OpenSurgiSim is a surgical training system developed by AlgoSurg and Center for Limb Lengthening & Reconstruction for orthopaedic surgeons to learn all the steps of accurate correction of bone deformities. AlgoSurg Inc., USA has been developing many innovative technologies for variety of bone surgeries, specially for lower-limb. The CLLR, Mangal Anand Hospital, Mumbai, India is renowned for its advanced approach to limb lengthening and reconstructive/deformity surgery and research. Together both the organisations developed and clinically tested OpenSurgiSim to bring the best practices of deformity correction surgeries in a form of training system.

  • 00:05 Introduction
  • 00:44 Problem Statement
  • 02:15 Solution
  • 03:10 Components of OpenSurgiSim

Problem[edit | edit source]

One of the major part of orthopaedic surgeries is about correction of deformities, however, currently there is not enough exposure and training in the planning and execution of deformity correction surgery especially in the LMICs. It is estimated that around 20-30% of bone deformity correction surgeries need to undergo revisions [1; 2, 3]. This is mainly due to the lack of expertise in the field. In fact, the number of expert surgeons that exist today is only 10% of the overall requirement and also there are just not enough trainers (we performed an extensive survey of more than 250 surgeons across the world, especially in LMICs). To acquire expertise in the surgery, a trainee surgeon has to work for years under supervision of highly expert surgeons (which are scarce resources). Since there is no training simulator available for complex deformities, the trainees need to assist in real-patient surgeries with the expert surgeon (even the cadavers are not much available for these kinds of cases). Even in the high-resource settings, specially designed mock bones are used in addition to real-patient surgeries but always under expert surgeon's guidance. Because of this dependency of less available expert trainers and scarcity of resources, there are only few trained deformity correction surgeons in the world, especially in the low-resource settings, where most of the complex cases occur. In addition, there is no specific training available in the medical school curriculum of India and other developing countries, for sub-specialities like complex deformity corrections [4,5]. Due to the very small surgeon to patient ratio, the surgeons are so busy that they do not even get an opportunity to improve their skills in complex surgeries and so they need a training simulator that is faster, easier to set up and independent of any expert trainer.


The surgeons at low-resource settings (LMICs) who are not well trained for complex deformity corrections either send the patients to the expert surgeons at high-resource settings or they under-perform in the surgery which has to be revised by expert surgeons later, adding extra cost to the patient while reducing their life-style quality. This also adds a huge workload on the expert surgeons. In addition, there is a lack of standardization in both training and procedures of orthopedic surgeries in general, and much more in specialities like complex deformity correction, leading to a very poor patient outcome.

Correction of deformity needs an understanding of the various principles involved and the normal anatomy in the lower limb, especially regarding the various axes and joint orientations. Firstly, this understanding and principles has to be applied to plan the surgery pre-operatively, using patient's X-ray images. Secondly, it needs a step wise approach for physical application of the preoperative plan, correcting the bone deformity and application of specific implants (rail-fixator in this training course). These psychomotor skills are mainly involve geometries, positions, orientations etc. A good basic understanding of the principles and regular application of these principles during surgery, is required to improve a surgeon's skills in correcting bone deformities.

Solution[edit | edit source]

To solve the above problem, we created OpenSurgiSim to train any trainee or junior orthopaedic surgeon to get expertise and confidence herself/himself, in complex bone deformity corrections. The OpenSurgiSim has following characteristics:

1) Surgeries - The current version of OpenSurgiSim training module is for surgeries involving complex bone deformity correction using external fixation which covers a large number of bone surgeries in LMICs.

Further versions will also have additional modules in the same platform to cover fractures (largest pool of bone surgeries), deformity correction using internal fixation (modern techniques) as well as advance complex bone deformities (very few surgeons can do these currently).

2) Trainee profile and course - The module is designed for Junior or Trainee Orthopedic Surgeons.

3) Comprehensive training - Each trainee will go through all the aspects of bone deformity corrections as given below, on around 20 unique real-patient case-studies for planning training and 10 (multiplied by 2 for practice) case-studies for psychomotor training.

  • Pre-operative planning of the surgery using digital x-ray images

    - Diagnosis and problem assessment

  • Correction planning and determining surgical parameters - Every step of psychomotor skill involving the bone;

    - Accurately drilling onto the bone for placement of fixator,

  • Accurate fixation of external rail fixator-pins,
  • Accurate bone resection,
  • Accurate correction and placement of the external-fixator. All of this will be trained on a number of carefully selected unique case-studies (not just one bone case).

4) Training on real case-studies - The pre-operative planning and psychomotor training is given through range of real-patient cases and delivered, guided and monitored through a cloud-software named OpenSurgiSim. The OpenSurgiSim software guides and facilitates the pre-operative planning of real-patient cases using their digital X-ray images. The same software guides the trainees as well as tracks and measures their performance (through a web-camera attached to computer), while the trainee learns the psychomotor skills using 3D-printed bone models (made available as a modular kit) which also match the real patient bone in geometry and structure.

5) Accessible and Reproducible - OpenSurgiSim is available online as a cloud-software so that it can be accessed by trainees anywhere, anytime, free of cost, in a same standard form every-time (standardised and replicable), designed especially for the LMICs. The list of the rest of the training equipment and 3D files+instructions is given in Appropedia. The 3D printed bone models and instructions are designed in such a way that any local 3D printing manufacturer in the world can print them easily. The training equipment like web-cam, table clamp, rail-fixator etc. are widely available world-wide and just need to be ordered online (links given). For example, we chose Logitech C-270 camera which is the most popular and available world-wide. These equipment also do not have any constrained specifications (for wide range of availability).

6) Unique Self-assessment system - Since the module is designed for trainee surgeons in LMICs which have scarcity of expert trainers, we developed a special self-assessment system within the module. The self-assessment system is Real-time, Automatic and Unbiased.

Real-time -Trainee needs to be trained for each step in detail. Hence, OpenSurgiSIm trains a surgeon without a need of any expert-trainer. The guidance and assessment both, during the training is done by the OpenSurgiSim system in real-time. Trainees progress and performance is recorded in real-time and stored in cloud.

Automatic - The trainee should focus only on training and not on measuring his/her own performance and hence the assessment component is made automatic. The assessment is designed in such a way that it does not interfere with the training process.

Unbiased - The performance measurement should not be biased and follow known standards. Hence, the performance measurement and assessment in the psychomotor training sub-module is done automatically by object-tracking algorithm which produces robust results without any cognitive human bias (human bias happens in traditional methods of assessment by an expert or trainee herself/himself). Similarly, the performance measurement in the pre-operative planning training sub-module is done by selecting correct answers based on certain quantitative parameters measured by the software (angles/distances/options).

7) DIY training-kit and NOT DIY fabrication kit - We believe that the skills, time and efforts of the trainee (whose specialities are only clinical) should be spent only on the training and not on fabricating the training module. Hence, OpenSurgiSim is NOT a DIY-fabrication kit; it is a DIY-training kit. The training module can be used even by an individual surgeon independently as well, not just a full organisation, without a need of any special technical or engineering skill. The assembly of the kit (for psychomotor training module) is super-easy like fixing a table clamp, mounting a web-cam or joining two bone parts (need to be done only once and then practice all the case-studies in the same setup).

This low-cost and easily reproducible training system aims to increase the number of orthopaedic surgeons who can proficiently and confidently perform these surgeries in low and middle income countries, where there is limited access to this expertise. Thus, more patients will have access to experts in their own communities.

OpenSurgiSim Training[edit | edit source]

Access and requirements[edit | edit source]

OpenSurgiSim, being a cloud-software, can be easily accessed anywhere anytime via a computer connected to the internet, at To use the software for the training, a trainee has to signup and create an account. Once signed up, the user can login anytime and undergo training. All the information and progress of the training is automatically stored in the cloud. For the psychomotor training, the trainee will need a web camera, a few clamps/fixtures to create a training-setup. The trainee will also need basic clinical-tools for drilling & cutting the mock bones (either an orthopaedic power drill or regular battery operated drill can be used). The mock bones will be acquired by 3D printing a modular kit. The parts of the kit can be assembled to form various deformed bones for different case-studies. The kit is smartly designed to re-use many parts and save the cost of 3D printing by more than 60%.

More information on accessing the software and computing hardware requirements can be accessed here. A special access for Demo or Evaluation purpose is also explained in this page: Accessing OpenSurgiSim.

Prerequisite Didactic Component - Basic principles of Deformity Correction[edit | edit source]

This includes a variety of reading material and videos to teach the basic principles of deformity correction. The reading material is gleaned from various authentic sources. The material is easy to understand and includes schematic diagrams and annotated video. It is advised that the trainees should go through this material at least once, before they attempt the training on OpenSurgiSim.

The material can be accessed at: Basic Principles of Deformity Correction

Once the trainees have gone through the basic reading material, OpenSurgiSim software can be accessed at

Step 1 - Pre-operative surgery planning training[edit | edit source]

This part of the OpenSurgiSim is to train surgeons to perform surgery planning of complex lower-limb bone deformities using digital X-ray images, through many case studies. For this, a special surgery planning software is created for the trainees. The surgery planning involves assessing the deformity and determining the surgical steps (planning) required to correct the deformity, using unique and carefully selected real-patient x-ray images. This training is given through two sub-modules - Guided and Non-Guided Surgery Planning Sub-Modules. The Guided Planning include set of real-patient x-ray case studies that are already planned by Expert Trainer surgeons. The trainee can follow the step-by-step guidance displayed on the screen to perform the planning. The Non-Guided Planning include set of case studies where Trainee surgeon has to plan the cases herself/himself without any guidance. At every critical step of the planning, the software will ask questions to assess the trainee performance and calculate the score for the case.

More information on how to use the surgery-planning sub-modules of OpenSurgiSim can be accessed here: OpenSurgiSim Surgery Planning Module User Guide

Step 2 - Psychomotor training[edit | edit source]

This is the most important part of the training which will train the surgeons to perform surgeries on to 3D printed bone models through many case-studies. This part of the OpenSurgiSim system is to train surgeons to apply the principles and the skills of determining the surgical knowledge/parameters during the planning case-studies onto a number of physical bone models based case-studies. This includes assessing the deformity, drilling and fixing the rail-fixator pins on specific position and orientation onto the bone, resection of the bone on planned position+orientation and finally assembling the rail-fixator implant onto the pins accurately to achieved the final desired bone correction. This training will be given through two sub-modules - Guided and Non-Guided Psychomotor Sub-Modules. In the guided training, the trainee will perform the deformity correction following the step by step instructions and the AR-based guidance system will provide real-time feedback and augmented guidance to the trainee. In the non-guided training, there will be no AR-based guidance.

More information on how to obtain the mock bone models, the clinical-tools, the training-setup tools, and how to use the psychomotor training sub-modules of OpenSurgiSim can be accessed here: OpenSurgiSim Psychomotor-AR Surgery Training Module User Guide

Self-assessment framework[edit | edit source]

The Self-Assessment component is integrated with all the sub-modules mentioned above: Surgery-planning and Psychomotor Training (guided and non-guided). It consists of automatic performance measurement for all the sub-modules as well as the scoring system and performance analysis, which helps the trainee surgeons to self-assess how well they have learned as they go through each stages of Guided Surgery-planning and guided Psychomotor training. It also helps them to self-assess how they perform under the Non-Guided Surgery-planning and Psychomotor sub-modules through the smart automatic scoring system which has been developed after benchmarking the scoring system with respect to the skills of Expert Trainer surgeons (this benchmarking will be finished once a few experts will undergo the OpenSurgiSim training). The performance measurement is based on responses by the trainee to the questions asked in each planning case-study as well as the automatic error measurement in drilling, cutting and deformity correction in each psychomotor case-study. Based on the scores of each case-study, the overall score, score varying with training completion, comparison with expert scores (will be finished once many users use OpenSurgiSim) and category score is presented to the trainees, for methodological improvement in their training pathway.

How the performance is measured and shown to the trainee for the Surgery-Planning sub-module is given here.

How the performance is measured and shown to the trainee for the Psychomotor-Training sub-module is given here.

More information on how to the analysis of the performance scores are presented to the trainee for self-assessment is given here: OpenSurgiSim Assessment Framework

Innovation[edit | edit source]

OpenSurgiSim is built on innovations with cutting edge technologies like cloud computing, object tracking, augmented reality, 3D printing and graphics not only to create significant improvements over the traditional approaches of the training but to bring the ultimate goal into reality which is "How to make bone surgeries better".

How OpenSurgiSim is better than traditional approaches[edit | edit source]

Traditional approach of training OpenSurgiSim
1. Access According to our survey of more than 200 surgeons across the world especially from low-resource settings of India and Africa, the traditional trainings are done through physical workshops which are accessible to only a few surgeons in limited regions (around 30 participants per workshop conducted at most twice a year in big cities). Cloud technology enabled online platform (apart from Appropedia), accessible to anyone, anywhere and anytime with basic internet, computer, web-cam and a few readily available equipment; without a need of an expert trainer with no need of a special facility (even at home).
2. Guidance and Feedback - Manually done by expert, hence limited by time and effort. An expert trainer can guide and give only observational feedback to a limited number of trainees for a few steps occasionally. - Automated and hence every step of the training is tracked and communicated to trainee in detail for real-time guidance
- No real-time feedback to improve learning - Object tracking and Augmented reality system gives real time quantifiable feedback to the trainees for every step
3. Self-Assessment - Manual - Can never asses performance for all the participants in detail for every step of surgical training - Automated system and hence performance of every step of the training is measured in quantifiable terms and communicated to trainee in real-time
- Non standardised - No standard method to assess the performance; based on intuition and experience of the trainer - Same standard of performance measurement for every trainee (unbiased)
- Inaccurate - Not quantifiable or measurable; Only by observation by an expert - Accurate quantifiable measurements of performance like accuracy in drilling angle or position etc.
- Uninterpretable - The limited assessment by the trainer can not be analysed to form an improved pathway of the training - All the performance scores of each step is presented with detailed analysis to guide trainees to improve training pathway
- Completely dependent on expert trainer - Self-assessment because of object tracking technology
4. Reproducibility Each trainer and training workshop can differ in training pathway, course, guidance, performance measurement and assessment according to the trainer, location, facility. As an online software its is accessed everywhere in the same form through internet. Hence the training case-studies and the algorithms which trains, guide and assess are same everywhere every-time. The required equipment are standard, and their specification requirements has wide range which do not affect the training performance.
5. Data storage and management There is no recording of performance data or assessment analysis. Hence, no way to ensure whether the trainees are practicing the appropriate skills; modify their performance to improve competence; and determine when they have practiced to a sufficient level of mastery to perform the procedure in a patient Includes Assessment Analysis sub-module which:
  • Records performance of each and every step of training (No need of maintaining any logbook)
  • Categorizes the performance scores (showing which part is better trained and which need more practice)
  • Presents comparison to expert scores
  • Presents time-wise improvements in scores
6. Completeness - Can train only a few basic case studies. - Cloud storage technology enables inclusion of multiple (around 10-20) carefully selected unique case-studies to practice.
- For detailed training over the months, a few trainees can join some rare training hospitals headed by very few expert trainers. - The full course available to anyone anywhere anytime like a personal trainer.
7. Scalability - A few hours workshop is organised with limited case studies. - Designed to add or update any new case-study of surgery-planning or psychomotor training (this ability is currently only with Admin Accounts)
- Different training workshops for different surgical practice - Designed as a one-stop solution platform for training on many other orthopaedic surgeries like Fractures, Bone plate surgeries etc.
8. Value for money - Cost of conducting workshop is high and for a group - Accessing the module is free of cost, like an online personal trainer for everyone anywhere
- One workshop can train at most 30-50 trainees (and inefficiently) - This one module can train any number of trainees anywhere anytime
- Cost of hiring the expert trainer is high. - No need of expert trainer and hence no hiring cost
- Trainee also has to travel to the workshop site usually in big cities - Trainee do not need to spend on travel
- Trainee has to pay for the workshop of few hours - The cost to be paid is for only for some equipment which will stay with the trainee forever.
  • The clinical tools and fixator implant used in the training are real and can be used in real patent surgery. Alternately, existing tools can be used to reduce the cost to trainee.
  • Physical bones are made modular to reduce cost of bone models.
- Trainee pays for a few hands-on training on limited cases (1 or 2) - More than 20 planning cases training free of cost and more than 20 psychomotor case-studies for very low cost.
  • Trainee has an option to train on less number of case-studies and reduce overall cost significantly (since major cost is the 3D printed bone models)
- Trainee can not take any training equipment for further review/use/practice - Practice multiple times/improve scores. Many case studies to practice on with the same system.
- Trainee need to pay separately for every other surgical training - The same setup and equipment will be used for other additional surgical training modules (planned for final phase - Fracture reduction of lower-limb bones, Bone plates based internal fixation for deformity correction and Multiapical and Multiplanar lower-limb bone deformities)

Why OpenSurgiSim will make surgeries better[edit | edit source]

We aim to build OpenSurgiSim to make surgeries better and for that we focus on its self-assessment system. Every orthopedic surgery done by every surgeon has to have same standard clinical outcome. Currently the surgeon's skill varies because of lack of training, lack of standard in training and lack of standard in measuring their performance. OpenSurgiSim is built to train a surgeon in the same standard way, measure the performance in the same standard way and assess the performance in the same standard way and in terms of quantifiable terms. These kinds of standards in training will produce surgeons with required and standard level of expertise, competence and confidence which will lead to perfect surgeries. And for this purpose, we built the self-assessment system as AUTOMATIC, REPRODUCIBLE and UNBIASED and this is ensured by innovations like Cloud-software (reproducible module performance), Augmented-Reality (real-time accurate training feedback) and Object Tracking (accurate performance measurement and analysis) in the OpenSurgiSim.

Evaluation[edit | edit source]

While building the OpenSurgiSim, we performed many concept discussions with GSTC experts, technical trials and clinical trails. Detailed iterations of the building and testing with results causes and improvements are given here:

Development Iterations already performed (Jan 2021 to Oct 2021)[edit | edit source]

Version Month Details Test Observation Update
1.1 FEB Prerequisite Didactic Component - Basic principles of Deformity Correction:

Appropedia pages on basic theory material

Tested by 1 expert trainer
  • Text and schematics are good but videos will improve learning
  • Added annotated videos for each principle of deformity correction; acquired from real training workshops performed by expert trainer
  • Also shows trainee interactions, questions, doubts and solutions
1.2 APR Surgery-Planning Training Sub-Module:

Developed surgery planning sub-module as step-by-step guidance of planning on bone pictures; so trainees can follow on photocopy of given bone pictures available on OpenSurgiSim software as case studies

Tested by 1 expert trainer and 1 Trainee on sample case-studies with supervision
  • More effort on physical aspects and less on learning
  • Need to get print bone images
  • Need to maintain physical records
  • Manual self-scoring
  • Large time-consumption
  • Assessment interferes training
  • Developed digital planning on digital X-rays with annotation tools and assessment questions in digital form
  • No need of printing the bone images
  • Real-time auto recording and saving of planning
  • Automatic scoring and saving
  • Super-fast
  • All focus on training, software takes care of the rest
1.3 MAY Surgery-Planning Training Sub-Module:

Updated as per the feedback from the last iteration

Tested by 2 expert trainers

and 3 Trainee on all case-studies without supervision

  • Bone pictures not same as real-patient X-rays
  • Every-step of planning need highlights and annotations for focus
  • No feedback based on mistakes
  • Trainee is just following the trainer guidance, how to test without guidance
  • Included 20 unique real-patient X-rays case-studies by expert trainer
  • Added animations and dialogues
  • Final scoring chart shows performance of each step and link to go back and observe
  • Added Non-Guided Sub-Module of Surgery Planning
1.2 MAY Psychomotor Training Sub-Module:

Surgery on 3D printed bones, 30 case studies (10 guided; 20 non-guided) Web-cam view of the training surgery on OpenSurgiSim software Object tracking and AR guidance

Tested by 1 expert trainer and 1 Trainee on sample case-studies with supervision
  • Large bone volume and cost due to many cases
  • Bone should have hollow inside; trainee should feel two cortex walls while drilling
  • Bone stability while drilling
  • Made modular design (reusable parts of bone joined together); reduced cost and volume by 60%
  • Made bones hollow for two cortex walls; reduced cost further
  • Developed fixture and updated design for more stability
1.3 AUG Psychomotor Training Sub-Module:

Updated as per the feedback from the last iteration

Tested by 1 expert trainer and 1 Trainee on sample case-studies with supervision
  • The object tracking marker not recognised sometimes
  • Lighting conditions need to be modified
  • Accuracy of object tracking
  • Replaced small composite marker with single big marker facing camera
  • Light equipment added with a calibration step in the module
  • Performed marker detection testing (achieved within 1mm and 1 deg)
2.1 OCT Psychomotor Training Sub-Module:

Updated as per the feedback from the last iteration

Tested by 1 expert trainer and 1 Trainee on sample case-studies without supervision
  • Text based instructions require too much effort
  • Performance measurement in the middle of surgery interferes the process
  • Added pictorial instructions, easy and fast to follow
  • Kept all the performance measurements in the end of surgical steps, at once; faster training

Development Iterations to be performed (Nov 2021 to Dec 2021) - Before we perform Clinical Evaluation of the Final Phase[edit | edit source]

Version Month Details Test
2.2 NOV Prerequisite Didactic Component - Basic principles of Deformity Correction:

Number of trainees will learn the theory at Appropedia without supervision

  • Will be tested by 5 Trainees
  • Knowledge on Basic principles will be assessed
2.2 NOV Surgery-Planning Training Sub-Module

and Psychomotor Training Sub-Module Training on All the case-studies without supervision Correction Rotation and Translation measurements and scores will be enabled New fabrication technique for the physical bone models

  • Will be tested by 3 Trainees
  • Performance scores will be assessed by experts and compared to the assessment given by the software
  • Feedback will be recorded
  • Enabled rotation and translation error in deformity as well
  • Continuous research going on with manufacturing company
2.3 DEC Surgery-Planning Training Sub-Module

and Psychomotor Training Sub-Module Will be updated as per the feedback from the last iteration Training on All the case-studies without supervision

  • Will be tested by 2 Trainers
  • Trainer benchmark scores will be established (to determine the acceptable performance level)
  • Will also be tested by 3 Trainees
  • Performance scores will be assessed by experts and compared to the assessment given by the software
  • Feedback will be recorded
  • Reports will be published here

Team and roles[edit | edit source]

OpenSurgiSim Team
Member Name Role
Dr. Vikas Karade Team Lead, Technical Lead
Dr. Mangal Parihar Education Lead and Clinical Lead
Amit Maurya Technical Co-lead
Dr. Manish Agarwal Clinical and Education Expert

Pages by OpenSurgiSim team[edit | edit source]

This is the list of pages contributed by the OpenSurgiSim team as part of the Global Surgical Training Challenge.

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