Artificial intelligence powered advancements in upper extremity joint MRI: A review.

Magnetic resonance imaging (MRI) is an indispensable medical imaging examination technique in musculoskeletal medicine. Modern MRI techniques achieve superior high-quality multiplanar imaging of soft tissue and skeletal pathologies without the harmful effects of ionizing radiation. Some current limitations of MRI include long acquisition times, artifacts, and noise. In addition, it is often challenging to distinguish abutting or closely applied soft tissue structures with similar signal characteristics. In the past decade, Artificial Intelligence (AI) has been widely employed in musculoskeletal MRI to help reduce the image acquisition time and improve image quality. Apart from being able to reduce medical costs, AI can assist clinicians in diagnosing diseases more accurately. This will effectively help formulate appropriate treatment plans and ultimately improve patient care. This review article intends to summarize AI's current research and application in musculoskeletal MRI, particularly the advancement of DL in identifying the structure and lesions of upper extremity joints in MRI images.

Arthroscopic Bone Grafting and Robot-assisted Fixation for Scaphoid Nonunion.

OBJECTIVES: Scaphoid nonunion remains a challenging problem to manage with no general consensus on its treatment recommendations. We propose a novel minimally invasive (MIS) technique of arthroscopic bone grafting (ABG) with robot-assisted fixation for the treatment of scaphoid nonunions. METHODS: Patients with radiographically proven scaphoid nonunion treated by this novel surgical technique were included. Following arthroscopic debridement and iliac crest bone grafting, the scaphoid was fixed percutaneously using either multiple Kirschner (K)-wires or a headless compression screw using a robotic navigation system. RESULTS: Six male patients with an average age of 29.2 years were enrolled. Four patients had scaphoid waist fractures, and the other two were proximal pole fractures. During wrist arthroscopy, punctate bleeding of the proximal scaphoid fragment was observed in four out of the six patients. Half of the patients were fixed using a headless compression screw and the other half using multiple K-wires. All the guidewires were placed with a single-attempt using the robotic navigation system. Postoperatively, all the scaphoid fractures had complete radiographic union by 16 weeks. At a mean follow-up of 18.3 months, there were significant improvements in wrist range of motion, grip strength, and patient-rated outcomes. No intraoperative or early postoperative complications were encountered in any of our patients. CONCLUSION: Arthroscopic bone grafting with robot-assisted fixation is a feasible and promising therapeutic option for scaphoid nonunions, regardless of the vascularity of the proximal pole fragment. This novel technique allows for anatomic restoration of the scaphoid alignment and accurate, targeted placement of implants into the scaphoid nonunion site within a single-attempt using a robotic navigation system.

A comparative cadaveric study for percutaneous scaphoid fixation: robotic vs freehand.

PURPOSES: To compare the robotic-assisted and the traditional freehand percutaneous scaphoid fixation in number of guidewire attempts, duration of fluoroscopy time, amount of radiation dose, and screw centrality. METHODS: Twenty cadaveric specimens were randomized into either the robotic or freehand group. The scaphoids in both groups were fixed by either the same attending or resident from our hand surgery department. The operation duration, amount of radiation from intraoperative fluoroscopy, total fluoroscopy time, and the number of guidewire attempts were documented and compared. Postoperatively, all the specimens had a computed tomography (CT) scan performed, and the difference in the final position of the screw and the central axis of the scaphoid was examined. RESULTS: In the robotic group, all the guide wires were satisfactorily positioned within a single attempt, while the median number of attempts in the traditional freehand group was 18 (quaternion 14-65). This also meant that the surgeon in the robotic group experienced significantly lower radiation exposure dose and time as compared to the freehand group. There were no significant differences in the final screw position as compared to the central axis of the scaphoid in both groups. Although there was no difference in surgeon performance in the robotic group, the operative time for the attending was significantly lower as compared to the resident in the freehand group. CONCLUSION: Robotic-assisted surgery for scaphoid fracture fixation is superior to the traditional freehand method as it facilitates accurate screw placement with lower radiation exposure and fewer guide wire attempts.

Locally Invasive Pigmented Villonodular Synovitis of the Wrist Treated by Arthroscopic Resection and Bone Grafting.

Pigmented villonodular synovitis (PVNS) is a benign but locally aggressive neoplasm that can affect tendon sheath, bursae, or joint. The wrist joint however is uncommonly involved and here we present a case of chronic monoarticular joint pain and swelling in a healthcare professional that was later histologically verified to be PVNS of the radiocarpal joint. The patient had a magnetic resonance imaging (MRI) performed prior to surgery which showed a locally invasive bony tumor of the scaphoid. He subsequently underwent a wrist arthroscopic evaluation and resection with bone grafting as the index surgery and made an uneventful postoperative recovery. This is a novel technique to address PVNS of the wrist as these cases are usually managed using open procedures which can lead to additional scarring and disrupt the blood supply of the joint capsule.

A Novel Technique of Arthroscopic-Assisted Four-Corner Fusion and Robot-Assisted Fixation for Scaphoid Nonunion Advanced Collapse Wrist: A Single Case Study.

OBJECTIVE: Scaphoid nonunion advanced collapse (SNAC) is a relatively common and debilitating wrist disorder yet its treatment remains challenging and controversial. We aim to describe a novel technique of a dual arthroscopic and robotic assisted four-corner fusion (4CF) in the treatment of SNAC wrist. METHODS: In this study, we describe an original arthroscopic and robotic assisted 4CF, which is novel and currently unpublished in literature. The surgical approach included these predefined steps: arthroscopic resection of the scaphoid, radial styloid and of diseased cartilage between the capitate-lunate joint and triquetrum-hamate joint, correction of Dorsal Intercalated Segment Instability (DISI) deformity of the wrist and robotic assisted 4CF performed percutaneously with screws. Dynamic fluoroscopic imaging with the mini C-arm was performed five times and the 3D scanning machine was used once. RESULTS: Our patient with SNAC II wrist was 57 years old at the time of initial presentation with a history of untreated traumatic wrist injury approximately 20 years ago. Regular wrist X-rays were performed at the outpatient setting and a computed tomography (CT) of the wrist was performed at the third postoperative month to confirm bony union. The patient's wrist range of motion (ROM), grip strength, Visual Analog Scale (VAS) score, Quick Disabilities of Arm, Shoulder, and Hand (QuickDASH) score, Modified Mayo Wrist Score (MMWS), and Patient Rated Wrist Evaluation (PRWE) were also evaluated during short-term follow-up at 6 months. During the patient's review at 6 months, his VAS score was 0 with complete pain relief. His wrist flexion was 20° and wrist extension at 45°. His pronation-supination was normal and comparable to his uninjured contralateral wrist. His operated wrist which was also his dominant hand had a grip strength of 22 kg as compared with 28 kg of the unaffected hand. He also had a Mayo Wrist Score of 85, QuickDASH score of 2.3 and PRWE of 6, and resumed his occupation as a clerk at 3 months. CONCLUSIONS: This dual arthroscopic and robotic assisted 4CF is a novel surgical method worth considering in the treatment of SNAC II wrists. It is minimally invasive and allows for accurate placement of the screws in a single attempt. There was bony union by the third postoperative month as confirmed by CT imaging and excellent resolution of symptoms.

Surgical Management of Peripheral Vein Thrombophlebitis in the Upper Extremity.

Purpose: Peripheral vein thrombophlebitis has a reported overall incidence ranging from 20% to 80%. Thrombophlebitis can progress despite antibiotic therapy to become a challenging clinical problem requiring surgical intervention. There is currently no consensus on its optimal management. We reviewed our experience of surgical intervention with analyses of the indications for intervention, descriptions of the surgical procedures, and outcomes. We aimed to provide guidance on the management of this potentially serious complication. Methods: This is a retrospective review of 51 patients with thrombophlebitis refractory to conservative management between January 2017 and August 2020. Results: Analyses revealed a high prevalence of comorbidities, including diabetes mellitus, malignancy, and chronic kidney disease. A total of 60% of patients had concurrent bacteremia, and the decision to operate had a low threshold in the presence of these factors. On exploration, 80% of patients had intraluminal thrombus, 47% had intraluminal pus, and 29% had pus beyond the veins or extending proximally. The surgical approach employed in 98% of patients involved an extensile incision in those with several morbidity factors (diabetes mellitus, chronic kidney disease, or bacteremia). One patient presented with severe clinical signs of local infection, and on exploration, there was intraluminal pus and thrombus up to 10 cm. A novel technique of a minimally invasive approach of intermittent stab incisions was employed in a young and healthy patient without comorbidities. Conclusions: We developed an algorithm to guide the indications for intervention and surgical approach to thrombophlebitis. The threshold for intervening surgically should be lowered by the presence of comorbidities. The failure of antibiotics to resolve the clinical signs of infection or the suspicion of abscess formation should mandate intervention. Thrombosed sections of the vein should be ligated proximally and distally and excised and surrounding collections of pus drained. Delayed secondary wound closure is usual. Stab incisions may limit surgical dissection and subsequent scarring in less severe cases. Type of study/level of evidence: Prognostic IV.

A Biomechanical Comparison of Gliding Resistance between Modified Lim Tsai and Asymmetric Tendon Repair Techniques in Zone II Flexor Tendon Repairs.

Background: Early active motion protocols have shown better functional outcomes in zone II flexor tendon lacerations. Different techniques of tendon repair have different effects on gliding resistance, which can impact tendon excursion and adhesion formation. For successful initiation of early active mobilisation, the repair technique should have high breaking strength and low gliding resistance. Previous studies have shown the Modified Lim-Tsai technique demonstrates these characteristics. The Asymmetric repair has also shown superior ultimate tensile strength. This study aims to compare the gliding resistance between the two techniques. Methods: FDP tendons from ten fresh frozen cadaveric fingers were randomly divided into two groups, transected completely distal to the sheath of the A2 pulley and repaired using either the Modified Lim-Tsai or Asymmetric technique. The core repair was performed with Supramid 4-0 looped sutures and circumferential epitendinous sutures were done with nylon monofilament Prolene 6-0 sutures. The gliding resistance and ultimate tensile strength were then tested. Results: The gliding resistance of the Asymmetric and Modified Lim-Tsai repair techniques were 0.2 and 0.95 N respectively. This difference was significant (p = 0.008). The Modified Lim-Tsai technique had a higher ultimate tensile strength and load to 2 mm gap formation, though this was not significant. Conclusions: Gliding resistance of the Asymmetric repair is significantly less than that of Modified Lim-Tsai. Ultimate tensile strength and load to 2 mm gap formation are comparable.

Biomechanical Study of Asymmetric Flexor Tendon Repair Using 3 Different Suture Materials.

Background: The asymmetric technique for flexor tendon repairs has various advantages but further improvement is possible by using a suitable suture material. In this study, we compare the biomechanical performance of asymmetric repairs using 3 suture materials: Supramid Extra II 4-0, Tendo-Loop 4-0, and FiberLoop 4-0. Methods: We divided 30 porcine flexor tendons into 3 arms. Each arm of tendons were repaired by using 1 of the 3 proposed suture materials. Each repaired tendon was tested by using a mechanical tester. Ultimate tensile strength (UTS), load to 2 mm gap force, failure mechanism and stiffness of the tendons were investigated. Results: FiberLoop® achieved the highest UTS (90.4 ± 17.9 N), followed by Tendo-Loop (85.3 ± 10.3 N). The difference was no statistically significant. The UTS of repairs using Supramid® was significantly lower (64.0 ± 8.4 N). For load to 2 mm gap force, FiberLoop® achieved 20.7 ± 4.8 N while Tendo-Loop® had 20.5 ± 4.2 N. The difference was also no statistically significant. The repairs using Supramid® had a significantly lower load to 2 mm gap force of 14.2 ± 2.7 N. The stiffness of asymmetric repairs using FiberLoop® and Tendo-Loop® was 5.64 ± 1.7 N/mm and 5.63 ± 0.7 N/mm. The difference was also no statistically significant. The repairs using Supramid® had a significantly lower stiffness of 4.15 ± 1.0 N/mm. Failure mechanisms for the repaired specimens were reported as such: Supramid had 100% suture rupture; Tendo-Loop had 90% suture rupture and 10% suture pullout; FiberLoop had 20% suture rupture and 80% suture pullout. Conclusions: The asymmetric repair configuration is able to produce superior biomechanical performance by using Tendo-Loop® or FiberLoop®. Improvement of the asymmetric technique by using Tendo-Loop® or FiberLoop® could potentially contribute to better surgical outcomes of flexor tendon repair.

Elbow Flexion Reconstruction in Brachial Plexus Avulsion Injuries - Results with Intercostal Nerve and Distal Nerve Transfers.

Background: The neural surgical options for reconstruction of elbow flexion in brachial plexus injuries depend on the availability of nerve donors. In upper-type avulsion injuries, the ulnar or median nerves, when intact, are reliable intra-plexal donor nerves for transfers to the biceps muscle. In complete avulsion injuries, donors are limited to extra-plexal sources, such as intercostal nerves (ICNs). Methods: We reviewed our results of ICN and partial distal nerve (ulnar or median) transfers for elbow flexion reconstruction in patients with brachial plexus avulsion injuries. The time taken for recovery of elbow flexion strength to M3 and the final motor outcome at 2 years were compared between both groups. Results: 38 patients were included in this study. 27 had ICN transfers to the musculocutaneous nerve (MCN), 8 had partial ulnar nerve transfers and 3 had partial median nerve transfers to the MCN's biceps motor branch. The mean time interval from injury to surgery was 3.6 months. Recovery of elbow flexion was observed earlier in the distal nerve transfer group (p < 0.05). Overall, success rates were higher in patients with distal nerve transfers (100%), compared to ICN transfers (63%) at 2 years (p = 0.018). Patients with distal nerve transfers achieved a higher final median strength of M4.0 [Interquartile range (IQR) 3.5-4.5], compared to M3.5 (IQR 2.0-4.0) in the ICN group (p = 0.031). In the subgroup of patients with upper-type brachial plexus injuries, there were no significant differences in motor outcomes between the ICN versus distal nerve transfers group. Conclusions: In our entire cohort, patients with distal nerve transfers had faster motor recovery and better elbow flexion power than patients with ICN transfers. In patients with partial brachial plexus injuries, outcomes of ICN transfers were not inferior to distal nerve transfers.

Cyclic Testing of the 6-Strand Tang and Modified Lim-Tsai Flexor Tendon Repair Techniques.

PURPOSE: In this study, we compared the Tang repair technique with the 6-strand modified Lim-Tsai repair technique under cyclic testing conditions. METHODS: Twenty fresh-frozen porcine flexor tendons were randomized into 2 groups for repair with either the modified Lim-Tsai or the Tang technique using Supramid 4-0 core sutures and Ethilon 6-0 epitendinous running suture. The repaired tendons were subjected to 2 stage cyclic loading. The survival rate and gap formation at the repair site were recorded. RESULTS: Tendons repaired by the Tang technique achieved an 80% survival rate. None of the modified Lim-Tsai repairs survived. The mean gap formed at the end of 1000 cycles was 1.09 mm in the Tang repairs compared with 4.15 mm in the modified Lim-Tsai repairs. CONCLUSIONS: The Tang repair is biomechanically stronger than the modified Lim-Tsai repair under cyclic loading. CLINICAL RELEVANCE: The Tang repair technique may exhibit a higher tolerance for active mobilization after surgery with less propensity for gap formation.

Clinical Assessment and Diagnostics of Patients With Hand Disorders: A Case Study Approach.

Clinical assessment of the hand is important for diagnosing underlying hand disorders. Using a case study approach, the clinical assessment for three disorders of the hands is presented: trigger finger (stenosing tenosynovitis), carpal tunnel syndrome, and ulnar-sided wrist injury (styloid impingement). We assess the annular one pulley and finger range of motion for patients with trigger finger. To diagnose for carpal tunnel syndrome, assessment for Tinel's sign, Phalen's sign, abductor pollicis brevis muscle bulk, two-point discrimination, and obtaining a nerve conduction study are performed. Assessment for ulnar-sided wrist injury includes wrist range of motion, assessment of distal radial ulnar joint stability, provocation tests, grip strength, x-ray, and magnetic resonance imaging. This article begins with a description of the hand and wrist anatomy. For each case study, the clinical history is described, followed by a discussion of the pathophysiology, clinical assessments, and diagnostic tests.