant cell tumour of the bone. Treatment entailed en bloc resection of the tumour and revision of the TKA using a hinged, oncological-type megaprosthesis. Surgical procedures involved careful resection of the proximal tibia, preservation of vasculature and the creation of a medial gastrocnemius muscle flap. Following surgery, the patient underwent supervised rehabilitation with a functional brace.

Patient-Reported Outcomes and Range of Motion Following Knee Arthroplasty Using a Megaprosthesis in Non-Oncological Patients: A Systematic Review

BACKGROUND

This review aimed to determine outcomes following megaprostheses in non-oncological indications for knee arthroplasty, including range of motion (ROM) and patient-reported outcome measures of function, pain, and quality of life (QoL).

METHODS

A search of MEDLINE, Embase, and Cochrane via Ovid and PubMed between January 2003 and June 2023 was conducted. Studies reporting function, pain, ROM, and/or QoL in non-oncological patients who have received knee megaprostheses were included. Studies with sample sizes (n ≤ 5) were excluded. The risk of bias was assessed using the Downs and Black Quality Checklist for Health Care Intervention Studies. Central tendency measures (mean or median) were reported at each time point, and dispersion measures were extracted and reported whenever data were available.

RESULTS

A total of 30 studies (involving 1,294 megaprostheses) were included. Of which, 14 of 30 studies reviewed patients who had mixed indications; 14 of 30 looked at fracture only; 1 of 30 focused on distal femur nonunion; and 1 of 30 focused on patients who had periprosthetic infections. The average patient follow-up time was 40.1 months (range, 1.0 to 93.5). Most studies presented a high risk of bias (27 of 30), while a few (3 of 30) presented a low risk of bias. Improvements from preoperative baseline were observed in 85.7% of studies that reported baseline and follow-up data for function (12 of 14), 100.0% pain (4 of 4), 90.9% ROM (10 of 11), and 66.6% QoL (2 of 3).

CONCLUSIONS

Favorable function, pain, ROM, and QoL outcomes following knee megaprostheses in non-oncological patients were observed. Heterogeneity in outcome measures and follow-up periods prevented the pooling of data. Future comparative studies are warranted to enhance the body of evidence relating to knee megaprostheses in non-oncological patients.

Reverse Shoulder Megaprosthesis for Massive Proximal Humeral Bone Loss in Fracture Outcome Settings: A Report of Two Cases and Literature Review

In trauma settings, including the management of outcomes, there is no consensus on the most appropriate reconstructive method in the presence of severe bone loss of the proximal humerus. The objective of this report is to evaluate the short-term functional outcomes of two patients in whom reverse shoulder megaprosthesis was used to treat the failure of trauma surgery with severe bone loss. The secondary objective was to compare the results obtained with the literature regarding the use of megaprosthesis in shoulder trauma surgery. The patients showed a satisfying functional recovery and increased quality of life. At the 12-month follow-up, no complications occurred. Regarding the risk of complications, especially the risks of mobilization of the megaprosthesis, the CT-based intraoperative navigation system optimizes the configuration of the screw for the initial fixation of the glenoid component. Shoulder megaprosthesis appears to be a viable option not only in oncologic surgery but also in cases of failed trauma surgery. The functional results, considering functional score and range of motion, are encouraging and allow patients to improve their quality of life.

Reduction of the Femoral Head First, and Assembly of the MUTARS® Device in Case of Impossible Reduction during Total Hip Arthroplasty

Dislocation after a total hip arthroplasty occurs in approximately 1% of patients; however, the frequency is much higher after revision surgery. To prevent dislocation, use of a larger femoral head is recommended, and a dual mobility femoral head has been introduced. However, reducing the dual mobility femoral head to the acetabular component is difficult in cases involving contracture in the soft tissue around the joint. A 72-year-old male patient who developed a periprosthetic joint infection underwent two-stage revision surgery using MUTARS®. Two months after the revision, the hip joint became dislocated and manual reduction was attempted; however, dislocation occurred again. During another revision using a dual mobility bearing, the soft tissue around the hip joint was too tight to reduce. The problem was overcome by first repositioning the dual mobility head into the acetabular socket, followed by assembly of the diaphyseal portion of the implant.

Silver-Coated Distal Femur Megaprosthesis in Chronic Infections with Severe Bone Loss: A Multicentre Case Series

Periprosthetic joint infections (PJI) and fracture-related infections (FRI) of the distal femur (DF) may result in massive bone defects. Treatment options include articulated silver-coated (SC) megaprosthesis (MP) in the context of a two-stage protocol. However, there is limited evidence in the literature on this topic. A retrospective review of the prospectively maintained databases of three Institutions was performed. Forty-five patients were included. The mean follow-up time was 43 ± 17.1 months. Eight (17.8%) patients had a recurrent infection. The estimated recurrence-free survival rate was 91.1% (93.5% PJI vs. 85.7% FRI) 2 years following MP implantation, and 75.7% (83.2% PJI vs. 64.3% FRI; p = 0.253) after 5 years. No statistically relevant difference was found according to the initial diagnosis (PJI vs. FRI). Among possible risk factors, only resection length was found to significantly worsen the outcomes in terms of infection control (p = 0.031). A total of eight complications not related to infection were found after reimplantation, but only five of them required further surgery. Above-the-knee amputation was performed in two cases (4.4%), both for reinfection. Articulated DF SC MP in a two-stage protocol is a safe and effective treatment for chronic knee infection with severe bone loss.