Profundus Tendon Research Articles

Biomechanical Comparison of Three Modified Kessler Techniques for Flexor Tendon Repair: Implications in Surgical Practice and Early Active Mobilization.

Objective: Managing flexor tendon injuries surgically remains challenging due to the ongoing debate over the most effective suture technique and materials. An optimal repair must be technically feasible while providing enough strength to allow for early active mobilization during the post-operative phase. This study aimed to assess the biomechanical properties of three modified Kessler repair techniques using two different suture materials: a conventional two-strand and a modified four-strand Kirchmayr-Kessler repair using 3-0 Prolene® (2s-KK-P and 4s-KK-P respectively), and a four-strand Kessler-Tsuge repair using 4-0 FiberLoop® (4s-KT-FL). Methods: Human flexor digitorum profundus (FDP) tendons were retrieved from Thiel-embalmed prosections. For each tendon, a full-thickness cross-sectional incision was created, and the ends were reattached using either a 2s-KK-P (n = 30), a 4s-KK-P (n = 30), or a 4s-KT-FL repair (n = 30). The repaired tendons were tested using either a quasi-static (n = 45) or cyclic testing protocol (n = 45). Maximum force (Fmax), 2 mm gap force (F2mm), and primary failure modes were recorded. Results: In both quasi-static and cyclic testing groups, tendons repaired using the 4s-KT-FL approach exhibited higher Fmax and F2mm values compared to the 2s-KK-P or 4s-KK-P repairs. Fmax was significantly higher with a 4s-KK-P versus 2s-KK-P repair, but there was no significant difference in F2mm. Suture pull-out was the main failure mode for the 4s-KT-FL repair, while suture breakage was the primary failure mode in 2s- and 4s-KK-P repairs. Conclusions: FDP tendons repaired using the 4s-KT-FL approach demonstrated superior biomechanical performance compared to 2s- and 4s-KK-P repairs, suggesting that the 4s-KT-FL tendon repair could potentially reduce the risk of gapping or re-rupture during early active mobilization.

Cell-based tissue engineered flexor tendon allograft: A canine in vivo study.

This study aimed to compare the clinically established autologous extrasynovial tendon graft to a newly developed tissue-engineered allograft (Eng-allograft) in terms of functional outcomes following flexor tendon reconstruction in a canine model. The second and fifth flexor digitorum profundus (FDP) tendons from 16 dogs were transected and repaired in Zone II. After 6 weeks of cage activity, the repaired tendons were intentionally ruptured, creating a clinically relevant model for reconstruction. The re-ruptured FDP tendons were then reconstructed using either the clinically standard autologous extrasynovial tendon graft or the Eng-allograft, which had been revitalized with autologous bone marrow-derived mesenchymal stem cells (BMSCs) and synovialized using carbodiimide derivatized synovial fluid (cd-SYN). Following 12 weeks of postoperative rehabilitation, the functional outcomes of the surgical digits were evaluated. The Eng-allograft group exhibited improved digital function, including lower digit work of flexion and reduced adhesion status, while maintaining similar tendon gliding resistance compared to the autograft group. However, the failure load of both the distal and proximal host/graft conjunctions in the Eng-allograft group was significantly lower than that of the autograft group with higher graft rupture at the host-graft junction. In conclusion, the decellularized allogenic intrasynovial tendon, when revitalized BMSCs and synovialized with cd-SYN, demonstrates positive effects on digital function improvement and adhesion reduction. However, the healing at both proximal and distal graft/host junctions is far lower than the autograft. Further research is needed to enhance the healing capacity of allograft conjunctions, aiming to achieve a comparable level of healing seen with autografts.

Antioxidant Carbon Dots and Ursolic Acid Co-Encapsulated Liposomes Composite Hydrogel for Alleviating Adhesion Formation and Enhancing Tendon Healing in Tendon Injury.

The formation of adhesion after tendon injury represents a major obstacle to tendon repair, and currently there is no effective anti-adhesion method in clinical practice. Oxidative stress, inflammation, and fibrosis can occur in tendon injury and these factors can lead to tendon adhesion. Antioxidant carbon dots and ursolic acid (UA) both possess antioxidant and anti-inflammatory properties. In this experiment, we have for the first time created RCDs/UA@Lipo-HAMA using red fluorescent carbon dots and UA co-encapsulated liposomes composite hyaluronic acid methacryloyl hydrogel. We found that RCDs/UA@Lipo-HAMA could better attenuate adhesion formation and enhance tendon healing in tendon injury. RCDs/UA@Lipo-HAMA were prepared and characterized. In vitro experiments on cellular oxidative stress and fibrosis were performed. Reactive oxygen species (ROS), and immunofluorescent staining of collagens type I (COL I), collagens type III (COL III), and α-smooth muscle actin (α-SMA) were used to evaluate anti-oxidative and anti-fibrotic abilities. In vivo models of Achilles tendon injury repair (ATI) and flexor digitorum profundus tendon injury repair (FDPI) were established. The major organs and blood biochemical indicators of rats were tested to determine the toxicity of RCDs/UA@Lipo-HAMA. Biomechanical testing, motor function analysis, immunofluorescence, and immunohistochemical staining were performed to assess the tendon adhesion and repair after tendon injury. In vitro, the RCDs/UA@Lipo group scavenged excessive ROS, stabilized the mitochondrial membrane potential (ΔΨm), and reduced the expression of COL I, COL III, and α-SMA. In vivo, assessment results showed that the RCDs/UA@Lipo-HAMA group improved collagen arrangement and biomechanical properties, reduced tendon adhesion, and promoted motor function after tendon injury. Additionally, the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) in the RCDs/UA@Lipo-HAMA group increased; the levels of cluster of differentiation 68 (CD68), inducible Nitric Oxide Synthase (iNOS), COL III, α-SMA, Vimentin, and matrix metallopeptidase 2 (MMP2) decreased. In this study, the RCDs/UA@Lipo-HAMA alleviated tendon adhesion formation and enhanced tendon healing by attenuating oxidative stress, inflammation, and fibrosis. This study provided a novel therapeutic approach for the clinical treatment of tendon injury.

Case series on Linburg-Comstock Variation in Sri Lanka

The case series present a rare anatomical variation involving an anomalous connection between the flexor pollicis longus and flexor digitorum profundus tendons in the forearm called Linburg-Comstock variation. These three cases were identified in Sri Lankan population, highlighting the presence of this variation in the local population. The unique anatomical details and potential implications for hand function in individuals with Linburg-Comstock variation are discussed.

Effect of Heparin on Post-Operative Ultrasonographic Changes in Flexor Digitorum Profundus Tendon Trauma Of The Hand

Abstract Background Flexor tendon injuries especially zone II are a challenging problem for both surgeons and patients as they need careful post-operative early physiotherapy to decrease adhesions and improve gliding which carry risk of early tendon rupture. Many drugs were tested for their role in decreasing paratendinous adhesions and enhance clinical outcome, this study by ultrasound examination test effect of intraoperative addition of heparin in limiting paratendinous adhesions and improving clinical outcome. Aim of the Work to evaluate the effect of intraoperative heparin addition in preventing postoperative adhesions and on clinical outcome. Patients and Methods This clinical trial study included 21 patients with 31 surgically repaired zone II flexor digitorum profundus tendons. The 21 Patients were divided randomly into two groups, group A (study group) with heparin injection during surgical repair and group B (control group) without heparin injection, with a total number of eleven patients in group I and ten patients in group II. Results There was no statistically significant difference between the two groups in tendon margins, gliding or granulation tissue severity, which can support why it does not affect clinical outcome. There was no statistically significant relation between the heparin injection and tenosynovitis although heparin is known for its anti-inflammatory effect. Tendon re rupture was more presented in heparin injected group yet not of statistical significance. Conclusion The intraoperative heparin injection at repair site didn’t show any significance in enhancing clinical outcome or in limiting paratendinous adhesions. Although it wasn’t of statistical significant but tendon re-rupture was more seen in cases managed with heparin injection group so heparin injection is not recommended in treatment such cases yet further investigations are needed.

The effect of the number of strands and knot throws of core suture techniques on the mechanical properties of the repaired flexor tendon.

Flexor tendon injury is a common hand trauma that requires surgical repair. The objective was to compare the repaired strength and gliding resistance with a varied number of repair strands and of square knots using a two-strand-overhand locking (TSOL) knot. First, isolated suture loops with different number of suture strands and number of closing knots were compared in mechanical strength and failure mode. Then, 90 flexor digitorum profundus (FDP) tendons from turkey digits were used for the tendon repair experiment. Both phases followed a similar 3 × 3 matrix comparing the knot type including TSOL+1SK (square knot), TSOL+2SK, and TSOL+3 SK and repair techniques including two-, four-, and six-strand repairs techniques respectively. The repaired tendons were tested for tendon resistance against pulley (friction), maximum force, force at 2 mm displacement, stiffness, and failure mode. Increasing the number of strands and closing square knots increases the tensile strength and stiffness of flexor tendon repairs and isolated suture loops without a significant effect on tendon friction. An increase in the number of square knots have shown increased strength only in Pennington repair, which correlated with the increased number of knot unraveling, a weak knot failure model. Our data demonstrated that increasing the number of strands is effective for improving the overall strength of tendon repair. When a two-strand repair is chosen, increasing knot number can improve repair strength. However, the number of knots appears not affecting repair strength in six-strand repair technique.

All-Suture Anchor Techniques for Biceps Tenodesis Are Noninferior in End-Cycle Stiffness to an Interference Screw Technique; However, Secondary Outcomes, Such as Ultimate Failure Load, Yield Load, Creep, and Load-to-Failure Stiffness, Are Inferior in an Ovine Model

PurposeThe purpose of this study was to assess the biomechanical performance of two simplified loop and tack biceps tenodesis techniques, all-suture anchor and all-suture anchor with a button, compared to the interference screw technique in an ovine model. MethodsTwenty-one biceps tenodesis procedures were executed on the humeri and flexor digitorum profundus tendons of skeletally mature, female sheep. Limbs were evenly randomized into two experimental groups (all-suture anchor with/without button) and one control group (interference screw). Cyclic loading followed by a load-to-failure test was conducted.The primary outcome metric was end-cycle stiffness, or stiffness measured at the end of cyclic loading, as it modeled the resistance of the construct to the lower-force activities of postoperative physical therapy. Secondary metrics included ultimate failure load (UFL), yield load, creep, and load-to-failure stiffness. End-cycle stiffness difference-of-means testing was conducted with a minimal clinically significant difference (MCID) threshold of -15N/mm (1.5kg/mm). Groups were compared using ANOVA for all recorded variables. ResultsBoth the all-suture anchor and all-suture anchor with button techniques were found to be noninferior in end-cycle stiffness compared to the interference screw technique (-5.2N/mm, 95% CI [-13.6, 3.3] and –3.8N/mm, 95% CI [-12.5, -4.9]) for -15N/mm MCID. The all-suture techniques showed significantly lower UFL, lower yield load, greater creep, and lower load-to-failure stiffness (P<0.001, P<0.001, P=0.002, P<0.001, respectively). Tendon dimensions did not vary significantly across groups. ConclusionsUnder subfailure loading conditions, the all-suture anchor with/without button techniques demonstrated end-cycle stiffness noninferiority with an interference screw technique, however, these techniques were inferior in all secondary outcomes, including significantly lower UFL, lower yield load, greater creep, and lower load-to-failure stiffness. Clinical RelevanceThe all-suture anchor with/without button approaches may retain the natural length-tension dynamics of the long head biceps tendon as fixation can occur before releasing the tendon origin. Additionally, it may offer a simpler and more cost-effective alternative to prevailing arthroscopic methods.

An unusual case of nodular fasciitis presenting as an intra-tendinous mass.

Nodular fasciitis is a benign soft tissue pseudotumour typically occurring in the upper extremities, head and neck, thigh and trunk. It is most commonly seen in subcutaneous locations but also can be present in intramuscular and intermuscular (fascial) locations. Its occurrence in the hand is rare, and while it can occur in close proximity to tendons, its presentation as an intra-tendinous mass has not been previously described. We present a unique and rare case of nodular fasciitis arising within the flexor digitorum profundus (FDP) tendon of the hand in a 16-year-old female. The patient presented with a painful swelling in the volar aspect of the base of her left middle finger, with progressive flexion deformity of the finger. Ultrasound and magnetic resonance imaging revealed a mass within the FDP tendon of the middle finger. An ultrasound-guided biopsy revealed a diagnosis of nodular fasciitis. Given the self-limiting nature of the condition, she was managed conservatively with close clinical and imaging follow-up. This case highlights the importance of considering nodular fasciitis in the differential diagnosis of an intra-tendinous lesion in the hand, even though it is a rare occurrence in this location. The clinical presentation, diagnostic workup, and management of this unique case are discussed, emphasising the potential for its misdiagnosis as a malignancy which can have important implications in management.

Pathomechanics of lumbrical and flexor digitorum profundus muscle tears in climbers: A cadaveric model

Lumbrical muscles originate on the flexor digitorum profundus (FDP) tendons and, during fist making, they move in the same direction when FDP muscle produces maximal proximal tendon gliding. Injuries of the bipennate lumbricals have been described when a shear force acts between the origins on adjacent tendons of the FDP, as they glide in opposite directions in asymmetric hand postures. Other structures of the deep flexors complex can be affected during this injury mechanism, due to the so-called quadriga effect, which can commonly occur during sport climbing practise. Biomechanical studies are needed to better understand the pathomechanism. A cadaveric study was designed to analyse the effects of load during the fourth lumbrical muscle injury mechanism. The amount of FDP tendon gliding and metacarpophalangeal (MCP) joint flexion of the 5th finger were calculated. Ten fresh-frozen cadaveric specimens (ten non-paired forearms and hands) were used. The specimens were placed on a custom-made loading apparatus. The FDP of the 5th finger was loaded, inducing isolated flexion of the 5th finger, until rupture. The rupture occurred in all specimens, under a load of 11 kg (SD 4.94), at 9.23 mm of proximal tendon gliding (SD 3.55) and at 21.4° (SD 28.91) of MCP joint flexion. Lumbrical muscle detachment from the 4th FDP was observed, from distal to proximal, and changes in FDP tendons at the distal forearm level too. The quadriga effect can lead to injury of the bipennate lumbrical muscles and the deep flexors complex in the hand and forearm.

Anatomical design and production of a novel three-dimensional co-culture system replicating the human flexor digitorum profundus enthesis.

The enthesis, the specialized junction between tendon and bone, is a common site of injury. Although notoriously difficult to repair, advances in interfacial tissue engineering techniques are being developed for restorative function. Most notably are 3D invitro co-culture models, built to recreate the complex heterogeneity of the native enthesis. While cell and matrix properties are often considered, there has been little attention given to native enthesis anatomical morphometrics and replicating these to enhance clinical relevance. This study focuses on the flexor digitorum profundus (FDP) tendon enthesis and, by combining anatomical morphometrics with computer-aided design, demonstrates the design and construction of an accurate and scalable model of the FDP enthesis. Bespoke 3D-printed mould inserts were fabricated based on the size, shape and insertion angle of the FDP enthesis. Then, silicone culture moulds were created, enabling the production of bespoke anatomical culture zones for an invitro FDP enthesis model. The validity of the model has been confirmed using brushite cement scaffolds seeded with osteoblasts (bone) and fibrin hydrogel scaffolds seeded with fibroblasts (tendon) in individual studies with cells from either human or rat origin. This novel approach allows a bespoke anatomical design for enthesis repair and should be applied to future studies in this area.

Secondary Repair of Jersey Finger: A Novel Method of Tendon Length Estimation via Measurement of Adjacent Landmarks.

Jerseyfinger describes the rupture of the flexor digitorum profundus (FDP) tendon at its insertion into the distal phalanx. In the absence of an evidence-based approach to tensioning during secondary repair, we aimed to devise a novel method to determine the required tendon length pre/intraoperatively. We measured anatomical landmarks, associated with the FDP tendon, on dissected cadavers, to assess whether these can be used to estimate tendon segment lengths. Eight cadaveric hands were dissected. Three measurements from the distal lumbrical origin to (1) FDP insertion, (2) the distal end of A1 (Annular 1 pulley), and (3) the proximal end of A1 were recorded for digits II-V. Relative ratios for measurement 1were consistent for all digits, compared to digit III. Linear regression analysis confirmed a strong correlation for measurement 1between digit II (R2=0.97) and digit IV(R2=0.97)compared to digit III across all specimens. Digit III distal lumbrical origin to FDP insertion measurements could facilitate the estimation of the required graft length for digit II or IV during secondary repair. This is alevelIV study, providing proofof concept for a novel method of tendon tensioning.

Clinical characteristics and treatment analysis of three cases of congenital ulnar collateral flexor contracture of the forearm

To report the clinical characteristics and treatment analysis of 3 cases of congenital ulnar collateral flexor contracture of the forearm and take a reference for clinic. A total of 3 patients with congenital ulnar collateral flexor contracture of the forearm were admitted between February 2019 and August 2021. Two patients were male and 1 was female, and their ages were 16, 20, and 16 years, respectively. The disease durations were 8, 20, and 15 years, respectively. They all presented with flexion deformity of the proximal and distal interphalangeal joints of the middle, ring, and little fingers in the neutral or extended wrist position, and the deformity worsened in the extended wrist position. The total action motion (TAM) scores of 3 patients were 1 and the gradings were poor. The Carroll's hand function evaluation scores were 48, 55, and 57, and the grip strength indexes were 72.8, 78.4, and 30.5. Preoperative CT of case 2 showed a bony protrusion of the flexor digitorum profundus tendon at the proximal end of the ulna; and MRI of case 3 showed that the ulnar flexor digitorum profundus presented as a uniform cord. After diagnosis, all patients were treated with operation to release the denatured tendon, and functional exercise was started early after operation. The incisions of 3 patients healed by first intention. Three patients were followed up for 12, 35, and 12 months, respectively. The hand function and the movement range of the joints significantly improved, but the grip strength did not significantly improve. At last follow-up, TAM scores were 3, 4, and 4, respectively, among which 2 cases were excellent and 1 case was good. Carroll's hand function evaluation scores were 95, 90, and 94, and the grip strength indexes were 73.5, 81.3, and 34.2, respectively. Congenital ulnar collateral flexor contracture is a rare clinical disease that should be distinguished from ischemic muscle contracture. The location of the contracture should be identified and appropriate surgical timing should be selected for surgical release. Active postoperative rehabilitation and functional exercise can achieve good hand function.

Distal forearm squeeze test for the diagnosis of digital flexor tendon injuries

BackgroundThe forearm/wrist squeeze/compression test has been used to examine digital flexor tendon injuries with varied names. Furthermore, the test has not been minutely described and its mechanism remains unclear. We renamed the test the “distal forearm squeeze test”. The purpose of this study was to elaborate on the test and elucidate the mechanism.MethodsTwo patients with digital flexor tendons ruptured in zone 3 and zone 1 respectively and 50 outpatients with intact digital tendons underwent the test. Then the test was performed on 3 chickens under 4 conditions. First, when the digital flexor and extensor tendons were all intact. Second, after the flexor tendons of the third toe were transected. Third, after the flexor tendons of all toes of the foot were transected. Finally, after the flexor and extensor tendons of all toes of the foot were transected.ResultsIn the patient with digital flexor tendons ruptured in zone 3, the test showed that the injured digit was flexed slightly while the uninjured digits were flexed obviously. In the patient with digital flexor tendon ruptured in zone 1, after separate stabilization of the proximal interphalangeal (PIP) joints of the injured and uninjured fingers in extension, the test showed that the distal interphalangeal joint of the patient’s injured finger had no response, while those of the uninjured fingers were flexed. All 50 subjects showed clenched or half-clenched hands in response to the test. The test showed that all toes were flexed when the digital tendons of the chicken were intact. All toes were flexed except the third toe after the flexor tendons of the third toe were transected. All toes were extended after all the digital flexor tendons were transected. All toes had no response after all the digital flexor and extensor tendons were transected.ConclusionsThe distal forearm squeeze test is valuable in examining digital flexor tendon injuries. If only the flexor digitorum profundus tendon is examined, the PIP joint of the finger should be stabilized in extension during the test.

An investigation of tendon strains in jersey finger injury load cases using a finite element neuromuscular human body model.

Introduction: A common hand injury in American football, rugby and basketball is the so-called jersey finger injury (JFI), in which an eccentric overextension of the distal interphalangeal joint leads to an avulsion of the connected musculus flexor digitorum profundus (FDP) tendon. In the field of automotive safety assessment, finite element (FE) neuromuscular human body models (NHBMs) have been validated and are employed to evaluate different injury types related to car crash scenarios. The goal of this study is to show, how such a model can be modified to assess JFIs by adapting the hand of an FE-NHBM for the computational analysis of tendon strains during a generalized JFI load case. Methods: A jersey finger injury criterion (JFIC) covering the injury mechanisms of tendon straining and avulsion was defined based on biomechanical experiments found in the literature. The hand of the Total Human Model for Safety (THUMS) version 3.0 was combined with the musculature of THUMS version 5.03 to create a model with appropriate finger mobility. Muscle routing paths of FDP and musculus flexor digitorum superficialis (FDS) as well as tendon material parameters were optimized using literature data. A simplified JFI load case was simulated as the gripping of a cylindrical rod with finger flexor activation levels between 0% and 100%, which was then retracted with the velocity of a sprinting college football player to forcefully open the closed hand. Results: The optimization of the muscle routing node positions and tendon material parameters yielded good results with minimum normalized mean absolute error values of 0.79% and 7.16% respectively. Tendon avulsion injuries were detected in the middle and little finger for muscle activation levels of 80% and above, while no tendon or muscle strain injuries of any kind occurred. Discussion: The presented work outlines the steps necessary to adapt the hand model of a FE-NHBM for the assessment of JFIs using a newly defined injury criterion called the JFIC. The injury assessment results are in good agreement with documented JFI symptoms. At the same time, the need to rethink commonly asserted paradigms concerning the choice of muscle material parameters is highlighted.

Encircling tendon repair site with collagen sheet in flexor zone 2: retrospective study

BackgroundPeritendinous adhesion is the most common complication of tendon repairs in the hand and often requires surgical intervention, resulting in increased labor loss and increased treatment costs. Many agents used to reduce tendon adhesion in animal models, however these agents have not entered clinical use. This study is the first-ever clinical study that evaluates encircling tendon repair site with collagen sheet as an anti-adhesion barrier.MethodsBetween December 2014 and January 2020, 156 patients included in this study, with clean cut isolated flexor digitorum profundus (FDP) tendon injury in flexor tendon zone 2. All tendons repaired with modified double Kessler technique. In 76 patients, tendon repair site encircled with collagen sheet. 80 patients were randomly selected from our clinical records and functional results are compared with Strickland’s total active motion grading system.ResultsThe mean total range of motion was 79% in the control group and 81% in the collagen sheet group, and there was no statistically significant difference between the two groups (Z: − 1.393, p = 0.164). In the control group, very good and good repair according to Strikland classification was 65/80 (81%). In the collagen sheet group, it was 62/76 (82%), respectively. There was statistically significant difference between 5 FDP TAM measurements between collagen sheet and control group (t(35) = 0.29, p = 0.016, p < 0.05). The mean TAM of the 5 FDP tendons in the collagen sheet group: 83.8 (SD: 8.2) in the and 76.1 (SD: 9.5) in the control group.ConclusionsFor the first time in the literature, functional results of Zone 2 flexor tendon repair using collagen sheets in patients with clean cut tendon injuries reported. However, there were no statistical difference about total active motion between control and collagen sheet group, 5th FDS tendon repairs encircled with collagen sheets had better outcomes. Prospective studies in patient groups with high adhesion risk are recommended.

Cyclic testing of six-strand suture techniques for zone 2 flexor tendon lacerations

BackgroundBiomechanical analysis using cyclic testing for repaired flexor tendons is a clinically relevant method. The aim of this study was to evaluate the tensile properties of two six-strand suture techniques, the triple looped suture and Yoshizu #1 suture techniques using cyclic testing under simulating early active mobilization conditions. MethodsTwenty-five flexor digitorum profundus tendons harvested from fresh frozen human cadaver hands were repaired in zone 2 utilizing one of three repair techniques: the 2-strand modified Kessler (MK) technique as a control, the triple looped suture (TLS) and Yoshizu #1 suture (Y1) techniques. In each suture technique, 4-0 monofilament nylon sutures were used for core sutures and 6-0 monofilament nylon sutures for circumferential running sutures. Cyclic testing was performed using 20 N with 600 cycles at 1 Hz. ResultsFive out of eight specimens in the MK group ruptured during cyclic testing. Thus, this group was excluded from analysis. On the other hand, all tendons in the TLS and Y1 groups tolerated cyclic testing. Average gaps of the TLS and Y1 groups were 0.5 ± 0.8 mm and 1.9 ± 2.2 mm, respectively. All tendons in the TLS group and six out of nine tendons in the Y1 group formed gaps less than 2 mm. Two tendons in the Y1 group formed a gap of 3.8 and 6.6 mm had breakage of peripheral sutures at the first cycle. Mean ultimate tensile force of the TLS and Y1 group measured after cyclic tensing, were 66.2 ± 9.0 N and 65.9 ± 13.1 N, respectively. No statistical difference between the two groups was found in gap and ultimate tensile forces. ConclusionsThis study suggested that the TLS and Y1 techniques have tensile properties to allow early active mobilization. None of tendons repaired with the TLS technique had gaps more than 2 mm.

Morphological, histological and biomechanical comparison of bone marrow aspirate concentrate, micro-fragmented adipose tissue and platelet-rich plasma in prevention of tendon adhesion

Flexor tendon repair often leads to peritendinous adhesions, reducing finger motion and hand function. This study compares the effects of stromal cells from different sources and platelet-rich plasma (PRP) on adhesion formation after tendon repair. Forty rabbits had their flexor digitorum profundus tendons transected and repaired with a modified Kessler suture technique. The control group received an isotonic solution. PRP, bone marrow aspirate concentrate (BMAC), and micro-fragmented adipose tissue (MFAT) were injected in groups 2, 3, and 4, respectively. Rabbits wore casts for 2 weeks. Assessments included morphology, histopathology, range of motion (ROM), and biomechanical testing at the 3rd and 8th weeks. At 3 weeks, the BMAC group had the thickest and longest adhesions, the highest Tang Score, and inflammation score. However, at 8 weeks, the BMAC group had the lowest Tang Score and inflammation score. ROM was higher in the PRP group at 3 weeks and BMAC group at 8 weeks. No significant differences were found between BMAC and MFAT groups in adhesion measurements. Biomechanical parameters were higher in BMAC and MFAT groups at 8 weeks compared to control. BMAC therapy after primary flexor tendon repair improves adhesion formation and maintains ROM. It also enhances the biomechanical properties of the flexor tendon during the later stages of healing.

Endoscopic Resection of Ulnar Bursa of the Palm: 2 Ulnar Portals Technique

Ulnar bursa of the hand invaginates the flexor digitorum superficialis and flexor digitorum profundus tendons of the little, ring, long, and index fingers. Distension of this bursa can have an inflammatory or infective cause. It can also originate from pathology of another site (e.g., degenerative wrist joint). Because of the tough overlying palmar aponeurosis, distended ulnar bursa can have swelling at a remote site. The distended ulnar bursa can also have compressive neuropathy to the ulnar nerve and median nerve. The purpose of this Technical Note is to describe the technical details of the 2 ulnar portals technique involving endoscopic resection of the ulnar bursa. This is indicated for symptomatic distension of the ulnar bursa, especially with hypothenar extension.

Une étude anatomique clinique de la zone de sécurité pour l’abord palmaire pour l’arthroscopie du poignet

ObjectiveThe current study was to perform an anatomical observation of the volar approach for wrist arthroscopy and to establish the safe zone for this approach. MethodsEight preserved specimens and 2 fresh specimens were used to simulate the medial-to-lateral operation and to mark the volar approach. Based on anatomical measurements of the volar approach, the closest distances from the half, 6R, 6U, VR, VR’ and VU approaches to the adjacent important structures were established. ResultsThe closest distance from the half approach to the superficial branch of the radial nerve was 2.4±1.5mm. The closest distances from the 6U and 6R approaches to the dorsal carpal branch of the ulnar nerve were 16.2±1.3mm and 9.0±2.4mm, respectively. The closest distances from the VR and VR’ approaches to the palmar cutaneous branch of the median nerve were 6.7±1.1mm and 2.8±0.9mm, respectively; the closest distances to the radial artery were 6.3±4.0mm and 10.0±3.4mm, respectively. Moreover, both of the two approaches passed through the base of the flexor carpi radialis tendon. The closest distance from the VU approach to the ulnar artery and flexor digitorum profundus tendon were 3.3±1.4mm and 0.3±2.5mm, respectively. ConclusionsIn conclusion, a safe zone could be located for the establishment of the volar approach for wrist arthroscopy. Level of evidenceIII; retrospective study with no control group.

Anomaly originated flexor digitorum superficialis muscle of the small finger: A case report.

We present a clinical case of flexor digitorum superficialis (FDS) muscle belly of the small finger originating from the palm of a patient undergoing carpal tunnel surgery with a literature review. A 28-year-old right-handed woman visited our hospital with a chief complaint of a continuous tingling sensation and weakness in the right hand, which began after the volar side of her wrist was crushed by a machine during work 2 weeks prior. The patient complained of a continuous tingling sensation in the thumb, index, and middle fingers. The patient had a positive result on Tinel test of the median nerve of the wrist. As electromyography and nerve conduction velocities showed signs of severe injury in the right median nerve, exploration and carpal tunnel release were planned. Carpal tunnel release was performed under regional anesthesia using the classical open approach. The median nerve in the distal forearm and distal portion of the flexor retinaculum appeared to be narrowed and compressed. An anomalous muscle originating from the flexor retinaculum is also observed. The FDS muscle of the small finger was excised at the flexor retinaculum and musculotendinous junction and sutured to the flexor digitorum profundus tendon. At the 37-month follow-up, the patient did not experience any tingling sensation or weakness. She showed excellent range of motion of the right small finger. The grip strength was 20 kg on both the right and left sides. Quick disabilities of the arm, shoulder, and hand score was 2.3. Asymptomatic small finger FDS muscle anomalies can occur, as demonstrated in this case study. Thus, physicians should familiarize themselves with small finger FDS muscle anomalies during interactions with patients to facilitate future treatments of patient complaints related to the hand, as well as wrist laceration or trauma requiring hand exploration.