Restoration of ambulation after internal hemipelvectomy using a three-stage reconstructive strategy: A case report and review of literature

Abstract

BACKGROUND

Internal hemipelvectomy profoundly alters pelvic biomechanics, often resulting in complex, multilevel deformities, including limb-length discrepancy, joint instability, and gait dysfunction. Management of complex late sequelae remains challenging. This report describes a staged reconstructive strategy used to improve ambulation in a patient with severe post-oncological deformities.

CASE SUMMARY

A 16 years old boy presented with severe deformities following childhood type I pelvic resection for Ewing sarcoma. Findings included a 10 cm limb length discrepancy, valgus malalignment, equinus contracture, and common peroneal nerve palsy. Imaging revealed pelvic deformity, acetabular dysplasia, and proximal femoral asphericity. A threestage management plan was implemented: (1) Ilizarov distraction osteogenesis, achieving 7.5 cm of tibiofibular lengthening; (2) Custom-made pelvic implant reconstruction with total hip arthroplasty; and (3) Correction of equinus deformity with additional lengthening and Hoke tenotomy. This strategy resulted in substantial improvement in limb alignment, weight-bearing capacity, and ambulatory function, although gait remained abnormal at final follow-up.

CONCLUSION

Sequential biological-prosthetic reconstruction may improve functional ambulation after internal hemipelvectomy in select patients.

Key Words: Internal hemipelvectomy; Ilizarov apparatus; Custom-made implant; Pelvic reconstruction; Limb-length discrepancy; Case report

Core Tip: Internal hemipelvectomy may lead to severe biomechanical disturbances that compromise gait and mobility. This report describes an uncommon case of long-term functional impairment following pelvic tumor resection that was successfully managed using a three-stage reconstructive strategy. Sequential use of distraction osteogenesis, custom pelvic reconstruction with total hip arthroplasty, and distal deformity correction resulted in significant improvement in ambulation. This case highlights the potential value of staged biomechanical optimization before definitive reconstruction in selected orthopedic oncology patients.

INTRODUCTION

Oncological bone resection, a key component in the treatment of skeletal neoplasms, often necessitates comprehensive prosthetic arthroplasty aimed at restoring musculoskeletal function and optimizing patients’ quality of life[1,2]. The removal of pathological bone segments requires advanced reconstructive techniques and a well-coordinated therapeutic strategy that integrates surgical intervention with intensive rehabilitation[3].

Among the surgical procedures used in the treatment of bone cancers, hemipelvectomy holds a special place. It is one of the most complex procedures, involving the resection of part or the entire hemipelvis, either without amputation of the lower limb (internal hemipelvectomy) or with limb amputation (external hemipelvectomy). The indications for this procedure include advanced malignant pelvic tumors, such as chondrosarcoma or Ewing sarcoma, that do not respond to standard treatment methods and that pose a life-threatening risk to the patient[3,4]. Various contemporary methods of reconstruction after oncological pelvic resections include the use of saddle prostheses, allograft-prosthetic composites, and custom-made implants, enabling anatomical reconstruction and restoration of musculoskeletal function[5-8].

Despite advances in reconstructive surgery, treatment following hemipelvectomy remains associated with a high risk of complications[9,10]. The most common include wound infection; shortening of the lower limb, which may lead to gait disturbances and secondary overload-related changes; loss of hip joint stability and function, resulting in limited range of motion and impaired mobility; and sciatic nerve or branch paralysis, particularly of the common peroneal nerve, which may result in foot drop and the need for orthotic support during ambulation[11-13]. These complications significantly affect the quality of life, as well as the duration and effectiveness of rehabilitation.

In this context, the Ilizarov apparatus, based on the biological principle of distraction osteogenesis[14], offers a unique reconstructive option following hemipelvectomy. Its use in both pediatric and adult patients remain uncommon[15], but it is particularly valuable in complex cases where traditional endoprosthetic reconstruction is not feasible owing to insufficient anatomical support or extensive bone and soft-tissue defects. The Ilizarov apparatus allows stabilization of bone segments during healing, correction of limb alignment, and gradual lengthening of shortened limbs - an approach that is especially important in children and adolescents with ongoing skeletal growth[16].

This report aimed to present a comprehensive orthopedic management approach in a patient following oncological pelvic bone resection, with a focus on reconstructive strategies employing the Ilizarov apparatus to improve lower limb function. By integrating the present case with the available literature, this report highlights effective strategies that may improve mobility and functional recovery in patients after internal hemipelvectomy.

CASE PRESENTATION

Chief complaints

A 16 years old boy presented to our clinic in 2017 with gait dysfunction, approximately 10 cm shortening of the right lower limb, valgus knee deformity, and equinus contracture of the right ankle associated with common peroneal nerve palsy.

History of present illness

At approximately 5 years of age, the patient was diagnosed with Ewing sarcoma of the right ilium and was treated with chemotherapy between 2005 and 2006. In May 2006, he underwent type I pelvic resection with implantation of a metal plate and bone allograft for acetabular reconstruction.

One month postoperatively, physical examination and radiographic evaluation revealed dislocation of the right femoral head, which was treated with immobilization in a hip cast. The patient was subsequently readmitted for postoperative infection and fistula formation within the surgical scar, receiving antibiotic therapy followed by fistula excision in December 2006.

Follow-up radiographs demonstrated partial dislocation of the femoral head and acetabular deformity. In May 2007, the patient was readmitted owing to recurrence of the fistula and underwent revision osteosynthesis with fistula debridement. At follow-up in 2008, based on bone marrow examination and radiographic evaluation, the patient was considered free of oncological disease. In 2009, he was admitted to the orthopedic ward with a fracture of the distal third of the right femur, which was treated conservatively with cast immobilization. Over subsequent years, progressive functional impairment became evident, including severe limb-length discrepancy, valgus malalignment, gait dysfunction, and equinus deformity. He was therefore referred to our clinic in 2017 for further reconstructive management.

History of past illness

Apart from the oncological history described above, no other major medical conditions were documented.

Personal and family history

The family history was unremarkable. The patient had no documented genetic disorders or prior musculoskeletal conditions before the diagnosis of Ewing sarcoma.

Physical examination

At presentation, the patient demonstrated a significant gait disturbance, with an approximate 10 cm shortening of the right lower limb. Valgus deformity of the knee and equinus contracture of the ankle were also observed. Neurological examination confirmed the presence of common peroneal nerve palsy.

Laboratory examinations

Routine laboratory tests, including complete blood count and inflammatory markers, were within normal limits. No abnormalities suggestive of oncological recurrence were identified.

Imaging examinations

At the initial outpatient visit, radiographic evaluation demonstrated pelvic deformity following resection, a flattened and misshapen acetabulum, and deformity of the proximal right femur with an aspherical femoral head (Figure 1A). The femoral head was described as laterally subluxated.

Figure 1 Imaging examinations. A: Radiograph obtained at initial presentation in 2017 demonstrating pelvic deformity following internal hemipelvectomy, acetabular dysplasia, and proximal femoral deformity with lateral subluxation of the femoral head. Fixation hardware, including a plate and screws from the previous pelvic resection, is visible; B: Radiograph demonstrating limb length discrepancy between the lower extremities and lateral deviation of the mechanical axis in both lower limbs; C: Radiograph demonstrating tibial and fibular lengthening using an Ilizarov external fixator; the first stage of treatment; D: Postoperative radiograph demonstrating total hip arthroplasty with a custom-made acetabular component and femoral stem; the second stage of treatment; E: Radiograph demonstrating an Ilizarov external fixator used for correction of equinus deformity, combined with Hoke tenotomy; the third stage of treatment; F: Final radiographic outcome demonstrating improved limb alignment and maintained implant position after completion of the three-stage reconstructive treatment.

Additionally, valgus alignment of both lower limbs was observed. Mechanical axis deviation was lateralized by 20 mm on the right side and 6 mm on the left. Limb length discrepancy was noted, with the right limb measuring 950.75 mm and the left measuring 1051.24 mm, corresponding to a discrepancy of approximately 100 mm (Figure 1B).

The lateral proximal femoral angle measured 52° on the right and 73° on the left. The joint line convergence angle measured 4° valgus on the right and 1° varus on the left (Figure 1B).

FINAL DIAGNOSIS

Post-oncological pelvic deformity following internal hemipelvectomy, associated with severe limb length discrepancy, valgus knee deformity, equinus contracture, and common peroneal nerve palsy.

TREATMENT

To address the patient’s complex condition and improve functional gait, a three-stage treatment plan was developed: Initial lengthening of the right lower limb using the Ilizarov apparatus, followed by total hip arthroplasty with a custom pelvic implant, and finally correction of the ankle deformity using the Ilizarov apparatus. The decision to initiate treatment with limb lengthening rather than primary total hip arthroplasty was based on biomechanical and reconstructive considerations. Severe limb shortening and malalignment significantly altered load distribution across the pelvis and hip joint. Performing total hip arthroplasty in the presence of pronounced limb-length discrepancy and axial deformity would have increased the risk of implant malposition, instability, and early mechanical failure. Gradual limb lengthening and axis correction were, therefore, prioritized to restore more physiological limb alignment and soft-tissue balance, creating optimal conditions for subsequent pelvic reconstruction and hip arthroplasty. The rationale for selecting the Ilizarov apparatus was based on its versatility and adaptability in complex limb reconstruction, as this method enables not only limb lengthening through distraction osteogenesis but also correction of multiplanar deformities, including angular and rotational malalignment, if required during treatment. This feature was particularly relevant in the present case, given the coexistence of limb shortening, valgus malalignment, and post-oncological anatomical alterations.

In 2018, the patient underwent surgical application of a lengthening Ilizarov apparatus. Over a 12-month period, the limb was lengthened by 7.5 cm (Figure 1C). The objective of this stage was tibial and fibular lengthening combined with correction of limb alignment to restore the mechanical axis before total hip replacement.

In 2019, the patient was admitted for total hip arthroplasty with pelvic reconstruction. Owing to severe pelvic deformity, particularly of the acetabulum, a custom-made implant was designed. The procedure was performed using the previous hemipelvectomy incision. The plate and screws from the initial resection were removed. Pelvic preparation was guided by a three-dimensional printed model of the patient’s pelvis. Subsequently, the custom-made acetabular component was implanted using screw fixation. Following resection of the femoral head, a standard femoral stem was inserted, and a dual mobility head was used to enhance joint stability (Figure 1D). The postoperative period was uneventful, and the patient was discharged from the hospital in good condition.

In 2020, the patient underwent an additional 6-month course of treatment with the Ilizarov apparatus to correct equinus deformity of the ankle, attributed to common peroneal nerve palsy. Simultaneously, the limb was lengthened by an additional 3 cm. Application of the Ilizarov apparatus, combined with multi-level Hoke tenotomy, resulted in correction of the deformity and achievement of 15° of ankle dorsiflexion (Figure 1E). The long-term clinical course and staged treatment sequence are summarized in Table 1.

Table 1 Chronological summary of the patient’s clinical course and three-stage reconstructive treatment following internal hemipelvectomy.

Date	Age	Clinical event
2005	5 years	Diagnosis of Ewing sarcoma of the right ilium
2005-2006	5 years	Chemotherapy
May, 2006	5-6 years	Type I pelvic resection with metal plate and bone allograft acetabular reconstruction
June, 2006	5-6 years	Postoperative femoral head dislocation treated with hip cast immobilization
December, 2006	6 years	Postoperative infection and fistula excision
May, 2007	6-7 years	Recurrence of the fistula and revision osteosynthesis with fistula debridement
2008	7 years	No evidence of oncological recurrence
2009	8 years	Distal right femoral fracture treated conservatively with cast immobilization
2017	16 years	Referred to our clinic due to severe limb-length discrepancy, gait dysfunction, valgus deformity and equinus contracture
2018	17 years	Stage 1 Ilizarov tibiofibular lengthening (7.5 cm) and mechanical axis correction
2019	18 years	Stage 2 pelvic reconstruction with custom implant and total hip arthroplasty
2020	19 years	Stage 3 correction of equinus deformity, additional 3 cm lengthening, Hoke tenotomy
2022-2025	21-24 years	Follow-up: Maintained alignment, no loosening, persistent mild deficits, independent ambulation

OUTCOME AND FOLLOW-UP

The three-stage treatment strategy resulted in substantial functional improvement, allowing the patient to ambulate with appropriate weight-bearing and without knee hyperextension (Figure 1F). Although gait remained abnormal at final follow-up, clear improvement in overall ambulatory function was achieved.

Functional outcome was assessed using the Musculoskeletal Tumor Society scoring system[2]. The score reached 80%, with component scores of 5/5 for pain, 5/5 for function, 5/5 for emotional acceptance, 3/5 for walking ability, 1/5 for gait, and 5/5 for supports. Despite persistent gait disturbances, the outcome aligns with the “excellent” functional category (24-30 points), representing a substantial improvement compared with the pre-treatment score of 43.3%, which fell within the “fair” functional category.

During serial outpatient follow-up through January 2025, accounting for approximately 5 years after the third stage of treatment, radiographs demonstrated maintained limb alignment and no evidence of implant loosening or mechanical failure. Some residual functional deficits persisted during follow-up, most notably muscle atrophy and limited ankle dorsiflexion. However, the patient remained independently ambulatory without routine assistive support. Ongoing physiotherapy was continued to support long-term mobility and functional performance.

DISCUSSION

Postoperative complications following internal hemipelvectomy remain a significant challenge in orthopedic oncology[9,10]. The complexity of the procedure, loss of pelvic continuity, and extensive soft-tissue dissection increase the risk of infection, instability, and neurovascular injury[17]. The most frequently reported complications in the literature include hip dislocation, infection, and limb-length discrepancy, as well as sciatic or common peroneal nerve palsy, which may lead to gait disturbances and functional deficits[11,12,17].

Contrary to most reports that focus on single-stage or limited reconstructive solutions after this procedure, our case demonstrates that a comprehensively planned biological-prosthetic strategy can significantly improve functional mobility despite serious postoperative sequelae. To our knowledge, reports describing staged limb reconstruction combining Ilizarov distraction osteogenesis with delayed pelvic prosthetic reconstruction after internal hemipelvectomy remain limited. In most previously published reports, reconstructive efforts after internal hemipelvectomy have primarily focused on restoration of pelvic continuity and establishment of a stable hip joint[18]. These objectives have typically been pursued using techniques such as hip transposition, structural allografts, endoprosthesis reconstruction, or allograft-prosthetic composites.

The limb length discrepancy and valgus deformity observed in our patient are well-documented sequelae of internal hemipelvectomy, especially in pediatric patients treated during periods of skeletal growth[13,15]. The available literature typically describes limb lengthening after hemipelvectomy as a complementary procedure to improve gait, often performed to a limited extent or at a later stage, with variable functional outcomes[13].

In contrast, our approach prioritized early mechanical reconstruction through staged distraction osteogenesis as the first stage of treatment. This strategy differs from approaches that recommend primary pelvic or hip reconstruction[3,5] and was directly related to the patient’s severe limb shortening and consequent impairment of load transmission. Correction of limb length and alignment before hip reconstruction improved soft tissue balance and optimized biomechanical conditions for subsequent arthroplasty, establishing a clinically meaningful temporal association between staged correction and functional improvement.

Custom-made pelvic implants have become a preferred option for acetabular reconstruction following oncological resections, offering better anatomical congruence and fixation compared with saddle or modular prostheses[6-8,19,20]. The successful integration of the custom-made acetabular component in our patient is consistent with recent reports demonstrating improved stability and functional outcomes using three-dimensional printed implants[19]. However, in contrast to most reported cases, pelvic reconstruction in our patient was performed more than a decade after the initial hemipelvectomy. This prolonged interval represents a significant deviation from standard practice and highlights the feasibility of delayed reconstruction when preceded by appropriate biomechanical preparation.

A dual-mobility acetabular cup was used, providing articulation with both the femoral head and the acetabulum, creating two effective points of mobility[21]. This design further reduces the risk of dislocation associated with impaired soft tissue support and neuromuscular deficits. This approach is consistent with evidence supporting the use of dual-mobility systems in high-risk patients and in revision total hip arthroplasty[21-24].

The Ilizarov apparatus, traditionally used for limb lengthening and correction of complex deformities, has also shown significant value in orthopedic oncology[25], particularly in patients with limb shortening, instability, or secondary deformities after tumor resection[16,26]. Based on the principle of gradual distraction osteogenesis, it enables controlled bone regeneration, correction of limb malalignment, and minimization of soft tissue tension - an important consideration in postoperative cases where anatomical integrity is disturbed and biological healing capacity is impaired[14,25].

Although most oncologic reconstructions focus on proximal segments and gait compensation with orthoses, residual distal deformities, such as equinus contracture, may significantly limit functional recovery and weight-bearing capacity if not treated appropriately[27]. Reported Ilizarov-based techniques for distal correction include gradual external fixation, multilevel tenotomy, and tendon transfers, which enable gradual correction of the deformity while maintaining soft-tissue integrity[28,29].

In the present case, the use of the Ilizarov apparatus combined with Hoke’s multilevel tenotomy enabled effective correction of the equinus contracture and additional limb lengthening, which translated into lasting functional improvement without recurrence, representing a viable alternative to isolated soft-tissue procedures.

A key advantage of the Ilizarov system is its high degree of flexibility during treatment, allowing dynamic modification of distraction rate, correction plane, and extent of deformity correction without the need for additional surgical intervention[14,30]. This adaptability was particularly important in the present case, given the complex and biomechanically evolving clinical situation, in which stepwise optimization of the limb alignment and length was required before final reconstruction. Moreover, in contrast to intramedullary limb-lengthening devices, the Ilizarov apparatus is not limited by the diameter of the medullary canal, patient age, or prior oncologic procedures. The absence of internal implants helps to avoid implant-related complications such as nail fracture, magnetic mechanism failure, or the need for secondary removal procedures[31]. Alternative limb-lengthening techniques, including motorized intramedullary systems such as the PRECICEÔ nail (Globus Medical, Audubon, PA, United States), may be considered in select patients. However, in the present case, the Ilizarov device was chosen owing to its biomechanical versatility, safety in complex anatomical conditions, and our center’s extensive experience with this type of system. This approach enabled precise planning, controlled execution, and ongoing modification of treatment throughout the reconstruction process[14,30].

Several limitations of this case report should be acknowledged. First, as this was a single-patient observation, generalizability of the findings is inherently limited. Second, objective functional outcome measures, such as validated gait analysis scores or patient-reported outcome measures, were not systematically recorded, restricting quantitative comparison with existing series. Third, the prolonged treatment duration and requirement for multiple surgical stages may not be feasible in all clinical settings, thereby limiting the broader applicability of this approach. Furthermore, the success of the Ilizarov method is highly operator-dependent and closely related to institutional experience, which may introduce variability in clinical outcomes across different cases or treatment centers.

This case illustrates the substantial improvement in mobility achieved through a carefully planned, three-stage reconstructive strategy combining distraction osteogenesis, patient-specific pelvic reconstruction, and correction of distal limb deformities. The uniqueness of this report lies in the integration of biological and prosthetic techniques in a long-term, staged treatment process for a patient with severe deformities following internal hemipelvectomy. Based on this experience and the available literature, staged biomechanical optimization may be considered before definitive pelvic reconstruction in selected patients with severe limb-length discrepancy accompanied by axial malalignment. Although further studies are required to establish optimal sequencing and patient selection criteria, this case supports the feasibility and potential value of individualized, multistage reconstruction following internal hemipelvectomy.

CONCLUSION

In conclusion, the presented case demonstrates that reconstruction and deformity correction following internal hemipelvectomy may require a multistage treatment strategy, yet can achieve satisfactory functional outcomes. Pelvic reconstruction should ideally be planned simultaneously with hemipelvectomy whenever feasible. However, even when not performed at the initial stage, as illustrated in this case, a carefully planned and staged reconstruction strategy may result in meaningful functional improvement of the lower limb.