Feasibility of four-dimensional preoperative simulation for elbow debridement arthroplasty

Targeted four-dimensional computerized tomography scans for elbow disorders: a literature review and refinement of existing technique with two exemplar cases

Background

Four-dimensional computerized tomographies (4D-CTs) or motion CTs in elbow disorders have several potential advantages over conventional static imaging such as a reduction of misdiagnoses, a more targeted surgical approach, better patient understanding of their condition and potentially faster operative times. However, the radiation dose is higher than conventional static CT scans so this should be used judiciously. Our study reviews the current literature for 4D-CTs in dynamic elbow disorders and provides a technical note describing radiation-reduced targeted elbow 4D-CTs (te4D-CT) with two exemplar cases alongside our recommendations for when te4D-CTs are indicated.

Methods

te4D-CTs are performed in a lateral decubitus elbow above head position. Preliminary static source axial cut CT obtained with subsequent sagittal and axial planes reconstruction and 3D reconstruction obtained, followed by scan performed in motion and reconstructed to 4D Component. te4D-CTs are taken for either flexion and extension (FE) or pronation and supination (PS) motions depending on the clinical pathology suspected following thorough clinical examination.

Results

te4D-CT for PS and FE protocol scans had an effective radiation exposure dose of 0.53 and 0.95mSv, respectively, compared to 1.13-1.83 mSv in conventional elbow 4D-CTs. In addition, te4D-CTs have good diagnostic accuracy provided that the FE or PS pathology is identified carefully by the ordering physician.

Conclusion

te4D-CT using isolated pronation and supination, or flexion and extension protocols does come with a significantly reduced radiation dose and can be of equal clinical yield compared with 4D-CTs.

Four-dimensional computed tomography scan for dynamic elbow disorders: recommendations for clinical utility

BACKGROUND

Four-dimensional computed tomography (4D CT) is rapidly emerging as a diagnostic tool for the investigation of dynamic upper limb disorders. Dynamic elbow pathologies are challenging to diagnose, and at present, limitations exist in current imaging modalities.

OBJECTIVE

We aimed to assess the clinical utility of 4D CT in detecting potential dynamic elbow disorders.

METHODS

Twenty-eight elbow joints from 26 patients with symptoms of dynamic elbow pathology were included in this study. They were first assessed by a senior orthopedic surgeon with subsequent qualitative data obtained via a Siemens Force Dual Source CT scanner (Erlangen, Germany), producing two- and three-dimensional "static" images and 4D dynamic "movie" images for assessment in each clinical scenario. Clinical assessment before and after scan was compared.

RESULTS

Use of 4D CT scan resulted in a change of diagnosis in 16 cases (57.14%). This included a change in primary diagnosis in 2 cases (7.14%) and secondary diagnosis in 14 cases (50%). In 25 cases (89.29%), the 4D CT scan allowed us to understand the pathological anatomy in greater detail which led to a change in the management plan of 15 cases (53.57%).

CONCLUSION

4D CT is a promising diagnostic tool in the management of dynamic elbow disorders and may be considered in clinical practice. Future studies need to compare it with other diagnostic modalities such as three-dimensional CT.

Experimental pilot study for augmented reality-enhanced elbow arthroscopy

The purpose of this study was to develop and evaluate a novel elbow arthroscopy system with superimposed bone and nerve visualization using preoperative computed tomography (CT) and magnetic resonance imaging (MRI) data. We obtained bone and nerve segmentation data by CT and MRI, respectively, of the elbow of a healthy human volunteer and cadaveric Japanese monkey. A life size 3-dimensional (3D) model of human organs and frame was constructed using a stereo-lithographic 3D printer. Elbow arthroscopy was performed using the elbow of a cadaveric Japanese monkey. The augmented reality (AR) range of error during rotation of arthroscopy was examined at 20 mm scope-object distances. We successfully performed AR arthroscopy using the life-size 3D elbow model and the elbow of the cadaveric Japanese monkey by making anteromedial and posterior portals. The target registration error was 1.63 ± 0.49 mm (range 1-2.7 mm) with respect to the rotation angle of the lens cylinder from 40° to - 40°. We attained reasonable accuracy and demonstrated the operation of the designed system. Given the multiple applications of AR-enhanced arthroscopic visualization, it has the potential to be a next-generation technology for arthroscopy. This technique will contribute to the reduction of serious complications associated with elbow arthroscopy.

The clinical impact of arthroscopic vs. open osteocapsular débridement for primary osteoarthritis of the elbow: a systematic review

BACKGROUND

Primary elbow osteoarthritis (PEOA) is a debilitating disease that can be difficult to treat. Osteocapsular débridement (OD) has been described through various approaches, including arthroscopic and open approaches, with successful outcomes in treating PEOA. There is insufficient evidence in the literature to date to demonstrate the superiority of any approach. The purpose of this review was to compare the clinical results of arthroscopic vs. open OD for PEOA.

METHODS

The online databases PubMed, Embase (Elsevier), and Scopus (Elsevier) were searched from inception through April 1, 2018, for clinical studies reporting on OD. Studies were stratified based on an arthroscopic vs. open approach. Weighted means were calculated for surgical and patient-reported outcomes.

RESULTS

We included 30 studies, reporting on 871 patients and 887 elbows, with a mean follow-up period of 44.3 ± 25.5 months. Of these studies, 15 (420 elbows) reported on open OD, 14 (456 elbows) reported arthroscopic OD, and 1 reported on a cohort of each approach (open in 5 elbows and arthroscopic in 6). The Mayo Elbow Performance Score improved by 28.6 ± 4.57 in the open group vs. 26.6 ± 7.24 in the arthroscopic group. Flexion improved by 19° ± 6° in the open group and 10° ± 6° in the arthroscopic group. Extension improved by 11° ± 5° in the open group and 11° ± 6° in the arthroscopic group.

CONCLUSIONS

Open OD and arthroscopic OD are effective surgical treatment options for patients with symptomatic PEOA, reliably improving flexion, extension, and functional outcome scores with low complication rates.

Validation of the registration accuracy of navigation-assisted arthroscopic débridement for elbow osteoarthritis

BACKGROUND

The identification and precise removal of bony impingement lesions during arthroscopic débridement arthroplasty for elbow osteoarthritis is technically difficult. Surgical navigation systems, combined with preoperative 3-dimensional (3D) assessment of bony impingements, can provide real-time tracking of the surgical instruments and impingement lesions. This study aims to determine the registration accuracy of the navigation system for the humerus and ulna during elbow arthroscopy.

METHODS

We tested the registration procedure using resin bone models of 3 actual patients with elbow osteoarthritis. We digitized bone surface points using navigation pointers under arthroscopy. We initially performed paired-point registration, digitizing 6 preset anatomical landmarks, and then refined the initial alignment with surface matching registration, digitizing 30 points. The registration accuracy for each trial was evaluated as the mean target registration error in each reference marker. Three observers repeated the registration procedure 5 times each with the 3 specimens (total, 45 trials). The median of the registration accuracy was evaluated in total (45 trials) as the accuracy of the registration procedure. The differences in the registration accuracy among the 3 observers (median of 15 trials) were also examined.

RESULTS

The total registration accuracies were 0.96 mm for the humerus and 0.85 mm for the ulna. No significant differences were found in the registration accuracy for the humerus and ulna among the 3 observers.

CONCLUSIONS

This arthroscopic-assisted registration procedure is sufficiently feasible and accurate for application of the navigation system to arthroscopic débridement arthroplasty in clinical settings.

Can preoperative imaging predict the outcomes after arthroscopic release for elbow arthritis?

INTRODUCTION

The primary symptoms of elbow osteoarthritis are the progressive development of stiffness along with pain at the end range of motion due to osteophyte impingement. Surgical treatment involves resecting these "bone stops". In the literature, these osteophytic lesions are more common than cartilage lesions, which suggests they may occur beforehand. The aim of our study was to confirm osteophytes are more common than cartilage lesions, and also to establish a link between these lesions and the functional outcomes.

METHODS

This was a prospective multicenter (8 hospitals) study conducted in the context of a symposium of the Francophone Arthroscopy Society (SFA). Eighty-seven patients with elbow osteoarthritis treated by arthroscopic release were included. The clinical outcomes (range of motion in flexion, extension and pronation-supination; strength; pain at rest and during activity; satisfaction; Andrews and Carson score; QuickDASH, Patient-Rated Elbow Evaluation (PREE), Mayo Elbow Performance Score (MEPS), Self-Evaluation Elbow (SEE) were determined before the procedure and at the 6-month follow-up visit. A standard radiographic assessment was done before the surgery and at the last follow-up visit. A CT arthrogram was done before the procedure. The presence of joint narrowing, osteophytes, filling of fossa along with secondary osteochondroma was evaluated in terms of their location, severity, size and/or number. The presence of radial head subluxation was recorded. The Bröberg & Morrey and Rettig & Hastings classification systems were applied. All the postoperative clinical data along with their change (difference between preoperative and postoperative values) were compared to the imaging findings.

RESULTS

Osteophytes were found in 95% of our patients. They were located at the olecranon in 85% of cases and at the coronoid process in 81%. Filled fossae found in 94% of cases. The olecranon, coronoid and radial fossa were filled in 83%, 80% and 60% of elbows, respectively. On the initial X-rays, joint narrowing was found in 68% of elbows. CT arthrogram identified narrowing in 70% of cases. Narrowing was present in the humeroradial joint in 60% of cases and in the humeroulnar joint in 23% of cases. The presence of joint narrowing on CT arthrogram was a negative prognostic factor for pain during activity (p<0.05) along with the Quick DASH (p<0.01) and PREE (p<0.05). Involvement of the humeroradial joint impacted pain at rest (p<0.01). Narrowing of the humeroulnar joint was associated with worse outcomes in terms of pain at rest (p<0.05) and during activity (p<0.05), QuickDASH (p<0.005), MEPS (p<0.05), PREE (p<0.05) and the SEE (p<0.05). The presence of loose bodies before the procedure was associated with better outcomes in terms of pain at rest (p<0.05), QuickDASH (p<0.001), MEPS (p<0.001), Andrews & Carson score (p<0.05) and PREE (p<0.005). The osteoarthritis stage in the Bröberg & Morrey or the Rettig & Hastings classification systems did not impact the various clinical parameters or functional outcome scores.

DISCUSSION/CONCLUSION

In the imaging work-up, signs of impingement (osteophytes and filling of fossa) are more common than signs of joint narrowing. The presence of humeroulnar and/or humeroradial impingement when there are no cartilage lesions visible may correspond to a pre-arthritic stage. The outcomes of arthroscopic release are better in elbows with isolated impingement than in those with cartilage lesions, especially at the humeroulnar joint. Excision of secondary osteochondromas is also an excellent surgical indication. Current classification systems cannot be used to determine the prognosis before arthroscopic release of elbow osteoarthritis cases.

LEVEL OF EVIDENCE

III, Prospective multicenter observational cohort study.

Tibiofibular syndesmosis in asymptomatic ankles: initial kinematic analysis using four-dimensional CT

AIM

To evaluate the reliability of ankle syndesmotic measurements and their changes during active motion using four-dimensional computed tomography (4DCT) examination in asymptomatic ankles.

MATERIALS AND METHODS

4DCT was performed on both ankles of patients with signs and symptoms of unilateral ankle instability. Ankles from the asymptomatic side of 10 consecutive patients were included in this analysis. Five ankle syndesmotic measurements were adopted from the available literature and performed by two fellowship-trained foot and ankle surgeons: (1) syndesmotic anterior distance (SAD); (2) syndesmotic posterior distance (SPD); (3) syndesmotic translation (ST); (4) syndesmotic tibiofibular angle (STFA); and (5) ankle tibiofibular angle (ATFA). A Monte Carlo simulation was also performed to obtain exact p-values with 99% confidence intervals.

RESULTS

Excellent interobserver reliability was observed among the two readers for four out of five measurements (intra-class correlation coefficients [ICC]: 0.767-0.995, p<0.001-0.020). The ICC values for SAD were not statistically significant (ICC=0.548 and 0.569 for dorsi and plantarflexion respectively, p=0.1). Among the five measurements, only ST measurements had significant changes during active motion (median [interquartile range] for change: -0.70 mm [-1.6-0.10]; p=0.012). Of the above measurements, only the ST measurements demonstrated a negative linear association with the tibiocalcaneal angle during active motion (beta=-2.5, p=0.04).

CONCLUSIONS

Reliable quantitative kinematic assessment of ankle syndesmosis can be performed using 4DCT examination. Syndesmotic measurements remain unchanged during ankle motion except for the syndesmotic translation, which tends to decrease during plantar flexion.

Diagnosis and Longitudinal Assessment of Osteoarthritis: Review of Available Imaging Techniques

Osteoarthritis (OA) is a major chronic and global health care problem. Recent technological advances in imaging and postprocessing techniques have enhanced the understanding and characterization of the pathophysiology of this chronic and prevalent disease. Although plain radiograph remains the modality of choice for initial assessment of OA, recent studies have shown that advanced cross-sectional imaging can improve the early detection, grading, structural damage quantification, and risk stratification of OA. This article discusses the currently available evidence regarding both the conventional and novel imaging modalities that can be used for evaluation of patients with OA and its longitudinal assessment.