Computer-assisted preoperative planning for proximal humeral fractures by minimally invasive plate osteosynthesis:

Preoperative templating in orthopaedic fracture surgery: The past, present and future

Preoperative planning in orthopaedic fracture surgery corroborates with the goal of establishing the best possible surgical result and ensuring a functioning limb for the patient. From placing sketches on overhead projector paper and measuring lengths from anatomical landmarks, ways of preoperative planning have evolved rapidly over the last 100 years. Today, preoperative planning includes methods such as advanced 3-Dimensional (3D) printed models and software programs incorporating entire libraries of osteosynthesis materials that can be shaped and rotated to fit a patient's specific anatomy. Relevant literature was evaluated to review the development of preoperative templating from the past and present, in order to assess its impact on the future of osteosynthesis.We identified studies on 3D-imaging, computer-assisted systems, and 3D-printed fractured bones and drill guides. The use of some of these systems resulted in a reduction in operation time, blood loss, perioperative fluoroscopy and hospital stay, as well as better placement of osteosynthesis material. Only few studies have identified differences in patient morbidity and mortality. Future techniques of preoperative templating are on the rise and the potential is vast. The cost-effectiveness and usefulness of certain methods need to be evaluated further, but the benefit of preoperative templating has the potential of being revolutionary, with the possibility of radical advances within orthopaedic surgery.

Computer-assisted preoperative planning of bone fracture fixation surgery: A state-of-the-art review

Background: Bone fracture fixation surgery is one of the most commonly performed surgical procedures in the orthopedic field. However, fracture healing complications occur frequently, and the choice of the most optimal surgical approach often remains challenging. In the last years, computational tools have been developed with the aim to assist preoperative planning procedures of bone fracture fixation surgery.

Objectives: The aims of this review are 1) to provide a comprehensive overview of the state-of-the-art in computer-assisted preoperative planning of bone fracture fixation surgery, 2) to assess the clinical feasibility of the existing virtual planning approaches, and 3) to assess their clinical efficacy in terms of clinical outcomes as compared to conventional planning methods.

Methods: A literature search was performed in the MEDLINE-PubMed, Ovid-EMBASE, Ovid-EMCARE, Web of Science, and Cochrane libraries to identify articles reporting on the clinical use of computer-assisted preoperative planning of bone fracture fixation.

Results: 79 articles were included to provide an overview of the state-of-the art in virtual planning. While patient-specific geometrical model construction, virtual bone fracture reduction, and virtual fixation planning are routinely applied in virtual planning, biomechanical analysis is rarely included in the planning framework. 21 of the included studies were used to assess the feasibility and efficacy of computer-assisted planning methods. The reported total mean planning duration ranged from 22 to 258 min in different studies. Computer-assisted planning resulted in reduced operation time (Standardized Mean Difference (SMD): -2.19; 95% Confidence Interval (CI): -2.87, -1.50), less blood loss (SMD: -1.99; 95% CI: -2.75, -1.24), decreased frequency of fluoroscopy (SMD: -2.18; 95% CI: -2.74, -1.61), shortened fracture healing times (SMD: -0.51; 95% CI: -0.97, -0.05) and less postoperative complications (Risk Ratio (RR): 0.64, 95% CI: 0.46, 0.90). No significant differences were found in hospitalization duration. Some studies reported improvements in reduction quality and functional outcomes but these results were not pooled for meta-analysis, since the reported outcome measures were too heterogeneous.

Conclusion: Current computer-assisted planning approaches are feasible to be used in clinical practice and have been shown to improve clinical outcomes. Including biomechanical analysis into the framework has the potential to further improve clinical outcome.

Computer-assisted preoperative planning of reduction of and osteosynthesis of scapular fracture: A case report

Introduction

Reports on the use of computer-assisted trauma surgery of comminuted scapula fracture are still quite rare. In this article, we present a case of comminuted scapula fracture, the surgical reconstruction of which was pre-operatively planned using a complex software solution.

Materials and methods

For surgical planning of the fracture, we used the TraumaTech software facilitating virtual reconstruction (both manual and automatic), surgery planning, design of the implant, planning of screw placement and lengths, and production of a 3D print model of the fracture and the implant. The software also supported ordering such custom-made plate from a plate producer who was capable of fast and precise production of the plate.

Results

The surgery using the custom-ordered plate was successful. The actual used screw lengths did not differ from the planned ones by more than 2 mm. One year after the surgery, the patient was capable of more demanding activities and doing sports activities.

Conclusion

This approach provides a great way to prevent complications of the surgery and to shorten its duration. To the best of our knowledge, this is the first description of the treatment of a scapula comminuted fracture utilizing computer-assisted preoperative planning.

Advanced CT visualization improves the accuracy of orthopaedic trauma surgeons and residents in classifying proximal humeral fractures: a feasibility study

PURPOSE

Osteosynthesis of proximal humeral fractures remains challenging with high reported failure rates. Understanding the fracture type is mandatory in surgical treatment to achieve an optimal anatomical reduction. Therefore, a better classification ability resulting in improved understanding of the fracture pattern is important for preoperative planning. The purpose was to investigate the feasibility and added value of advanced visualization of segmented 3D computed tomography (CT) images in fracture classification.

METHODS

Seventeen patients treated with either plate-screw-osteosynthesis or shoulder hemi-prosthesis between 2015 and 2019 were included. All preoperative CT scans were segmented to indicate every fracture fragment in a different color. Classification ability was tested in 21 orthopaedic residents and 12 shoulder surgeons. Both groups were asked to classify fractures using three different modalities (standard CT scan, 3D reconstruction model, and 3D segmented model) into three different classification systems (Neer, AO/OTA and LEGO).

RESULTS

All participants were able to classify the fractures more accurately into all three classification systems after evaluating the segmented three-dimensional (3D) models compared to both 2D slice-wise evaluation and 3D reconstruction model. This finding was significant (p < 0.005) with an average success rate of 94%. The participants experienced significantly more difficulties classifying fractures according to the LEGO system than the other two classifications.

CONCLUSION

Segmentation of CT scans added value to the proximal humeral fracture classification, since orthopaedic surgeons were able to classify fractures significantly better into the AO/OTA, Neer, and LEGO classification systems compared to both standard 2D slice-wise evaluation and 3D reconstruction model.

Evaluation of the computer-assisted virtual surgical technology in preoperative planning for distal femoral fracture

BACKGROUND

The application of computer-assisted virtual surgical technology in preoperative planning for distal femoral fractures has been rarely presented. This study aimed to evaluate the intra-operative realization of this technology and the clinical outcomes based on it for distal femoral fractures.

METHODS

Between February 2014 and May 2017, 32 patients with distal femoral fractures treated by open reduction and internal fixation were included and divided into 2 groups on the basis of preoperative planning methods: conventional (N = 17) and virtual surgical (N = 15). The time required for virtual segmentation, reduction, and fixation of the fracture fragments in virtual surgical group were analyzed. Operation time, intra-operative blood loss, times of fluoroscopy during operation and days of hospital stay in two groups were compared. Postoperative functional outcomes were assessed using the Knee Society Score (KSS), Short Form-36 (SF-36) scoring systems, and visual analogue scale (VAS) for pain.

RESULTS

Mean total planning time for 33-A, 33-B, and 33-C fractures in virtual surgical group were 43.0 ± 1.7, 23.0 ± 1.3, and 51.4 ± 3.7 min, respectively. Compared with the conventional group, Patients in virtual surgical group had lower blood loss, fewer fluoroscopic images, less operative time, and shorter days of hospital stay (P < 0.05). No significant difference could detected in the KSS, SF-36, or VAS scores between the two groups at the final follow-up (P > 0.05).

CONCLUSIONS

Computer-assisted virtual surgical technology could rapidly complete surgical treatment protocol, improve operative efficiency, and provide satisfying clinical and radiographic outcomes for distal femoral fractures.

Influence of Medial Support Screws on the Maintenance of Fracture Reduction after Locked Plating of Proximal Humerus Fractures

Background

Technical aspects of the correct placement of medial support locking screws in the locking plate for proximal humerus fractures remain incompletely understood. This study was to evaluate the clinical relationship between the number of medial support screws and the maintenance of fracture reduction after locked plating of proximal humerus fractures.

Methods

We retrospectively evaluated 181 patients who had been surgically treated for proximal humeral fractures (PHFs) with a locking plate between September 2007 and June 2013. All cases were then subdivided into one of four groups as follows: 75 patients in the medial cortical support (MCS) group, 26 patients in the medial multiscrew support (MMSS) group, 29 patients in the medial single screw support (MSSS) group, and 51 patients in the no medial support (NMS) group. Clinical and radiographic evaluations included the Constant-Murley score (CM), visual analogue scale (VAS), complications, and revision surgeries. The neck-shaft angle (NSA) was measured in a true anteroposterior radiograph immediately postoperation and at final follow-up. One-way analysis of variance or Kruskal-Wallis test was used for statistical analysis of measurement data, and Chi-square test or Fisher's exact test was used for categorical data.

Results

The mean postoperative NSAs were 133.46° ± 6.01°, 132.39° ± 7.77°, 135.17° ± 10.15°, and 132.41° ± 7.16° in the MCS, MMSS, MSSS, and NMS groups, respectively, and no significant differences were found (F = 1.02, P = 0.387). In the final follow-up, the NSAs were 132.79° ± 6.02°, 130.19° ± 9.25°, 131.28° ± 12.85°, and 127.35° ± 8.50° in the MCS, MMSS, MSSS, and NMS groups, respectively (F = 4.40, P = 0.008). There were marked differences in the NSA at the final follow-up between the MCS and NMS groups (P = 0.004). The median (interquartile range [IQR]) NSA losses were 0.0° (0.0-1.0)°, 1.3° (0.0-3.1)°, 1.5° (1.0-5.2)°, and 4.0° (1.2-7.1)° in the MCS, MMSS, MSSS, and NMS groups, respectively (H = 60.66, P < 0.001). There were marked differences in NSA loss between the MCS and the other three groups (MCS vs. MMSS, Z = 3.16, P = 0.002; MCS vs. MSSS, Z = 4.78, P < 0.001; and MCS vs. NMS, Z = 7.34, P < 0.001). There was also significantly less NSA loss observed in the MMSS group compared to the NMS group (Z = -3.16, P = 0.002). However, there were no significant differences between the MMSS and MSSS groups (Z = -1.65, P = 0.225) or the MSSS and NMS groups (Z = -1.21, P = 0.099). The average CM scores were 81.35 ± 9.79, 78.04 ± 8.97, 72.76 ± 10.98, and 67.33 ± 12.31 points in the MCS, MMSS, MSSS, and NMS groups, respectively (F = 18.68, P < 0.001). The rates of excellent and good CM scores were 86.67%, 80.77%, 65.52%, and 43.14% in the MCS, MMSS, MSSS, and NMS groups, respectively (χ² = 29.25, P < 0.001). The median (IQR) VAS scores were 1 (0-2), 1 (0-2), 2 (1-3), and 3 (1-5) points in the MCS, MMSS, MSSS, and NMS groups, respectively (H = 27.80, P < 0.001). Functional recovery was markedly better and VAS values were lower in the MCS and MMSS groups (for CM scores: MCS vs. MSSS, P < 0.001; MCS vs. NMS, P < 0.001; MMSS vs. MSSS, P = 0.031; and MMSS vs. NMS, P < 0.001 and for VAS values: MCS vs. MSSS, Z = 3.31, P = 0.001; MCS vs. NMS, Z = 4.64, P < 0.001; MMSS vs. MSSS, Z = -2.09, P = 0.037; and MMSS vs. NMS, Z = -3.16, P = 0.003).

Conclusions

Medial support screws might help enhance mechanical stability and maintain fracture reduction when used to treat PHFs with medial metaphyseal comminution or malreduction.

Evaluation of computed tomography post-processing images in postoperative assessment of Lisfranc injuries compared with plain radiographs

Background

The objective of this study is to evaluate the value of computed tomography (CT) post-processing images in postoperative assessment of Lisfranc injuries compared with plain radiographs.

Methods

A total of 79 cases with closed Lisfranc injuries that were treated with conventional open reduction and internal fixation from January 2010 to June 2016 were analyzed. Postoperative assessment was performed by two independent orthopedic surgeons with both plain radiographs and CT post-processing images. Inter- and intra-observer agreement were analyzed by kappa statistics while the differences between the two postoperative imaging assessments were assessed using the χ² test (McNemar’s test). Significance was assumed when p < 0.05.

Results

Inter- and intra-observer agreement of CT post-processing images was much higher than that of plain radiographs. Non-anatomic reduction was more easily identified in patients with injuries of Myerson classifications A, B1, B2, and C1 using CT post-processing images with overall groups (p < 0.05), and poor internal fixation was also more easily detected in patients with injuries of Myerson classifications A, B1, B2, and C2 using CT post-processing images with overall groups (p < 0.05).

Conclusions

CT post-processing images can be more reliable than plain radiographs in the postoperative assessment of reduction and implant placement for Lisfranc injuries.

Postoperative Evaluation of Reduction Loss in Proximal Humeral Fractures: A Comparison of Plain Radiographs and Computed Tomography

OBJECTIVE

To compare postoperative CT images with plain radiographs for measuring prognostic factors of reduction loss of fractures of the proximal part of the humerus.

METHODS

A total of 65 patients who sustained fractures of the proximal humerus treated with locking plates from June 2012 to October 2015 were retrospectively analyzed. There were 24 men and 41 women, with a mean age of 60.0 years (range, 22-76 years). According to the Neer classification system of proximal humeral fracture, there were 26 two-part, 27 three-part and 12 four-part fractures of the proximal part of the humerus, and all fractures were treated with open reduction and internal fixation (ORIF) using locked plating. All postoperative CT images and plain radiographs of the patients were obtained. Prognostic factors of the reduction loss were the change of neck shaft angle (NSA) and the change of humeral head height (HHH). The change of NSA and HHH were evaluated by the difference between postoperative initial and final follow-up measurement. Reduction loss was defined as the change ≥10° for NSA or ≥5 mm for HHH. The NSA and HHH were measured using plain radiographs and 3-D CT images, both initially and at final follow-up. The paired t-test was used for comparison of NSA, change of NSA, HHH, and change of HHH between two image modalities. The differences between two image modalities in the assessment of reduction loss were examined using the χ² -test (McNemar test). Intraclass correlation coefficients (ICC) were used to assess the intra-observer and inter-observer reliability.

RESULTS

3-D CT images (ICC range, 0.834-0.967) were more reliable in all parameters when compared with plain radiographs (ICC range, 0.598-0.915). Significant differences were found between the two image modalities in all parameters (plain radiographs: initial NSA = 133.6° ± 3.8°, final NSA = 130.0° ± 1.9°, initial HHH = 17.9 ± 0.9 mm, final HHH = 15.8 ± 1.5 mm; 3-D CT: initial NSA = 131.4° ± 3.4°, final NSA = 128.8° ± 1.7°, initial HHH = 16.8 ± 1.2 mm, final HHH = 14.5 ± 1.1 mm; all P < 0.05). In the assessment of reduction loss, the percentage was 16.9% (11/65) for the plain radiographs and 7.7% (5/65) for the 3-D CT scans (P < 0.05). For the 5 patients with reduction loss, which were observed by two imaging modalities, the mean Constant-Murley score was 61.0 ± 1.6. The patients with reduction loss, observed only in plain radiographs but not CT images, had good shoulder function (Constant-Murley score: 82.7 ± 1.0).

CONCLUSIONS

Our data reveal that 3-D CT images are more reliable than plain radiographs in the assessment of the prognostic factors of reduction loss of fractures of the proximal part of the humerus with treatment of locking plates; this reliable CT technique can serve as an effective guideline for the subsequent clinical management of patients.

Statistical, Morphometric, Anatomical Shape Model (Atlas) of Calcaneus

The aim was to develop a morphometric and anatomically accurate atlas (statistical shape model) of calcaneus. The model is based on 18 left foot and 18 right foot computed tomography studies of 28 male individuals aged from 17 to 62 years, with no known foot pathology. A procedure for automatic atlas included extraction and identification of common features, averaging feature position, obtaining mean geometry, mathematical shape description and variability analysis. Expert manual assistance was included for the model to fulfil the accuracy sought by medical professionals. The proposed for the first time statistical shape model of the calcaneus could be of value in many orthopaedic applications including providing support in diagnosing pathological lesions, pre-operative planning, classification and treatment of calcaneus fractures as well as for the development of future implant procedures.