Ensemble detection of hand joint ankylosis and subluxation in radiographic images using deep neural networks.

The modified total Sharp score (mTSS) is often used as an evaluation index for joint destruction caused by rheumatoid arthritis. In this study, special findings (ankylosis, subluxation, and dislocation) are detected to estimate the efficacy of mTSS by using deep neural networks (DNNs). The proposed method detects and classifies finger joint regions using an ensemble mechanism. This integrates multiple DNN detection models, specifically single shot multibox detectors, using different training data for each special finding. For the learning phase, we prepared a total of 260 hand X-ray images, in which proximal interphalangeal (PIP) and metacarpophalangeal (MP) joints were annotated with mTSS by skilled rheumatologists and radiologists. We evaluated our model using five-fold cross-validation. The proposed model produced a higher detection accuracy, recall, precision, specificity, F-value, and intersection over union than individual detection models for both ankylosis and subluxation detection, with a detection rate above 99.8% for the MP and PIP joint regions. Our future research will aim at the development of an automatic diagnosis system that uses the proposed mTSS model to estimate the erosion and joint space narrowing score.

Arthrodesis of distal interphalangeal and thumb interphalangeal joint: a retrospective cohort study of 149 cases.

BACKGROUND: Arthrodesis of finger joints is often the last line of treatment of severe pain due to osteoarthritis, rheumatoid arthritis, or mallet finger. At the Department of Orthopedic and Hand Surgery, Örebro University Hospital (ÖUH) in Sweden, the Kirschner-wire technique was standard until 2020, when the headless compression screw technique was introduced as a complement. There is no consensus on which method is superior. The purpose of this study was to examine the outcomes and complications associated with distal interphalangeal (DIP) joint and thumb interphalangeal (IP) joint arthrodesis, and to see whether these correlated with patient-dependent and treatment-related factors. METHODS: In a retrospective cohort study, we evaluated a total of 149 consecutive arthrodeses (118 DIP joint and 31 thumb IP joint) performed between 2012 and 2022. The primary outcome was risk factors for complications after arthrodesis. RESULTS: Osteoarthritis was the most common indication (56%) for arthrodesis. The majority of the patients were females (74%), and the median age was 62 (range 18-86). The complication frequency was 35%, with infection being the most common (25%). Time to completed follow up was < 12 weeks in the majority of the cases (58%). There were no significant differences in complication rate between the 136 joints operated using Kirschner wire and the 13 joints operated using headless compression screws. There was no significant increased risk of complications among smokers or patients with rheumatoid arthritis. Diabetes and surgeon experience had a significant influence on the risk of complication (p = 0.036 and p = 0.006, respectively). CONCLUSIONS: Osteoarthritis was the most common indication for arthrodesis and postoperative complications occurred at a rate similar to that reported in the existing literature. Diabetes and surgeon experience were identified as factors increasing the risk of postoperative complications in these DIP/thumb IP joint arthrodeses. However, there was no significant difference between the two techniques (Kirschner wire and headless compression screws) regarding complications. Further studies are needed in order to determine the optimal type of operation and choice of implant. TRIAL REGISTRATION: Researchweb CRIS #280,998, 26th of July 2023.

Efficacy of Minimally Invasive Ulnar Superficialis Slip Resection for Unfavourable Results after Trigger Finger Release.

Background: This study aimed to evaluate the efficacy of ulnar superficial slip resection (USSR) for improving hand function after unfavourable results after triggering finger release using a minimally invasive approach. Methods: We evaluated 17 consecutive fingers of 16 patients who complained of unfavourable outcomes after primary trigger finger release. The chief complaints of the two index and 15 middle fingers were proximal interphalangeal (PIP) joint pain during movement, flexion contracture of the PIP joint and snapping at the A2 pulley in eight, seven and two fingers, respectively. The joint arc of the active range of motion and extension loss of the PIP joint, grip strength, visual analogue score (VAS) of PIP joint pain and Quick Disability of the Arm, Shoulder and Hand were evaluated before and after surgery. Results: Thirteen fingers could release joint contracture and snapping by the USSR procedure. However, four fingers of three patients required total flexor digitorum superficialis resection to resolve the unsatisfactory conditions of the intraoperative decision. The joint arc of active range of motion and extension loss of the PIP joint, grip strength and VAS score significantly improved (mean of 16.1 months follow-up). Finally, 15 patients (88.2%) were satisfied with the symptom relief outcomes. Conclusions: USSR is an effective and satisfactory procedure for unfavourable conditions after trigger finger release, including PIP joint pain, joint contracture and snapping at the A2 pulley. Level of Evidence: Level IV (Therapeutic).

Surface replacing arthroplasty of a post-traumatic stiff and deviated proximal interphalangeal joint in an adolescent.

This case report describes the 4-year outcomes of proximal interphalangeal joint arthroplasty in a 14-year-old girl with a stiff joint after trauma. At follow-up, active range of motion was 35°, she was pain-free and satisfied with the outcome. Implant arthroplasty seems to be a valuable option for young patients with persistent post-traumatic stiff and deviated PIP joints to-at least temporarily-increase quality of life.

A marker-based approach to determine the centers of rotation of finger joints.

BACKGROUND AND OBJECTIVE: The methods proposed in literature to estimate the position of hand joints Centers of Rotation (CoRs) typically require computationally non-trivial optimization routines and exploit a high number of markers to calculate CoRs positions from surface marker trajectories. Moreover, most of the existing works evaluated the accuracy only in simulation. This work proposes a new procedure, based on the Pratt circle fit, to estimate joints CoRs position in 2D through marker-based acquisitions. METHODS: The advantage of the Pratt circle fit lies in its simplicity and computational speed, and in the possibility of exploiting a reduced markerset for calculating CoRs. By applying simplifying assumptions regarding the movement of the fingers (i.e., planar and decoupled flexion-extension movements of each joint occurring in the same flexion plane for all the joints of the finger), it is possible to determine the position of the CoR of each joint in 2D. For this reason, the estimation of the Carpo-MetaCarpal joint of the thumb was not included in this work, as it exhibits a more complex movement associated to the combination of a flexion-extension and adduction-abduction degree of freedom. The errors in estimating CoRs were evaluated by conducting experimental acquisitions on an anthropomorphic robotic hand and comparing the position of the estimated CoR with the real position of the CoR. The repeatability of the method and its capability to estimate anatomically plausible CoRs were evaluated through experimental acquisitions conducted on five healthy volunteers. RESULTS: Errors in estimating finger joints CoRs were in the order of 0.70 mm and 0.18 mm respectively along the finger longitudinal direction (i.e., x coordinate) and thickness (i.e., y coordinate). Standard Deviations of CoRs positions were comparable to the ones obtained in literature (i.e., below 2 mm and 1 mm respectively for the x and y coordinates), thus demonstrating the repeatability of the method. The Anatomical Plausibility Rate of the proposed approach was between 80% and 100%. CONCLUSIONS: The performance of the Pratt-based CoRs estimation procedure proposed in this work was comparable to other existing methods, with the advantage of exploiting a simple fitting algorithm and a reduced markerset with respect to the state-of-the-art techniques.

A Lightweight Dynamic Hand Orthosis With Sequential Joint Flexion Movement for Postoperative Rehabilitation of Flexor Tendon Repair Surgery.

During the postoperative hand rehabilitation period, it is recommended that the repaired flexor tendons be continuously glided with sufficient tendon excursion and carefully managed protection to prevent adhesion with adjacent tissues. Thus, finger joints should be passively mobilized through a wide range of motion (ROM) with physiotherapy. During passive mobilization, sequential flexion of the metacarpophalangeal (MCP) joint followed by the proximal interphalangeal (PIP) joint is recommended for maximizing tendon excursion. This paper presents a lightweight device for postoperative flexor tendon rehabilitation that uses a single motor to achieve sequential joint flexion movement. The device consists of an orthosis, a cable, and a single motor. The degree of spatial stiffness and cable path of the orthosis were designed to apply a flexion moment to the MCP joint prior to the PIP joint. The device was tested on both healthy individuals and a patient who had undergone flexor tendon repair surgery, and both flexion and extension movement could be achieved with a wide ROM and sequential joint flexion movement using a single motor.

What Plastic Surgeons Should Know about Small-Joint Arthroplasty: Is This for Your Practice?

SUMMARY: This article reviews the state of the art for arthroplasty of the metacarpophalangeal and proximal interphalangeal joints. Arthritis that affects these joints can result in significant pain and compromised function. The authors review indications for arthroplasty for each joint, types of implants to consider, technical considerations, patient expectations, and outcomes and complications.

Lambda Repair: A Novel Repair Technique for Chronic Boutonnière Deformity.

SUMMARY: Correction of a boutonnière deformity is one of the most demanding challenges in hand surgery. Surgical interventions are usually considered when functional use of the finger cannot be obtained after intense hand therapy. The authors introduce their newly described lambda (λ) repair, which is an easy-to-learn, straightforward surgical technique. The method involves an end-to-side tenorrhaphy of the lateral bands, resembling the Greek λ. Patients who underwent a lambda repair were retrospectively evaluated with preoperative and postoperative measurements of proximal interphalangeal (PIP) joint movement. Four patients (two male, two female; median age, 35.5 years) with a median follow-up period of 9.1 months were included. Three patients underwent lambda repairs for isolated boutonnière deformities, and one patient received a vascularized free toe transfer combined with a lambda repair. The preoperative average PIP joint extension lag or deficit was 28.75 degrees and could be reduced to 15 degrees. Preoperative average PIP joint active flexion was 60 degrees, which was improved to 88.75 degrees. No complications were observed. The lambda repair is a new tool in the reconstruction of boutonnière deformity, further expanding the armamentarium of hand surgeons.

A Novel Low-Pressure Robotic Glove Based on CT-Optimized Finger Joint Kinematic Model for Long-Term Rehabilitation of Stroke Patients.

Wearing robotic gloves has become increasingly crucial for hand rehabilitation in stroke patients. However, traditional robotic gloves can exert additional pressure on the hand, such as prolonged use leading to poor blood circulation and muscle stiffness. To address these concerns, this work analyzes the finger kinematic model based on computerized tomography (CT) images of human hands, and designs a low-pressure robotic glove that conforms to finger kinematic characteristics. Firstly, physiological data on finger joint flexion and extension were collected through CT scans. The equivalent rotation centers of finger joints were obtained using the SURF and RANSAC algorithms. Furthermore, the trajectory of finger joint end and the correlation equation of finger joint motion were fitted, and a comprehensive finger kinematic model was established. Based on this finger kinematic model, a novel under-actuated exoskeleton mechanism was designed using a human-machine integration approach. The novel robotic glove fully aligns with the equivalent rotation centers and natural motion trajectories of the fingers, exerting minimal and evenly distributed dynamic pressure on the fingers, with a theoretical static pressure value of zero. Experiments involving gripping everyday objects demonstrated that the novel robotic glove significantly reduces the overall pressure on the fingers during grasping compared to the pneumatic glove and the traditional exoskeleton robotic glove. It is suitable for long-term use by stroke patients for rehabilitation training.

The anatomy of the extensor tendon insertion in the arthritic distal interphalangeal joint: a cadaveric study.

Dissection of arthritic cadaveric digits revealed an expanded extensor tendon footprint involving the dorsal osteophyte on the terminal phalanx. Osteophyte attachments can be safely released up to the width of a number 15 scalpel blade without risking the integrity of the extensor tendon.

Pyrolytic Carbon Hemiarthroplasty for Proximal Interphalangeal Joint Arthritis, Long-Term Follow-Up.

PURPOSE: The purpose of this study was to assess the long-term clinical, subjective, and radiographic results of pyrocarbon hemiarthroplasty for proximal interphalangeal joint (PIPJ) arthritis at a single institution. METHODS: Patients treated with a pyrolytic carbon hemiarthroplasty between 2005 and 2015 were contacted for a clinical follow-up visit. Patients were assessed before surgery, one year after surgery, and again after a mean of 11 years (range: 6-16 years). Objective outcomes were assessed with grip strength, pinch strength, and range of motion (ROM). Subjective outcomes were assessed by the Disabilities of the Arm, Shoulder, and Hand score, Canadian Occupational Performance Measure (performance and satisfaction), and Visual Analog Scale pain scores at rest and during activity. Radiographic assessments were completed according to Sweets and Stern as modified by Wagner et al. RESULTS: A total of 68 fingers in 52 patients underwent PIPJ hemiarthroplasty. Thirty-six arthroplasties in 29 patients were available for the long-term follow-up, five patients had died, and the remaining cases were contacted by phone. Three cases were lost to follow-up. Preoperative diagnoses included 41 fingers with osteoarthritis or posttraumatic arthritis, and 27 fingers with inflammatory arthritis. Eight cases had undergone revision at the time of follow-up, and the 10-year implant survival was 72%. The revisions were performed after a mean of two years after surgery. Three patients had undergone soft-tissue procedures. Visual Analog Scale pain scores, Disabilities of the Arm, Shoulder, and Hand scores, and Canadian Occupational Performance Measure scores improved significantly compared with that before surgery. Grip strength and pinch grip remained unchanged. However, PIPJ ROM deteriorated significantly one year after surgery, when compared with that before surgery. CONCLUSIONS: Pyrocarbon hemiarthroplasty of the PIPJ has an acceptable long-term implant survival, and the significant improvement in pain scores and patient-reported outcomes is maintained over time. Pyrocarbon hemiarthroplasty could be a viable option in the management of PIPJ arthritis. Patients should be advised that PIPJ ROM deteriorates over time. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Proximal Interphalangeal Joint Fractures.

Multiple fracture patterns can occur around the proximal interphalangeal joint and require surgeons to have a thorough understanding of the anatomy, clinical and radiographic examination, common fracture patterns, surgical and nonsurgical treatment options, and potential complications. Proximal phalangeal condylar fractures are typically managed surgically, because even nondisplaced fractures have a propensity for displacement. Middle phalangeal base fractures most commonly present as a volar lip fracture with or without dorsal subluxation or dislocation. Treatment options include extension block splinting or pinning, transarticular pinning, open reduction and internal fixation, external fixation, volar plate arthroplasty, and hemihamate arthroplasty. Less common fractures include dorsal lip fractures with or without volar subluxation or dislocation (the central slip fracture), lateral plateau impaction or avulsion injuries, and pilon fractures. The main goals in the management of middle phalangeal base fractures are to restore articular congruency and initial early range of motion, which are more important than obtaining an anatomic reduction.

Quick and safe: why a k-wire-extension-block-fixation of a bony mallet finger is the favoured treatment.

INTRODUCTION: Mallet fingers are the most common tendon injuries of the hand. Bony avulsion distal finger extensor tendon ruptures causing a mallet finger require special attention and management. In this monocentral study, we analyzed the clinical and individual outcomes succeeding minimal invasive k-wire extension block treatment of bony mallet fingers. MATERIALS AND METHODS: In a retrospective study, we sent a self-designed template and a QUICK-DASH score questionnaire to all patients, who were treated because of a bony mallet finger between 2009 and 2022 and fulfilled the inclusion criteria. A total of 244 requests were sent out. 72 (29.5%) patients participated in the study. Forty-five men and twenty-seven women were included. RESULTS: 98.7% (n = 75) of the cases were successfully treated. Patients were highly satisfied with the treatment (median 8.0; SD ± 2.9; range 1.0-10.0). Based on the QUICK-DASH score, all patients showed no difficulties in daily life. The extent of avulsion did not influence the outcome. CONCLUSION: We conclude that the minimally invasive treatment of a bony mallet finger should be offered to every patient, because it is safe, fast, and reliable. Thus, we propose to perform extension-block pinning independently of the articular area.

Dorsal capsule release and lateral band translocation for a stiff swan neck deformity without articular involvement.

BACKGROUND: The treatment for proximal interphalangeal joint (PIP) stiffness in extension requires extensor tenolysis, concomitant procedures to restore flexion, and intensive therapy. A stiff swan neck deformity without articular involvement is rare and the treatment is always challenging. METHODS: Six patients with stiff swan neck deformities were operated between 2016 and 2023, and the outcome was analyzed retrospectively. A dorsal capsule release and radial lateral band translocation volar to the PIP joint axis were done. This translocation was maintained by a sling formed by the flexor digitorum superficialis and the free margins of the accessory collateral ligament. The range of movements in the PIP joint, visual analog scale (VAS), and functional outcomes were analyzed by the Michigan Hand Outcome Questionnaire (MHOQ) score. RESULTS: The mean follow-up was 49.5 months (range 48-52 months). The mean preoperative PIP joint extension was 8 (range 5-10) degrees of extension), and the mean preoperative PIP joint flexion was 0. All patients improved after the surgery and the mean flexion of the PIP joint at follow-up was 95 degrees; extension was 1 degree (range 0-5 degrees). The mean Michigan Hand Outcomes Questionnaire (MHOQ) score was 92 (range 90-95) and the VAS was 0. CONCLUSIONS: Dorsal capsule contracture release and lateral band translocation to the volar axis of the PIP joint seem to be the possibilities for correcting stiff swan neck deformity. LEVEL OF EVIDENCE: IV, retrospective case study.

The relation between synovitis of individual finger joints and grip force over the first 5 years in early rheumatoid arthritis - a cohort study.

OBJECTIVE: The objective of this study was to investigate the relation between swelling and tenderness of individual finger joints and grip force in patients with early rheumatoid arthritis (RA). METHODS: In an inception cohort of patients with early RA (symptom duration < 12 months), all patients were examined by the same rheumatologist, and grip force was measured using the Grippit instrument at inclusion, 1 and 5 years. The average grip force values of each hand were evaluated and expressed as % of expected values, based on age- and sex-specific reference values. Linear regression analyses were used to assess the cross-sectional relation between the involvement of individual finger joints and grip force. In generalized estimating equations, the impact of time-varying synovitis/tenderness on grip force over time was estimated. Analyses were adjusted for wrist involvement, erythrocyte sedimentation rate, and patient-reported pain. RESULTS: In 215 patients with early RA, grip force was 39% of expected at diagnosis, and increased to 56% after 5 years. Synovitis of the first metacarpophalangeal (MCP) joint (60% and 69% at baseline in the right and left hand) was associated with reduced grip force at inclusion (adjusted ß - 9.2 percentage unit of expected grip force; 95% CI - 13.6 to - 4.8 for both hands combined) and at all follow-up evaluations. Synovitis of MCP I and MCP IV (12% at baseline) was significantly associated with reduced grip force over time in both hands. Proximal interphalangeal (PIP) joint swelling, and tenderness of MCP or PIP joints, had less impact on grip force. CONCLUSION: MCP I synovitis is the major contributor to reduced grip force in patients with early RA. This underlines the importance of the involvement of the thumb for impaired hand function in RA. MCP IV synovitis, but not PIP involvement or finger joint tenderness, also has a substantial impact on grip force.

Charcot Arthropathy of the Digit: A Report of 2 Cases.

CASE: Charcot arthropathy (CA) is a progressive degenerative joint disease typically affecting lower extremity weight-bearing joints, with only a few cases reported in the fingers. We present 2 cases of interphalangeal joint CA: the long finger distal interphalangeal joint in a 73-year-old man with severe carpal tunnel syndrome and the ring finger proximal interphalangeal joint of a 71-year-old woman with diabetic neuropathy. CONCLUSION: Two cases of CA of the digits were treated with splinting with resolution of symptoms and no wound complications.

Coverage of Palmar Mini Plates with Flexor Pulleys in the Treatment of Dorsal Fracture-Subluxation of the Proximal Interphalangeal Joint.

Introduction: Dorsal fracture dislocations (DFD) of the proximal interphalangeal joint (PIPJ) are challenging fractures. A palmar surgical approach and plate fixation has a high complication rate, including flexor contractions, reduction of range of motion (ROM) and secondary need for plate removal. Methods: We use the flexor tendon pulleys to cover the mini plate with the assumption that it may reduce the adhesion between the mini plates and the tendons and reduce postoperative complications. We present the outcomes of using this technique in eight patients. Results: All patients had an excellent outcome at a mean follow-up of 17 months, and none required removal of the implants. Conclusions: This study presents a surgical technique that may potentially reduce the high complication rate found after ORIF for treatment of DFD of the PIPJ. Therefore, improving the clinical outcomes after this type of surgery. Level of Evidence: Level IV (Therapeutic).