Limb salvage surgery (LSS) has become the preferred treatment for primary malignant bone tumors of the extremities, replacing amputation in nearly 90–95% of eligible cases while achieving comparable oncologic control ^[1,2]. This approach emphasizes wide tumor excision, preservation of limb function, and improved quality of life for patients. The majority of these tumors occur in load-bearing bones, with the distal femur accounting for approximately 37% of cases, followed by the proximal tibia (19%), proximal humerus, and proximal femur ^[3]. The principal tumor types treated with limb salvage procedures include osteosarcoma, Ewing’s sarcoma, chondrosarcoma, and giant cell tumors. Advances in neoadjuvant chemotherapy, cross-sectional imaging, and reconstructive techniques have significantly improved the safety and functional success of limb-sparing surgery, leading to 5-year survival rates exceeding 60–70% in non-metastatic osteosarcoma patients ^[4].

Restoring limb biomechanics and function following tumor resection remains a key challenge. Various reconstructive strategies have been developed, including biological options such as allografts, autografts, arthrodesis, and rotationplasty. However, modular endoprosthetic reconstruction (megaprosthesis) has gained the widest acceptance due to its intraoperative adaptability, immediate structural stability, and facilitation of early mobilization ^[5,6]. These implants are particularly advantageous for metaphyseal and epiphyseal lesions where joint preservation is not feasible.

Functional outcomes following megaprosthetic reconstruction are generally favourable, with 70–85% of patients achieving good to excellent results. Functional recovery has been most commonly assessed using the musculoskeletal tumor society (MSTS) score and, in several recent studies, the Toronto extremity salvage score (TESS). Other complementary indicators – such as range of motion (ROM), gait analysis (e.g., 6 min walk test or gait deviation index [GDI]), pain reduction, Karnofsky Performance Status (KPS), and return to work capability have also been reported, providing a broader understanding of post-operative functional restoration. Despite these encouraging outcomes, residual limitations, including restricted joint motion, gait asymmetry, persistent pain, and reduced activity levels, may still impact overall quality of life.

Complications remain a major concern. Deep infections occur in approximately 10–20% of cases, while aseptic loosening, mechanical failures, and periprosthetic fractures continue to threaten long-term prosthesis survival and may necessitate revision surgery or, in severe instances, secondary amputation ^[7]. These complications are influenced by tumor site, prosthesis design, and soft-tissue reconstruction Quality.

Given the complexity of reconstruction and variability in outcomes across anatomical sites, understanding functional recovery patterns, complication profiles, and prosthesis longevity is crucial for optimizing patient outcomes. Therefore, this review aims to synthesize current evidence on the functional and non-functional outcomes of megaprosthetic reconstruction following LSS, with particular attention to site-specific challenges and complication rates.

This scoping review was conducted according to the Arksey and O’Malley scoping framework ^[8] and reported with reference to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement to enhance transparency in study identification and selection. The study selection process is illustrated in the PRISMA flow diagram (Fig. 1) ^[9]. A comprehensive search was performed across PubMed, Scopus, Google Scholar, and EBSCO databases for studies published between January 2014 and May 2025, guided by the population, intervention, comparison, outcome framework (Table 1). A structured combination of MeSH terms and keywords related to bone tumors, LSS, endoprosthetic or megaprosthetic reconstruction, and functional or complication outcomes was applied, with detailed search logic outlined in (Table 2). The initial search yielded 324 records, and after duplicate removal and screening, 47 full-text articles were assessed, of which 19 met the inclusion criteria. Eligible studies were English language publications (2014–2025), available in full text, focusing on LSS using modular or custom megaprosthetic reconstruction for primary or recurrent bone tumours, and reporting at least one functional outcome (e.g., MSTS, TESS, ROM, pain, or quality of life) and at least one complication outcome (infection, mechanical failure, aseptic loosening, or revision surgery). Excluded were studies with fewer than five patients, conference abstracts, reviews, non-English papers, non-extractable data, or follow-up shorter than 6 months.

Methodological quality and risk of bias of the included non-randomized observational studies were assessed using the Newcastle Ottawa scale (NOS) for cohort studies. The critical appraisal skills programme checklist ^[10] was used as a supportive framework to aid critical appraisal and interpretation of study findings. The assessment evaluated three key domains: Selection of study cohorts, comparability of cohorts based on study design or analysis, and adequacy of outcome assessment and follow-up. Risk of bias judgments for individual NOS domains were summarized and visualised using the risk of bias tool, employing a generic risk of bias framework. After the bias assessment, data were extracted using a structured template (Table 3) documenting study design, sample size, demographics, tumor type and site, prosthesis details, surgical margins, follow-up duration, functional outcomes, and complication profiles. Due to heterogeneity in study design, prosthesis models, and outcome reporting, results were synthesised through a qualitative narrative approach rather than meta-analysis. The review further analysed patterns in functional recovery, complication rates, prosthesis survivorship, and regional practice trends, while identifying gaps in evidence concerning long-term implant performance, rehabilitation protocols, and design innovation to inform future research directions.

Study scope and patient demographics

This review included 19 studies published between 2014 and 2025, encompassing a total of 610 patients who underwent LSS with megaprosthetic reconstruction for primary or recurrent bone tumors. Patient ages ranged from 13 to 47 years, with several studies focusing on pediatric and adolescent groups receiving expandable prostheses. Geographically, India contributed eight studies, followed by China (three), Egypt (two), France (two), and one each from Spain, Bulgaria, Denmark, and Pakistan. Study designs comprised prospective cohorts, retrospective series, cross-sectional, and case–control studies, with follow-up durations ranging from 6 months to more than 8 years.

Risk of bias assessment

Overall, the included studies demonstrated predominantly moderate risk of bias across NOS domains. Most studies showed low risk in selection representativeness and outcome assessment, reflecting well-defined cohorts and the use validated functional outcome measures. However, comparability between cohorts was frequently limited due to a retrospective study design and a lack of adjustment for confounding variables. In several studies, the absence of a clearly defined non-exposed comparator group contributed to higher risk ratings in selection-related domains. Follow-up duration and adequacy were generally moderate, with variability in reporting of loss to follow-up. A summary of the domain-specific risk of bias assessment is presented in Fig. 2.

Surgical techniques and prosthesis types

Across the included literature, both modular and custom megaprostheses were used, with common systems including MUTARS, RESTOR, GMRS, and silver-coated or cemented variants. Modular implants predominated in India, China, and Egypt because of their cost-effectiveness, intraoperative adaptability, and ease of revision, whereas custom implants were favoured in European centers for precise anatomical reconstruction in complex resections. Silver-coated prostheses demonstrated lower infection rates (7.9% vs. 16.7%) and improved revision-free survival ^[11,12], while cemented fixation allowed earlier weight bearing and faster mobilization. Modular systems also facilitated simpler revision procedures in cases of loosening or mechanical failure ^[13,14,15].

Functional outcomes

Functional recovery was favourable, influenced by rehabilitation intensity, early mobilisation, prosthesis design, and anatomical site ^[16]. The MSTS score was the predominant outcome tool, while three studies also used the TESS. Additional parameters such as ROM, gait and biomechanical analysis (6-min Walk Test, Timed Up and Go, GDI), pain scores (Visual Analog Scale), KPS, and return to work or activities of daily living measures were variably reported.

Across all cohorts, MSTS/TESS scores ranged from 66.6% to 89.7%, indicating good to excellent limb function. The distal femur remained the most frequently reconstructed site and consistently yielded mean MSTS scores exceeding 80%, attributed to better biomechanics, soft-tissue coverage, and structured physiotherapy ^[17]. Proximal femur and proximal humerus reconstructions showed lower functional scores (66–73%), reflecting abductor weakness and limited joint mobility ^[18,19] (Fig. 3). ROM data were reported in eight studies, with mean knee flexion ranging between 80° and 110° post-rehabilitation, extension lag of 5–20° in proximal tibial cases, and shoulder abduction between 70–90° after proximal humeral reconstruction. Biomechanical assessments were presented in three European studies, which demonstrated near-normal gait kinematics with GDI values of 86–89 compared to 94 in healthy controls and mildly prolonged 6MWT and TUG times. In Pu et al. (2023), KPS improved significantly from 50 preoperatively to 70–90 postoperatively, indicating restored independence. Early physiotherapy and weight bearing within 6–8 weeks were consistently associated with superior function, faster gait recovery, and higher satisfaction ^[20].

Non-functional outcomes

Non-functional results, including oncologic control, prosthesis longevity, and psychosocial recovery, were encouraging. Local recurrence ranged from 6.45% to 9.3% ^[13,14], while metastatic spread occurred in 7–18.2% of patients ^[17,18]. Five-year limb retention rates exceeded 88% in nearly all cohorts, with several reporting stable 10-year survivorship ^[11,12]. For example, Ebeid et al. (2023) documented 82.1% wide surgical margins and only 7% secondary amputations due to recurrence or severe complications. Distal femur reconstructions achieved the best local control ^[14], whereas proximal humerus and pelvic reconstructions carried slightly higher recurrence risks ^[19]. Psychosocial and return to work outcomes were addressed in five studies. Fernandes et al. (2023) reported 70% return to employment with a mild reduction in work capacity compared to controls, while Satish et al. (2019) and Jover-Jorge et al. (2024) observed better emotional well-being, self-image, and social reintegration among limb salvage patients compared to amputees. Ebeid et al. (2023) and Ivanov et al. (2023) similarly reported high patient satisfaction and improved quality of life following structured rehabilitation ^[21].

Complications and survivorship

Complications influenced long-term outcomes, with deep infection being the most common (5.1–23.6%), particularly in Egyptian and Chinese cohorts, despite the use of silver coatings ^[11,13]. Aseptic loosening occurred in 6.25–14.5% of patients, primarily in Indian and Pakistani studies ^[14,15]. Mechanical failures – including prosthetic breakage, hinge malfunction, periprosthetic fracture, and expansion mechanism defects – were observed in 6.5–12.5% of cases, with higher incidence among skeletally immature patients undergoing expandable reconstructions due to repeated lengthening and growth stresses ^[22]. A bar chart demonstrating pooled mean incidence of major complications following megaprosthesis reconstruction, including infection, aseptic loosening, mechanical failure, local recurrence, and metastasis (Fig. 4). Despite these complications, implant survival remained robust, with 5-year limb retention consistently above 88% and multiple studies reporting durable functionality beyond 10 years ^[11,12].

Recovery after LSS extends far beyond restoring bone and muscle – it represents the restoration of independence, identity, and quality of life. Across the 19 core studies (n > 600), patients frequently described regaining the ability to walk independently, return to work, and reclaim personal autonomy as defining milestones of recovery. Collectively, these outcomes reaffirm that megaprosthetic reconstruction is not merely a technical triumph but a means of restoring function and dignity. Long-term survivorship data have been equally encouraging, with several reports demonstrating that proximal femoral endoprostheses achieve more than 85% survival at 10 years, underscoring their durability in experienced oncologic centers ^[23].

Interpretation of these results, however, must be cautious given the predominance of retrospective designs, limited randomization, and heterogeneity in implant types and follow-up durations across studies. Functional outcomes, most commonly assessed through the MSTS and TESS, consistently demonstrated good to excellent recovery, with mean values ranging between 66% and 89%. These scores reflect an overall improvement in limb function, pain reduction, emotional acceptance, and independence in daily activities – highlighting that megaprosthetic reconstruction achieves both mechanical and functional recovery. Parallel gains in joint mobility and gait performance confirmed smoother biomechanical adaptation and efficient ambulation following structured rehabilitation. Improvements observed in performance indices such as the GDI and Timed Up and Go tests suggest that patients achieved near-normal walking symmetry and endurance. Similarly, higher KPS and increased return to work rates underscored the restoration of physical capacity, self-care ability, and social reintegration. Together, these multidimensional improvements confirm that LSS restores not only the integrity of the limb but also the patient’s overall quality of life and independence.

Hardes et al. demonstrated that silver-coated prostheses reduce infection risk by nearly half, offering a valuable preventive strategy against one of the most devastating complications ^[24]. Nevertheless, mechanical failures – including hinge fractures, component fatigue, aseptic loosening, and expansion mechanism defects remain significant challenges, particularly among children and adolescents treated with expandable implants, where repeated lengthening increases mechanical stress and revision rates ^[25]. Early initiation of rehabilitation and progressive weight bearing after reconstruction have been repeatedly shown to enhance functional recovery, accelerate ambulation independence, and improve MSTS and TESS scores among limb salvage patients ^[26].

Beyond surgical technique, social and economic contexts profoundly influence long-term outcomes. Gronchi et al. (2021) emphasised that optimal sarcoma management should be centralised in multidisciplinary reference centers where surgeons, oncologists, physiotherapists, and psychologists collaborate to optimise oncologic control, functional recovery, and emotional adaptation ^[27]. Duijts et al. (2014) further noted that even after successful physical recovery, many cancer survivors face ongoing psychosocial barriers, including anxiety and challenges returning to work or social activities ^[28]. In resource-limited settings, modular systems are often preferred due to their affordability and versatility; however, restricted access to structured rehabilitation and socioeconomic constraints can impede functional recovery and quality of life outcomes. Future studies should incorporate socioeconomic indicators such as income, education, and rehabilitation access to present a more comprehensive picture of recovery trajectories.

From an oncologic standpoint, achieving wide surgical margins remains the cornerstone of durable limb preservation. Ebeid et al. reported that 82% of patients with histologically clear margins retained their limbs at 5 years, reaffirming the delicate balance between oncologic safety and functional preservation ^[29]. By systematically searching four major databases, we were able to map both outcomes and complications rates over 600 patients worldwide. This provides a broad and realistic picture of how megaprosthetic reconstruction perform across different anatomical sites and healthcare settings. Because the included studies varied significantly in their study design, prosthetic models and follow-up durations, a statistical meta analysis was unable to be conducted. Furthermore, our review is limited by available literature as most of the underlying studies are retrospective and single-center series. Progress in this field now depends on methodological refinement. Moving forward, the establishment of multi-center registries that incorporate standardised definitions, validated patient-reported outcome measures (PROM’s), and socioeconomic variable is essential. This will enable better comparison and help guide global best practices.

This scoping review demonstrates that megaprosthetic LSS provides durable oncologic control and reliable functional restoration for patients with primary or recurrent bone tumours. Functional outcomes were consistently favourable, particularly in distal femur reconstructions, with strong long-term implant survival across studies. Although complications such as infection, aseptic loosening, and mechanical failure persist, modern modular and silver-coated prosthetic designs combined with structured rehabilitation have markedly improved long-term results. Future progress will depend on multi-center collaboration, standardized outcome measures, and the integration of socioeconomic and rehabilitation factors into future research, ensuring that advances in implant technology translate into equitable, patient-centered improvements in mobility and quality of life.