Multistage Additive Manufacturing for Complex Limb Bone Deformity Reconstruction (MAP-BD)
Clinical Validation of a Multistage Additive Manufacturing Pathway for Complex Limb Bone Deformity Reconstruction
Complex deformities of the limb bones may involve abnormal angulation, limb or bone shortening, abnormal rotation and structural bone loss. These deformities can result from previous trauma, bone nonunion, infection, tumour resection, congenital or developmental conditions, previous surgery or failed reconstruction. Treatment is challenging because correction of the deformity and reconstruction of the remaining bone defect often require several coordinated surgical stages.
This multicentre prospective observational cohort study will evaluate the clinical outcomes of a multistage treatment pathway that incorporates three-dimensional imaging, computer-assisted surgical planning, additive manufacturing and patient-specific porous Ti6Al4V implants. Treatment decisions and the selection of surgical procedures will be made by the treating multidisciplinary team according to each patient's clinical condition and will not be assigned by the study.
The study will include 30 adults with complex deformity of a major upper- or lower-limb bone. Participants will be followed for 12 months after definitive reconstruction. The study will evaluate maintenance of deformity correction and implant stability, restoration of bone length, angular and rotational correction, radiographic bone-implant integration, limb function, pain, progression to functional loading, reoperations and adverse events.
Study Overview
Status
Detailed Description
Complex limb bone deformities may arise from post-traumatic malunion or nonunion, infection-related sequelae, tumour-related bone resection, congenital or developmental abnormalities, iatrogenic deformity or failure of previous reconstruction. Affected patients may have shortening, coronal or sagittal angulation, axial rotational deformity and structural bone deficiency, frequently accompanied by compromised soft tissue and multiple previous operations. Successful reconstruction therefore requires restoration of bone length, alignment and rotation, together with reconstruction of a stable skeletal column.
This is a multicentre, prospective observational cohort study involving 30 adult participants. The study will observe patients who receive a multistage additive manufacturing pathway as part of their clinical care. Eligibility for treatment and all clinical decisions, including the timing and type of surgery, will be determined by the treating multidisciplinary team independently of study participation. The study will not randomise participants, assign treatment or mandate a comparator procedure.
The clinical pathway may comprise three principal stages. The first stage consists of aetiology-specific preparation and definition of the reconstructive defect. Infection-related cases may require radical debridement, deep-tissue microbiological sampling, temporary stabilisation and antimicrobial treatment. Tumour-related cases may undergo oncologically appropriate resection. Patients with aseptic malunion, nonunion, developmental deformity or failed previous reconstruction may undergo corrective osteotomy, implant removal, nonunion-site preparation, soft-tissue release or other clinically indicated procedures.
The second stage consists of three-dimensional deformity analysis and restoration of bone length, alignment and rotation. Thin-slice computed tomography and calibrated radiographs will be used to construct a patient-specific anatomical model and quantify shortening, coronal and sagittal angulation, axial rotation and the anticipated bone defect after correction. Angular and rotational deformities may be corrected acutely when permitted by neurovascular and soft-tissue conditions. Patients with substantial shortening, multiplanar deformity or soft-tissue contracture may undergo gradual distraction and correction using circular or monolateral external fixation.
The third stage consists of definitive patient-specific reconstruction. After the planned correction has been achieved and the treating team confirms that the patient is ready for reconstruction, a porous Ti6Al4V implant will be designed for the corrected anatomy and manufactured using additive manufacturing. Patient-specific guides may be used to transfer the virtual plan to surgery. The implant will be stabilised using an intramedullary nail, locking plate, screws, integrated fixation structures or a combination selected according to the anatomical and mechanical requirements.
Postoperative rehabilitation will be individualised according to soft-tissue healing, bone quality, fixation stability and radiographic findings. Lower-limb participants will progress from protected or partial weight-bearing to full weight-bearing, whereas upper-limb participants will progress from protected motion to unrestricted functional loading.
Clinical and imaging assessments will be performed at baseline, during treatment and approximately 1, 3, 6 and 12 months after definitive reconstruction. The study will evaluate the clinical success and safety of the complete pathway, including correction accuracy, implant stability, radiographic bone-implant integration, limb-specific function, pain, health status, functional loading, reoperations and adverse events.
Study Type
Enrollment (Estimated)
Contacts and Locations
Study Locations
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Beijing Municipality
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Beijing, Beijing Municipality, China, 100191
- Peking University Third Hospital
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Participation Criteria
Eligibility Criteria
Ages Eligible for Study
- Adult
- Older Adult
Accepts Healthy Volunteers
Sampling Method
Study Population
Description
Inclusion Criteria:
- Age 18 years or older. Complex deformity involving a major upper- or lower-limb bone, including the humerus, radius, ulna, femur or tibia.
Angular deformity, shortening, rotational deformity or any combination of these.
Structural bone deficiency present before treatment or anticipated after corrective osteotomy, debridement or bone resection.
The treating multidisciplinary team determines that a patient-specific additively manufactured implant is clinically indicated to restore skeletal continuity, length, alignment, rotation or mechanical load transfer.
Ability to undergo CT-based three-dimensional planning and the planned multistage reconstructive treatment.
Ability to provide written informed consent and willingness to complete 12 months of follow-up after definitive reconstruction.
Exclusion Criteria:
- Isolated osteoarthritis-related deformity without a reconstructive limb bone defect.
Acute fracture without an established deformity or structural bone deficiency requiring patient-specific reconstruction.
Uncontrolled systemic infection. Severe vascular insufficiency or a soft-tissue condition that precludes definitive reconstruction.
Anticipated inability to achieve adequate debridement when required, viable soft-tissue coverage or stable fixation.
Known allergy or contraindication to the implant material. Pregnancy when the required imaging or surgery would be inappropriate. Inability to comply with rehabilitation or outcome assessments. Participation in another clinical study that could materially affect the study outcomes.
Study Plan
How is the study designed?
Design Details
Cohorts and Interventions
Group / Cohort |
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Multistage Additive Manufacturing Reconstruction Cohort
Adults with complex deformity of a major upper- or lower-limb bone who undergo a multistage additive manufacturing reconstruction pathway as part of routine clinical care.
The deformity may include angulation, shortening, abnormal rotation and structural bone deficiency and may result from post-traumatic malunion or nonunion, infection-related sequelae, tumour-related resection, congenital or developmental conditions, iatrogenic deformity or failed previous reconstruction.
The clinical pathway may include aetiology-specific preparation, CT-based three-dimensional planning, corrective osteotomy, acute or gradual deformity correction, patient-specific surgical guides, and definitive reconstruction using a patient-specific additively manufactured porous Ti6Al4V implant with individualised fixation.
Treatment decisions are made independently by the treating multidisciplinary team.
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What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
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Percentage of Participants With Clinical Reconstruction Success
Time Frame: 12 months after definitive reconstruction
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Clinical reconstruction success is a composite outcome requiring all of the following criteria: (1) the patient-specific implant remains in situ without removal or component revision for mechanical failure; (2) no deep infection or other aetiology-specific event requires implant removal or unplanned major reconstruction; (3) radiographs show a stable implant and fixation construct without clinically important migration, subsidence, implant fracture, fixation failure or progressive loss of correction; and (4) the reconstructed limb permits functional use appropriate to the anatomical region.
Participants meeting all four criteria will be classified as having clinical reconstruction success.
The number and percentage of participants meeting the composite outcome will be reported.
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12 months after definitive reconstruction
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Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
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Percentage of Participants Achieving the Planned Deformity Correction
Time Frame: Within 1 month after definitive reconstruction
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Achievement of the planned deformity correction will be assessed by comparing postoperative CT or calibrated radiographic measurements with the patient-specific virtual plan.
Correction will be classified as successful when all applicable criteria are met: residual length deviation of 10 mm or less, coronal and sagittal angular deviation of 5 degrees or less, and axial rotational deviation of 10 degrees or less.
Only deformity components present and included in the preoperative plan will be evaluated for each participant.
The number and percentage of participants meeting all applicable correction criteria will be reported.
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Within 1 month after definitive reconstruction
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Collaborators and Investigators
Sponsor
Study record dates
Study Major Dates
Study Start (Estimated)
Primary Completion (Estimated)
Study Completion (Estimated)
Study Registration Dates
First Submitted
First Submitted That Met QC Criteria
First Posted (Actual)
Study Record Updates
Last Update Posted (Actual)
Last Update Submitted That Met QC Criteria
Last Verified
More Information
Terms related to this study
Keywords
Other Study ID Numbers
- AM-2608
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
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