Secondary Intention Healing for Fingertip Amputations in a Tropical Climate.

Background: Various studies have examined occlusive dressings in fingertip amputations and reported good outcomes. Occlusive dressing preserves appropriate pH, cell accumulation and moisture for healing, thereby limiting scar formation and deformity. To our knowledge, no study was performed in tropical Asia. This study aims to demonstrate the viability of healing fingertip amputations through secondary intention using an effective dressing technique, even in warm tropical climates. Methods: All patients who presented to our institution with fingertip amputations from 1 July 2020 to 31 July 2022 were analysed retrospectively. Seventeen patients (15 male, 2 female) of mean age 37.2 ± 9.4 years old with 18 injured digits were retrospectively analysed. Twelve (66.7%) were Allen Type III injuries, and one patient required distal phalangeal K-wire fixation. During the patient's final review, static 2-point discrimination, pulp sensation, fingertip contour and nail deformities alongside the last measured range of motion (ROM) of the injured finger was recorded. Treatment duration and days of leave taken were also summed and assessed. Results: Patients were dressed with semi-occlusive dressing for an average of 20.1 ± 6.83 days. The average total duration of dressing is 36.78 ± 18.88 days over an average of 7.18 ± 4.03 dressing visits. Mean duration of follow-up was 108 ± 63.46 days. Good outcome measures in sensation, pulp contour, nail deformity and ROM similar to existing literature were reported. Conclusions: Occlusive dressing remains a viable and feasible treatment option for fingertip amputation even in a tropical climate. While this simple treatment method may require more effort from patient, wound healing was attained after 36.8 ± 18.9 days of dressing. Level of Evidence: Level IV (Therapeutic).

Hand infection: a management approach based on a new understanding of combined bacterial and neutrophil mediated tissue damage.

Concepts of tissue damage from sepsis are rooted in the works of Pasteur regarding colonization by microorganisms, and Lister's observation of avoiding suppuration by their exclusion. The reactive inflammation has been considered a beneficial defence mechanism. A more complex biology is now unfolding of pathogenic mechanisms with toxins produced by the organisms now being placed in a broad category of virulence factors. Neutrophils are key cells in providing innate immunity and their trafficking to sites of infection results in entry to the extracellular space where they attack pathogens by release of the contents of neutrophil granules and neutrophil extracellular traps. There is now considerable evidence that much of the tissue damage in infection is due to excessive host innate immunological reaction; a hyperinflammatory response, whether localized or systemic. In addition to traditional surgical methods of drainage and decompression there is now a focus on dilution of inflammatory mediators. This emerging knowledge can potentially alter the way we approach hand infections.

First dorsal interosseous muscle reconstruction: a systematic review of its attachments.

PURPOSE: The first dorsal interosseous (FDI) muscle, when impaired due to traumatic injuries or degenerative conditions, can be reanimated in various ways to restore pinch grip. These reconstructive techniques are planned based on a precise anatomical understanding of the FDI muscle. However, a review of the existing literature has brought to light controversy regarding its insertions. A systematic review of these descriptions is presented to appreciate these variations. METHODS: An electronic database search without exclusion by publication year and language was performed according to the Checklist for Anatomical Reviews and Meta-Analyses (CARMA) guidelines, using the PubMed, Scopus, Web of Science and Embase databases. An assessment of the methodological quality was performed. RESULTS: Thirteen studies were included in this article. There is general agreement that the FDI muscle contains two bellies and a bony insertion into the index finger proximal phalanx base. However, due to wide anatomic variation, differences were reported on whether there is a soft tissue insertion. When this was found, the included studies differed on how commonly this occurs (between 1.4% and 78%), where it inserts. Other sites of distal insertions reported include the metacarpophalangeal capsule, the interosseous hood and an assemblage nucleus on the volar plate. CONCLUSIONS: Our systematic review, focusing on the insertion of the FDI muscle, summarizes the existing knowledge on its anatomy and variations, thereby facilitating better understanding of its function and surgical planning for reconstruction.

Understanding the biomechanics of the forearm during the dart thrower's motion.

This study investigated the contribution of different forearm muscles, namely the flexor carpi ulnaris, extensor carpi radialis longus and brevis, extensor carpi ulnaris and flexor carpi radialis, during the dart thrower's motion. Thirteen healthy participants were recruited. The forearm muscle activation patterns during the dart thrower's motion were measured using surface electromyography. The average root mean square for the extensor carpi ulnaris was found to be the highest during the dart thrower's motion. Muscle activations during the dart thrower's motion were heterogeneous among the participants. The results suggest the rehabilitation protocol for patients with wrist injuries should be reconsidered.

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 fluid-structure interaction investigation of intra-articular pressure and ligament in wrist joint.

Understanding the stresses on the scapholunate interosseous ligament (SLIL) and its interaction with synovial fluid pressure could be vital to improve wrist treatment for various wrist conditions such as arthritis, sprains and tendonitis. This study investigated the interaction between the intra-articular pressure, specifically the synovial fluid pressure change and the SLIL stresses in a computational model during wrist radioulnar deviation (RUD). Magnetic resonance imaging (MRI) scans were used to acquire the anatomical model of the carpal bones and ligament, while the kinematics of scaphoid and lunate were obtained through dynamic computerized tomography (CT) scans. A two-way fluid-structure interaction (FSI) was used to model the dynamics between the scaphoid and lunate, the SLIL, and the synovial fluid. The synovial fluid pressure change was found to be small (-4.86 to 3.23 Pa) and close to that simulated in a previous work without the SLIL (-1.68 to 2.64 Pa). Furthermore, peaks of maximum fluid pressure were found to trail the peaks of ligament stress. Therefore, it is suggested that the influence of synovial fluid pressure on the ligament in the SLIL model is negligible and simulations of the scapholunate joint could forego fluid-structure interactions. Future studies can instead explore other structures in the carpus that can possibly contribute to the ligament stresses. Clinically, treatments can be targeted at these areas to help prevent or slow the progression of ligament injuries into serious consequences like the degenerative joint disease.

Biomechanical Study of Modified Massachusetts General Hospital Flexor Tendon Repair Using Looped Sutures.

Background: Massachusetts General Hospital (MGH) repair is one of the widely used 4-strand flexor tendon repair techniques. However, it uses two single strand sutures that are each passed twice across the repair site. This is time consuming and may cause imbalance of the load across the repair. We modified the MGH repair by using a looped suture and call it the looped MGH repair. The aim of this study is to compare the strength of the looped MGH repair performed with three different looped sutures against the strength of original MGH repair. Methods: Forty porcine flexors were used for the study. The original MGH repair was performed with Prolene® 4-0. Looped MGH repair was performed with three different loop sutures, Supramid® 4-0, Tendo-Loop® 4-0 and FiberLoop® 4-0. Mechanism of failure, ultimate tensile strength, stiffness, load to 2-mm gap formation and repair time were recorded for comparison. Results: There was no significant difference between the original MGH repair and the looped repair using Supramid® regarding their biomechanical performance. Looped MGH repair using Tendo-Loop® and FiberLoop® showed significantly higher ultimate tensile strength and FiberLoop® had highest 2-mm gap force. All looped MGH repairs required significant less time compared to original MGH repair. Conclusions: Our modification of the MGH repair using a looped Supramid® 4-0 suture took significantly lesser time to perform while providing the same strength as the original MGH repair using Prolene® 4-0. The use of the FiberLoop® 4-0 provided significantly greater strength while taking lesser time.

Delivery of Wnt inhibitor WIF1 via engineered polymeric microspheres promotes nerve regeneration after sciatic nerve crush.

Injuries within the peripheral nervous system (PNS) lead to sensory and motor deficits, as well as neuropathic pain, which strongly impair the life quality of patients. Although most current PNS injury treatment approaches focus on using growth factors/small molecules to stimulate the regrowth of the injured nerves, these methods neglect another important factor that strongly hinders axon regeneration-the presence of axonal inhibitory molecules. Therefore, this work sought to explore the potential of pathway inhibition in promoting sciatic nerve regeneration. Additionally, the therapeutic window for using pathway inhibitors was uncovered so as to achieve the desired regeneration outcomes. Specifically, we explored the role of Wnt signaling inhibition on PNS regeneration by delivering Wnt inhibitors, sFRP2 and WIF1, after sciatic nerve transection and sciatic nerve crush injuries. Our results demonstrate that WIF1 promoted nerve regeneration (p < 0.05) after sciatic nerve crush injury. More importantly, we revealed the therapeutic window for the treatment of Wnt inhibitors, which is 1 week post sciatic nerve crush when the non-canonical receptor tyrosine kinase (Ryk) is significantly upregulated.

Peripheral Vein Thrombophlebitis in the Upper Extremity: A Systematic Review of a Frequent and Important Problem.

BACKGROUND: The acceptable incidence of thrombophlebitis following intravenous cannulation is 5%, as recommended by the Intravenous Nurses Society guidelines, but publications have reported startling figures of 20% to 80%. Given the frequency of intravenous lines, this presents a potential clinical problem. We aimed to determine the predisposing patient, catheter, and health care-related factors of peripheral vein thrombophlebitis in the upper extremity. METHODS: In this systematic review, we used a comprehensive search strategy to identify risk factors of thrombophlebitis from inception to May 20, 2019. Studies reporting risk factors of peripheral vein thrombophlebitis of adult patients admitted to the hospital and receiving an intravenous cannulation were included. The Quality of Prognostic Studies tool was used in the assessment for risk of bias to determine the study quality. RESULTS: Of the 6910 studies initially identified, 25 were eligible for inclusion. Qualitative syntheses revealed that patient-related factors that confer a higher risk included intercurrent illness, immunocompromised state, comorbidities such as diabetes mellitus, malignancy, previous thrombophlebitis, burns, and higher hemoglobin levels. Catheter-related risk factors included catheter size, duration, and site of insertion. Intravenous antibiotics and potassium chloride predisposed to thrombophlebitis. Cannulation by an intravenous therapy team and more nursing care were associated with a decreased risk. A P-value < .5 was considered to be statistically significant. CONCLUSION: Recognition of the predisposing factors would allow for targeted strategies to aid in the prevention of this iatrogenic infection, which may include closer monitoring of patients who are identified to be vulnerable. Based on this systematic review, we developed an algorithm to guide clinical management. Further research is warranted to validate this algorithm.

Biomechanical evaluation of peripheral nerves after crush injuries.

BACKGROUND: Crush injury of nerves is a common condition but the biomechanical integrity of the human peripheral nerve after crushing is unknown. This study aims to investigate the impact of crush injury on human digital nerves based on different compressive forces. MATERIALS AND METHODS: Twenty digital nerves were harvested from three fresh-frozen cadaver hands. The original diameters of proximal, middle and distal end of nerve segment were measured. The midst of each digital nerve was compressed by a customized mechanical system, at 1N, 3N and 5N for 30sec. The diameters were measured again within 1 minute after the nerve crush test was performed. The digital nerve was then subjected to biomechanical test to measure its ultimate tensile strength, stiffness, maximum stress and strain. Deformity of digital nerve was computed based on the diameter of middle nerve segment before and after crush test. RESULTS: No significant difference was found in between groups for ultimate tensile strength (p=0.598), stiffness (p=0.593), maximum stress (p=0.7) and strain (p=0.666). The deformity of nerves under the compression of 1N, 3N and 5N was computed at 72.1%, 54.2% and 45.9%. The effect of compression on the deformity of nerves was statistically significant (p<0.001). CONCLUSIONS: It was found that the compressive forces have no impact on the biomechanical integrity of peripheral nerves but the deformity of nerves could be severely caused by low compressive force. It is suggested that the management of nerve crush injury shall be taken immediately and focus on neurophysiological function and degeneration of nerves for a crush with low compressive force and short duration.

Are Flexor Tendon Ruptures Ever Spontaneous? - A Literature Review on Closed Flexor Tendon Ruptures of the Little Finger.

Background: When closed ruptures of flexor tendons of fingers occur, there is often an identifiable pathology, which should be addressed in the same surgical setting as the tendon repair. The concept of "spontaneous" tendon rupture, occurring in the absence of identified pathology, however, has also been reported in a significant number of papers. This controversy has prompted us to do a review of the existing literature. Methods: We did a review of cases of closed ruptures of the flexor digitorum profundus (FDP) of the little finger in existing literature. Fifty-three publications were retrieved by searching "FDP tendon rupture" and "little finger" using PubMed database. We analyzed data such as the zone of rupture noted intra-operatively; and any precipitating factors, pathology or trauma. We also conducted a review on papers which discussed the concept of "spontaneous rupture". Results: Fifty-three publications were retrieved. There were 8 cases of ruptures in Zone I; 2 in Zone II; 30 in Zone III; 59 in Zone IV and 5 in Zone V. Majority of cases were associated with an element of trauma of varying severity, or pathology. A precipitating cause was not documented in 12 cases. Amongst all 36 cases of ruptures labelled as "spontaneous", only 1 case was truly "spontaneous" without any associated trauma or pathology. Conclusions: Most reports labeled as spontaneous rupture occurred in Zone III, where tendon ruptures are rare. There are documented pathological causes or evidence of trauma to most of these cases. We conclude these ruptures may have been mislabeled as spontaneous ruptures. Bearing in mind the propensity for tendon excursion, we suspect the lack of documentation of exploration in proximal zones contributed to this mislabeling. Understanding this concept of non-spontaneity to most tendon ruptures and the common sites of rupture or pathology is crucial for a surgeon to make strategic incisions and minimize future recurrence.

Techniques for Continuous Irrigation of Septic Joints of the Hand.

Septic arthritis of the small joints of the hand usually occurs secondary to bacterial inoculation through penetrating injury to the joint, or direct spread of infection from paronychia, felon, or pyogenic flexor tenosynovitis. Surgical treatment involves drainage and irrigation and may involve debridement if there is an open wound. We describe a method of continuous irrigation of septic joints of the hand postoperatively in the ward setting using an intravenous cannula placed within the joint and connected to an intravenous giving set with delivery of physiological fluid using a pump driver. Modifications of the technique are described for distal interphalangeal, proximal interphalangeal, and metacarpophalangeal joints and illustrated in each joint by 3 case studies. In addition to the irrigation, intravenous antibiotics were administered. All patients healed well with a full return of joint motion, no radiologic change, and a mean QuickDASH score of 4.8 at a mean follow-up duration of 3.6 months. This is a safe and simple technique that can be performed in patients with suspected or confirmed septic arthritis and carries minimal morbidity.

A randomized controlled trial comparing ketorolac and triamcinolone injections in adults with trigger digits.

We assessed the efficacy of ketorolac trometamol injections compared with triamcinolone acetonide injections in trigger digits. Patients with trigger digits were randomized to receive either ketorolac or triamcinolone. They were followed up at 3, 6, 12 and 24 weeks, and monitored for resolution of triggering, pain and total active motion. One hundred and twenty-one patients with single trigger digits were recruited (59 ketorolac, 62 triamcinolone). At 6 weeks, 54% of patients in the triamcinolone group had complete resolution of trigger, whereas no patients in the ketorolac group had resolution. At 12 weeks, 58% of patients in the triamcinolone group had complete resolution of trigger compared with 6.7% in the ketorolac group. At 24 weeks, both groups had comparable rates of resolution at 26% and 25%, respectively. Patients in the triamcinolone group had significantly better resolution of pain at 3, 6 and 12 weeks. But at 24 weeks, there was no significant difference in pain between both groups. Significantly less flexion deformity was reported at 3 weeks and 6 weeks in the triamcinolone group. In the short term, ketorolac was less effective in relieving symptoms of trigger digit than triamcinolone. Level of evidence: I.

A Biomechanical Comparison of Different Knots Tied on Fibrewire Suture.

BACKGROUND: Synthetic sutures such as Fiberwire used in flexor tendon repairs have high tensile strength. Proper application allows early mobilisation, decreasing morbidity from repair rupture and adhesions while preserving range of motion. Suture stiffness can cause poorer knot holding, contributing to gapping, peritendinous adhesions or rupture. Previous studies recommended more throws in knots tied on Fiberwire to prevent knot slippage. These larger knots are voluminous and prominent. In tendon repairs they can cause "catching", increase friction and work of flexion. Other studies advocated certain complicated knots as being more secure. We evaluated several knots and their biomechanical properties with the aim of finding a compact knot with less potential for slippage to maximise strength potential of flexor tendon repairs using Fiberwire. METHODS: A series of different knots tied on Fiberwire 4-0 sutures were pulled to failure on a mechanical tester. Mean tensile strengths, knot volumes and tensile strength to knot volume ratios were compared. RESULTS: Tensile strengths and knot volume increased with more throws and loops. Four variations of the square knot (the 4=4=1, 2=2=2=2, 1=1=1=1=1, 2=1=1=1=1 knots) had tensile strengths greater than 35N. The specialised anti-slip knot had highest tensile strength and suture volume but lower strength-to-volume ratio. CONCLUSIONS: The anti-slip knot had highest tensile strength but it also had the highest volume. The greater strength of repair may not translate into improved clinical outcome. The 1=1=1=1=1 knot has superior knot strength-to-volume ratio with good knot strength adequate for early active mobilisation in flexor tendon repairs.

The natural history and spontaneous resolution of keloid scars.

INTRODUCTION: There is limited information available on the natural history and prognosis of keloid scars. AIM: To evaluate how keloid scars behave over time to develop prognostic information for patients. MATERIALS AND METHODS: 34 patients in Manchester and Barbados (average age 34 years) yielding 126 keloids completed questionnaires about their lesions. RESULTS: 46 keloids (37%) were described by patients as resolved, meaning they were satisfactory in appearance, not symptomatic and not requiring treatment. In each case the scar remained visible. 36 (29%) lesions resolved following treatment. Ten (8%) resolved spontaneously. The median number of years to resolution with treatment was 11.4 and to spontaneous resolution was 5, this difference was statistically significant (p < 0.05). The median number of years since resolution with treatment was 3 and since spontaneous resolution was 18, this difference was statistically significant (p < 0.0001). Seventeen lesions (13%) were resolving with treatment. 63 (50%) remained active. Overall the median number of years scars persisted was 15. CONCLUSION: Keloids never completely disappear to leave skin with normal texture, however they can resolve (flatten and soften) so they no longer burden patients in approximately one third of cases. Scars resolving spontaneously do so early in the disease. Those that don't may resolve after many years of treatment. This data can provide prognostic information to patients, and a baseline for future therapeutic trials.

A novel in vitro assay for electrophysiological research on human skin fibroblasts: degenerate electrical waves downregulate collagen I expression in keloid fibroblasts.

Electrical stimulation (ES) has been used for the treatment of wounds and has been shown to alter gene expression and protein synthesis in skin fibroblasts in vitro. Here, we have developed a new in vitro model system for testing the effects of precisely defined, different types of ES on the collagen expression of normal and keloid human skin fibroblasts. Keloid fibroblasts were studied because they show excessive collagen production. Both types of fibroblasts were electrically stimulated with alternating current (AC), direct current (DC) or degenerate waves (DW). Cells were subjected to 20, 75 and 150mV/mm electric field strengths at 10 and 60Hz frequencies. At lower electric fields, all types of ES upregulated collagen I in both cell types compared to controls. However, at higher electric field strength (150mV/mm) and frequency (60Hz), DW maximally downregulated collagen I in keloid fibroblasts, yet had significantly lower cytotoxic effects on normal fibroblasts than AC and DC. Compared to unstimulated cells, both normal skin and keloid fibroblasts showed a significant decrease in collagen I expression after 12h of DW and AC stimulation. In contrast, increasing amplitude of DC upregulated collagen I and PAI-1 gene transcription in normal and keloid fibroblasts, along with increased cytotoxicity effects. Thus, our new preclinical assay system shows highly differential effects of specific types of ES on human fibroblast collagen expression and cytotoxicity and identifies DW of electrical current (DW) as a promising, novel therapeutic strategy for suppressing excessive collagen I formation in keloid disease.