Flexor Digitorum Profundus Tendon Research Articles

Does methylene blue reduce adhesion during the healing process after tendon repair?

Objectives This study aims to biomechanically and histopathologically investigate the effects of methylene blue (MB) on preventing postoperative adhesion in chickens undergoing full- thickness flexor tendon incision.Materials and methods This study was performed between June 2017 and June 2018 on Hubbard JA 57 type chickens (age, 6 months; weight, 2.2±0.3 kg). Sixty-four tendons were studied in 32 chickens, including 16 in the control group and 16 in the experimental group. The second and third finger flexor digitorum profundus tendons of the left foot of each chicken were repaired primarily after a full-thickness incision approximately 1 cm proximal to the distal adhesion area. In the control (n=32) and experimental groups (n=32), 0.25 mL of normal saline and 0.25 mL of 1% MB solutions were applied locally to the surgical site, respectively. The operated limb was immobilized using a circular cast. 16 chickens were randomly selected in each group and examined at the fourth week, and the remaining 16 chickens were examined at the sixth week. Thirty-two of these tendons were evaluated using the Tang histopathological adhesion classification system, and the other 32 were evaluated with a biomechanical pull system.Results Adhesion was found to be less in the experimental group compared to the control group at the end of the fourth and sixth weeks both histopathologically and biomechanically. Furthermore, adhesion was significantly less in the experimental group at the end of the sixth week compared to the fourth week both histopathologically and biomechanically.ConclusionHistopathological and biomechanical results show that MB, which has anti-inflammatory, antiseptic, antimicrobial and antioxidant effects, reduces adhesion during the healing process after tendon repair. We think that local MB application, particularly in surgeries performed after this type of injury, will be beneficial on early rehabilitation and functional results.

Flexor digitorum profundus with or without flexor digitorum superficialis tendon repair in acute Zone 2B injuries.

A total of 53 patients with complete cuts of two flexor tendons in Zone 2B treated over a 9-year period was reviewed. Twenty-three patients (28 fingers) had only flexor digitorum profundus repair, while 30 patients (36 fingers) had both flexor digitorum profundus and flexor digitorum superficialis repairs, with a mean follow-up of 21 months (range 12-84). The decision to repair the flexor digitorum superficialis was made according to intraoperative judgement of ease of repair and gliding of the flexor digitorum profundus tendon. Two groups of patients showed no significant differences in total range of active or passive digital motion and power grip percentage to the contralateral hand. However, the values of power grip were statistically superior in the patients with both tendons repaired. The patients after flexor digitorum profundus-only repairs showed significantly greater but still mild flexion contracture (mean 20 °) of the operated digits. The Tang gradings were the same with 89% good and excellent rates in both groups. The conclusion is that although repair of both flexor digitorum profundus and flexor digitorum superficialis tendons is slightly more preferable based on increased grip strength, the repair of the flexor digitorum superficialis together with flexor digitorum profundus is not mandatory. Whether or not to repair flexor digitorum superficialis is an intraoperative decision based on the ease of gliding of the repaired tendon(s).Level of evidence: III.

An investigation into the reliability and methodology of the Linburg-Comstock anomaly clinical test

Study DesignThis is a cross-sectional study. IntroductionAn intertendinous connection between the flexor pollicis longus (FPL) and index flexor digitorum profundus (IFDP) tendons causes involuntary index flexion during active thumb flexion and has been named the Linburg-Comstock anomaly (LCA). It may become symptomatic or cause functional limitations. Literature has documented the prevalence to range from 13% to 70%. Cadaver studies have reported an anatomical connection in 5% to 25%. PurposeThis study aimed to examine the methodology and reliability of the LCA clinical diagnostic test and to explore the wide range of reported incidence and the discrepancy between cadaver and subject prevalence. MethodsTwo examiners observed for the presence of involuntary index flexion during 3 separate variations of thumb flexion in 67 subjects (134 limbs); results were considered positive if involuntary flexion occurred at either index interphalangeal joint. Intertester reliability was assessed using Cohen's kappa coefficient. The volar forearm and wrist of 53 cadavers (106 limbs) were dissected and assessed for an observable and mechanical tendinous connection between the FPL and IFDP tendons. ResultsPrevalence for subjects (5%-32%) was at the lower end of the range of previously reported values; results differed with altering thumb flexion motion. Observation for the presence of an intertendinous connection between the FPL and IFDP tendons in cadaver specimens (23%) fell within previously reported ranges. Intertester reliability coefficients ranged from no to weak agreement and varied according to specific thumb flexion motion performed during the test. ConclusionsThe identification of index finger flexion during thumb flexion varied both with thumb flexion motions and with whether flexion was assessed at the index proximal interphalangeal or distal interphalangeal joint. Intertester reliability was low for all variations of the LCA clinical test performed. The wide range in previously reported LCA incidence may be due to variability in testing procedure, and there is a need to establish a reliable and valid clinical test for this potentially symptomatic anatomic anomaly.

Transcriptome profiling of digital flexor tendons after injury in a chicken model.

Background: Modulation of tendon healing remains a challenge because of our limited understanding of the tendon repair process. Therefore, we performed the present study to provide a global perspective of the gene expression profiles of tendons after injury and identify the molecular signals driving the tendon repair process.Results: The gene expression profiles of flexor digitorum profundus tendons in a chicken model were assayed on day 3, weeks 1, 2, 4, and 6 after injury using the Affymetrix microarray system. Principal component analysis (PCA) and hierarchical cluster analysis of the differentially expressed genes showed three distinct clusters corresponding to different phases of the tendon healing period. Gene ontology (GO) analysis identified regulation of cell proliferation and cell adhesion as the most enriched biological processes. Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis revealed that the cytokine–cytokine receptor interaction and extracellular matrix (ECM)–receptor interaction pathways were the most impacted. Weighted gene co-expression network analysis (WGCNA) demonstrated four distinct patterns of gene expressions during tendon healing. Cell adhesion and ECM activities were mainly associated with genes with drastic increase in expression 6 weeks after injury. The protein–protein interaction (PPI) networks were constructed to identify the key signaling pathways and hub genes involved.Conclusions: The comprehensive analysis of the biological functions and interactions of the genes differentially expressed during tendon healing provides a valuable resource to understand the molecular mechanisms underlying tendon healing and to predict regulatory targets for the genetic engineering of tendon repair.Tendon healing, Adhesion, Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, Weighted Gene Co-expression Network Analysis, Protein–protein Interaction

Treatment of tendinous mallet finger deformity with a part of the flexor digitorum profundus tendon.

To introduce and evaluate an updated surgical technique for the treatment of tendinous mallet finger deformity. From April 2017 to September 2018, 13 cases of tendinous mallet finger deformity were treated. All patients had zone I extensor tendon rupture, with no residual tendon at the insertion for suture, and no avulsion fracture in the distal phalanx. Extensor tendon insertion reconstruction was realized by suturing the transferred portion of the flexor digitorum profundus tendon with the proximal end of the extensor tendon via a constructed bone tunnel. The treatment efficacy of the enrolled patients was evaluated by using Dargan evaluation criteria post-operatively. All patients were followed up with an average duration of 10.6 months. At the last follow-up, 12 patients showed excellent function recovery and one case had unsatisfactory outcome according to the Dargan evaluation criteria. Satisfactory therapeutic outcome for the treatment of tendinous mallet finger deformity can be achieved by reconstructing extensor tendon insertion using a part of the flexor digitorum profundus tendon, implying that the proposed treatment method is worthy of clinical application.

Ultrasound-Guided Non-radio Opaque Symptomatic Foreign Body Removal

This is a case of a 20-year-old lady presenting in surgical OPD with history of trauma 1 year ago with foreign body in situ in the right distal forearm where she had history of unsuccessful attempt of surgery for foreign body removal at the time of injury. She was investigated with ultrasonography of local part which suggested thorn within the tendon of flexor group of muscles. Thorn removal was performed with ultrasonography guidance under brachial block. Thorn was found to be completely within the tendon of flexor digitorum profundus with close vicinity to ulnar artery. The surgery was performed on day-care basis without intraoperative or postoperative complication, and she was discharged with utmost satisfaction on the same evening.

Outcomes After Flexor Tendon Injuries in the Pediatric Population: A 10-Year Retrospective Review.

Background: Pediatric outcomes after flexor tendon repairs are variable, and evidence in the literature remains scarce. Methods: Repair of pediatric flexor tendon injuries was reviewed over a 10-year period (2005-2015). Data collection consisted of patient demographics, injury characteristics, anesthetic choice, repair technique, rehabilitation protocol, American Society for Surgery of the Hand Total Active Motion (TAM) scores, and complications. Results: There were 109 patients included in our study, with a total of 162 digits injured and 235 flexor tendon injuries. The mean age was 12 ± 4.6 years. The small finger (48 of 162; 30%) and the flexor digitorum profundus tendon (126 of 235) were the most commonly injured. The mechanism of injury was mainly from a knife (46 of 109; 42.2%) in zone II (82 of 159; 52%). Injuries were mostly repaired under general anesthetic (61 of 104; 56%). The Kessler technique was the predominant repair mechanism (111 of 225 repairs; 49%). Most patients (103 of 109; 95%) had excellent or good TAM scores with 5 postoperative ruptures reported. The most common complication was stiffness (17 of 121 complications; 14%), with most patients having no complications ( 74 of 109 patients; 68%). Patients were commonly immobilized (mean 8.4 ± 10.3 weeks) with a splint (93 of 109; 85%). There were 85 patients who followed a postoperative rehabilitation protocol for 12 ± 18 weeks. Patient demographics, time of repair, injury characteristics, anesthetic choice, and rehabilitation protocol were not significantly correlated with TAM scores or complication rates. Conclusions: Pediatric tendon injuries have good outcomes with no predictive factors identified. Surgical repairs performed under local anesthetic have similar outcomes without increased rates of complications, but remain underused in the pediatric population.

Zone 2 Flexor Tendon Repair Location and Risk of Catching on the A2 Pulley

To determine the region of the flexor digitorum profundus (FDP) and flexor digitorum superficialis (FDS) tendons in zone 2 that, when involved by a laceration repair, will reliably catch on the A2 pulley after surgery. Using fresh-frozen cadavers (5 hands, 20 digits), excursions of the FDP and FDS tendons were measured in relation to the A2 pulley. The C1, A3, and C2 pulleys were resected. The digit was maximally flexed by applying traction to the flexor tendon in the forearm. An 8-0 suture tag was placed in the flexor tendons immediately distal to the A2 pulley. The digit was then passively fully extended to measure tendon excursion. Measurements were repeated with 50% venting and 100% release of the A4 pulley. Reference points such as tendon insertions and flexion creases were obtained. This protocol was repeated sequentially for the index, middle, ring, and little fingers. For all 20 fingers, the suture placed into the FDP just distal to the A2 pulley with the finger fully flexed traveled 1.6 ± 1.9 mm distal to the proximal edge of the A4 pulley with passive extension of the finger. The mean excursion for the FDP was 24.6 ± 3.2 mm, and 16.9 ± 3.1 mm for the FDS. The mean A2 pulley length was 16.2 ± 3.5 mm, and the mean distance between the distal edge of the A2 pulley and the proximal edge of the A4 pulley was 23.0 ± 3.3 mm. Venting the A4 pulley 50% and 100% increased FDP excursion a maximum of 0.9 and 1.9 mm, respectively. An FDP repair proximal to the A4 pulley will slide under the A2 pulley with full active digital flexion after surgery. If the distal FDP stump lies underneath the A4 pulley with the digit fully extended, the FDP repair will not likely engage the A2 pulley with full flexion after surgery. The FDP excursion can be reliably predicted as a percentage of the A2 (distal) to the A4 (distal) pulley distance. Most importantly, the distance between the repair site and the A4 pulley approximately equals the length of the A2 pulley that requires release to avoid postoperative triggering. Knowledge of this high-risk region of flexor tendon repair will guide surgeons regarding the potential need for partial release of the A2 pulley.

Assessment of fixation for anterior cruciate ligament reconstruction using oversized suspensory devices on full-length femoral tunnels

BackgroundIn ACL repair, full-length single-diameter tunnels facilitate anatomic femoral fixation with suspensory devices, especially with outside-in techniques, and are required after accidental cortical perforation. With tunnel diameters over 6 mm, fixation resistance using regular suspensory devices may not suffice. Oversized cortical footprint devices could be a solution to guarantee fixation performance in larger tunnel diameters. This study aims to assess the biomechanical properties of ACL femoral fixation provided by two enlarged suspensory devices of similar characteristics, a fixed loop (G-Lok™ with G-Lok-XL™) and an adjustable loop (ProCinch™ with G-Lok-XL™), resting on a full-length 9 mm diameter tunnel compared to the widely accepted regular fixed-loop device (G-Lok™) on a socket tunnel. MethodsTwenty-seven fresh frozen porcine femurs and flexor digitorum profundus tendons were randomly assigned to a study group depending on the fixation method used (N = 9). Graft-femur constructs were subjected to a traction cyclic test (5000 cycles, [50–250]N load, 1 Hz) followed by a load-to-failure test (v = 1 mm/s). Residual displacement during the cyclic test and stiffness, displacements at physiological loads, ultimate load and corresponding displacement during the load-to-failure test were determined. FindingsNo significant differences could be established for any parameter measured in the comparison between the control with the socket tunnel and the oversized fixations with full-length tunnels. InterpretationACL femoral fixation achieved in full-length single diameter tunnels by using an enlarged suspension device, both with a fixed or an adjustable loop, provide similar biomechanical properties to the gold-standard fixed-loop device in a socket tunnel. Therefore, its clinical use may be safe.

Flexor Tendon Grafting Using Extrasynovial Tendons Followed by Early Active Mobilization

PurposeThis study evaluated the outcomes of early active mobilization after flexor tendon grafts using extrasynovial tendons with a novel distal fixation technique.MethodsThis study was a retrospective case series. The flexor digitorum profundus (FDP) tendons of 7 digits in 7 patients were reconstructed with extrasynovial tendons, which included the palmaris longs, plantaris, and extensor digitorum longus, in a single- or 2-stage procedure between 2008 and 2017. Of the 7 patients, 6 were male and the average patient age was 48 years. The injuries involved 2 middle, 2 ring, and 3 little fingers. The tendons were sutured into the appropriate FDP tendon proximally using end-weave anastomosis; the distal end of the graft was fixed to the distal stump of the FDP using an interlacing suture or a small bone anchor combined with the pull-through technique. The digits were mobilized with a combination of active extension and passive and active flexion in a protective orthosis during the first 6 weeks after surgery. Average follow-up was 18 months. We measured active and passive digit motion both before tendon grafting and at the final evaluation. Outcomes were graded by the LaSalle formula to assess staged flexor tendon reconstruction.ResultsAverage passive range of motion (ROM) of the proximal and distal interphalangeal joints before flexor tendon grafting was 146° (SD, 22°). Mean active ROM of these joints at the final evaluation was 123° (SD, 34°). Using the LaSalle formula, mean recovery of active motion was 83%. We encountered no grafted tendon rupture and no finger required tenolysis.ConclusionsOur proximal and distal fixation techniques allowed the autologous extrasynovial tendon grafts to withstand the stress encountered during early active mobilization with good postoperative ROM and minimal complications.Type of study/level of evidenceTherapeutic I.

Atypical osteochondroma of the hamate that presented clinically as carpal tunnel syndrome: report of an extremely rare case and literature review

BackgroundOsteochondroma is a benign tumor that occurs mainly at the metaphysis of long bones and seldom arises from carpal bones. We describe an extremely rare case of osteochondroma of the hamate without a typical cartilaginous cap and with a spiky bony protrusion in an elderly patient.Case presentationA 78-year-old right-handed female housekeeper had a multilobed osteochondroma of the hamate, which caused carpal tunnel syndrome and irritation of the flexor tendons. Radiological examinations showed a morphological abnormality of the hamate comprising a spiky bony protrusion into the carpal tunnel and a free body proximal to the pisiform. Open carpal tunnel release and resection of the spiky bony protrusion on the hook of the hamate were performed. The flexor digitorum profundus tendons of the ring and little fingers displayed synovitis and partial laceration in the carpal tunnel. Histological examination also showed atypical findings: only a few regions of cartilaginous tissue were seen in the spiky bony protrusion, whereas the free body proximal to the pisiform contained thick cartilaginous tissue such as a cartilaginous cap typical of osteochondroma. We speculated that the bony protrusion to the carpal tunnel had been eroded by mechanical irritation caused by gliding of the flexor tendon and had resulted in the protruding spiky shape with less cartilaginous tissue. The fractured cartilaginous cap had moved into the cavity within the carpal tunnel proximal to the pisiform and had become a large free body.ConclusionsOsteochondroma of the carpal bone may take various shapes because the carpal bone is surrounded by neighboring bones and tight ligaments, which can restrict tumor growth. This type of tumor is likely to present with various symptoms because of the close proximity of important structures including nerves, tendons, and joints. The diagnosis of osteochondroma of the carpal bone may be difficult because of its rarity and atypical radiological and histological findings, such as the lack of a round cartilaginous cap. We suggest that surgeons should have a detailed understanding of this condition and should make a definitive diagnosis based on the overall findings.

Biomechanical Analysis of Zone 2 Flexor Tendon Repair With a Coupler Device Versus Locking Cruciate Core Suture

To compare flexor tendon repair strength and speed between a tendon coupler and a standard-core suture in a cadaver model. In 5 matched-pair fresh cadaver hands, we cut the flexor digitorum profundus tendon of each finger in zone 2 and assigned 20 tendons to both the coupler and the suture groups. Coupler repair was with low-profile stainless steel staple plates in each tendon stump, bridged by polyethylene thread. Suture repair was performed using an 8-strand locking-cruciate technique with 4-0 looped, multifilament, polyamide suture. One surgeon with the Subspecialty Certificate in Surgery of the Hand performed all repairs. Via a load generator, each flexor digitorum profundus was loaded at 5 to 10 N and cycled through flexion just short of tip-to-palm and full extension at 0.2 Hz for 2,000 cycles to simulate 6 weeks of rehabilitation. We recorded repair gapping at predetermined cycle intervals. Our primary outcome was repair gapping at 2,000 cycles. Tendons that had not catastrophically failed by 2,000 cycles were loaded to failure on a servohydraulic frame at 1 mm/s. Tendon repair gapping was similar between coupled and sutured tendons at 2,000 cycles. Tendons repaired with the coupler had higher residual load to failure than sutured tendons. Mean coupler repair time was 4 times faster than suture repair. Zone 2 flexor repair with a coupler withstood simulated early active motion in fresh cadavers. Residual load to failure and repair speed were better with the coupler. This tendon coupler may eventually be an option for strong, reproducible, rapid flexor tendon repair.

Idiopathic Carpal Spasm (Trousseau’s Sign) After Intraoperative Arm Tourniquet Inflation in an Intubated Patient

We present a case of a 38-year-old male who sustained a laceration from a knife to the volar aspect of his left index and middle fingers. He had clinical injury to his flexor digitorum profundus tendons to both digits. He underwent operative exploration and repair of the tendons under general anaesthetic. An arm tourniquet was inflated to allow for haemostasis in the operative field. A few minutes after inflation, the patient’s hand went into carpal spasm. The tourniquet was deflated and the spasm resolved. Intraoperative serum calcium and carbon dioxide levels were normal. The operation proceeded with the tourniquet deflated. Postoperatively serum calcium and magnesium levels were within normal limits, as was serum vitamin D and parathyroid hormone levels. It has been reported that carpal spasm can occur with tourniquet use in the anxious patient due to hyperventilation and resultant metabolic alkalosis. This however is the first reported case of carpal spasm in the setting of tourniquet use and normal serum electrolytes and respiratory parameters in an intubated patient.

Mini-Plate and Screw Fixation Technique for Comminuted Flexor Digitorum Profundus Avulsion Fracture

Avulsion fracture of flexor digitorum profundus (FDP) tendon is relatively rare fracture at the distal phalangeal base than avulsion fracture of terminal extensor tendon. Terminal extensor avulsion fracture, known as bony mallet finger, could be successfully treated by closed reduction and pinning, such as extension block technique. However, most of FDP avulsion fracture, known as Jersey’s finger, needed open reduction, because of the proximal migration of fracture fragment and difficulty of pin fixation. Up to date, most of FDP avulsion fractures were treated by open reduction and fixation by pull-out suture or suture anchor technique. We report a case of comminuted FDP avulsion fracture, successfully treated by open reduction and mini-plate and screw fixation technique.

Evaluation of Hand Tendon Movement by Using High-Frequency Ultrasound Vector Doppler Imaging.

Injuries to the hands, wrists, and fingers often involve damage to the tendons. The ability to measure tendon movements during the rehabilitation process can provide clinicians with important information in the quantification of tendon injuries. Conventionally, the tendon is considered a single spring-like structure during force transmission, and its twisted structure is neglected. Recently, clinicians believed that the twisted fiber structure (which enables tendon rotation during movement) of the tendon can provide it with a degree of elasticity and improve the efficiency of force transmission. However, observation of the hand tendon rotation in vivo by using the current imaging modalities is difficult. In this study, a 40-MHz high-frequency vector Doppler imaging (HFVDI) was used to visualize the movement of the hand tendon during muscle contraction. The performance of HFVDI was verified using a rotation phantom experiment. Two human experiments were designed in the present study: 1) participants were allowed to bend their distal and proximal interphalangeal (DIP and PIP) joints of fingers freely and 2) the PIP joint of the finger was fixed such that only the DIP could be moved. The HFVDIs of the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) tendons were obtained in the transverse and longitudinal views to observe the movements of the hand tendon during finger movements. The average longitudinal displacements of the FDS and FDP were approximately 3-4mm for free bending of the finger; however, it was reduced when only the DIP was moved. The rotational phenomenon of the FDS and FDP tendons was observed in the transverse view, which demonstrated the different rotational behaviors of the FDS and FDP fibers during muscle contraction. All the results validated the potential of HFVDI as a novel tool for visualizing tendon rotation and would be useful in providing quantitative information regarding tendon function to determine the rehabilitation process following injuries.

Tendon With Z-Lengthening Technique and Construct Assessment: A Biomechanical Study for Use in Tendon Reconstructions

Tendon reconstruction is frequently required under conditions of tendon deficiency. The authors sought a technique that could obviate the need for tendon harvest yet meet the minimum load of 45 N required for an early active motion protocol. This study was designed to determine the ideal suture construct utilizing the tendon with Z-lengthening (TWZL) technique. Sixty fresh-frozen cadaveric flexor digitorum profundus tendons of the index, middle, and ring fingers were randomized into 5 different TWZL construct designs using 3-0 braided polyethylene suture. Constructs were tested on an electromechanical actuator until failure was observed on the load-elongation recording. Data points on maximum yield and load at 8% strain were recorded for each construct. The maximum yield data revealed the construct with a 4-core suture type configuration (construct #4) had the highest overall mean load to failure at 150 N compared with all other constructs. The construct with the highest mean load at 8% strain was that with a 4-core type repair (construct #4) at 59 N. The constructs with Krackow locking sutures (constructs #2, #3, and #4 were found to withstand a significantly higher mean load at 8% strain than those without Krackow sutures (#0 and #1). Comparison among constructs with Krackow locking sutures #2 (56 N), #3 (48 N), and #4 (59 N) did not show a significant difference in mean load at 8% strain. Construct #3, however, had an SD and 95% confidence interval that fell below the 45 N early active motion threshold, whereas both #2 and #4 had 95% confidence intervals that fell no lower than 50 N. This study provides evidence that the TWZL technique utilizing either construct #2 or #4 could provide sufficient strength and reproducibility for tendon reconstruction. The study describes the application of the TWZL technique for utilization in tendonreconstruction and quantifies differences in the yield strengths of the 5 proposed constructs.

Tenodesis Effect Mimicked by Flexor Tendon Entrapment in a Paediatric Midshaft Forearm Fracture: a Case Report and Review of the Literature

Entrapment of the flexor digitorum profundus (FDP) tendon following radius and ulna midshaft paediatric forearm fractures has been reported rarely in the literature. To date, 19 cases have been described. A characteristic fracture pattern, persistent cortical defect at the fracture site and flexion contracture not responsive to hand therapy are all hallmarks of the condition. We present a case along with a review of the literature. A 12-year-old boy underwent exploration of a primary right open radius and ulna fracture site 22 months following initial open reduction and titanium elastic nail system (TENS) fixation. The little finger FDP tendon was found interposed between the ulna bone with a significant defect in the cortical surface of the ulna, correlating with a lucency identified on plain radiograph preoperatively. Removal of all interposed tissue, debridement of the bone edges and Pulvertaft tendon weave of the FDP of the little finger to the ring finger were performed. The patient recovered full upper limb function. Clinicians should be vigilant to identify this complication when managing patients with forearm fractures. A thorough clinical examination pre– and post–open or closed forearm fracture reduction should be performed to ensure early recognition of this rare complication. If the tenodesis effect and post-operative adhesions cannot be adequately released by therapy, interposition of the tendon at the fracture site should be considered as a differential diagnosis. If the complication is suspected, early operative intervention should be performed to ensure optimal fracture healing and restoration of function.

Avulsion Injuries of the Hand and Wrist.

Injuries of the hand and wrist are frequently encountered in radiology. Avulsions of the hand and wrist are a heterogeneous group of injuries, but they often have a characteristic imaging appearance that relates to the intricate bone and soft-tissue anatomy and the mechanism of injury. The imaging appearance and this intricate form and function dictate treatment of hand and wrist avulsions. This article reviews frequently and infrequently encountered avulsion injuries and describes abnormalities that may mimic the imaging appearance of avulsions. Specifically discussed entities include the Bennett and reverse Bennett fracture, ulnar collateral ligament avulsion, radial and ulnar styloid process avulsion, triquetral avulsion, mallet and jersey finger, central slip avulsion, and acute and chronic volar plate avulsion injuries. Uncommon avulsion injuries are also described and include avulsions of the scapholunate ligament, extensor carpi radialis longus and brevis tendons, trapeziometacarpal ligament, radial collateral ligament, and flexor digitorum profundus tendon. Emphasis is placed on the relevant anatomy and typical imaging findings for each diagnosis, with pertinent clinical history, pathophysiologic evaluation, and treatment discussed briefly. Understanding the anatomy and expected imaging findings can aid the radiologist in recognizing and characterizing these injuries.©RSNA, 2020.

A1 pulley stretching treats trigger finger: A1 pulley luminal region under digital flexor tendon traction

BackgroundA1 pulley stretching is recognized as a clinically beneficial treatment for trigger finger. It is thought to lead to an increase in the cross-sectional area of the A1 pulley luminal region, thus improving trigger finger symptoms. The purpose of the present study was thus to evaluate the resultant forces during stretching that increase the CSA of the A1 pulley luminal region using fresh-frozen cadavers. MethodsUsing seven fingers from three fresh-frozen cadavers to replicate A1 pulley stretching, we investigated the resultant forces during stretching that increase the cross-sectional area of the A1 pulley luminal region. The traction forces of the flexor digitorum profundus tendons were increased in steps to 150 N, and the cross-sectional area and height of the A1 pulley luminal region were measured using ultrasonography. FindingsThe cross-sectional area of the A1 pulley luminal region increased with step-wise increases in the flexor digitorum profundus traction. On average, the cross-sectional area and height of the A1 pulley luminal region showed increases of 31.4% and 43.6%, respectively, compared to the unloaded condition. InterpretationThese results confirmed that A1 pulley stretching increases the cross-sectional area of the A1 pulley luminal region. A1 pulley stretching has the potential to reduce the severity of trigger finger in patients facing surgery.

Outcomes of 200 digital flexor tendon repairs using updated protocols and 30 repairs using an old protocol: experience over 7 years.

We reviewed outcomes of 230 flexor tendon repairs in 27 thumbs and 203 fingers in Zone 1 and 2 over 7 years. In 2013, we used a 2-strand modified Kessler method followed by passive motion exercise in repairing flexor digitorum profundus tendon injuries in Zone 2 in 30 fingers; 24 fingers were followed, five (26%) had repair ruptures. Between 2014 and 2017, we used a 4- or 6-strand method to repair 111 flexor digitorum profundus tendons in Zone 2, followed by true early active motion. Two had repair ruptures. Among 101 fingers followed over 6 months, two fingers had tenolysis and 87 (87%) good or excellent outcomes. In 2018 to 2019, we used a 6-strand method to repair 42 flexor digitorum profundus tendons in Zone 2 with out-of-splint early active motion. None had repair ruptures or tenolysis. From 2014 to 2019, 27 flexor pollicis longus tendons were repaired in Zone 1 or 2, and 20 fingers had end-to-end flexor digitorum profundus repairs in Zone 1; none had repair ruptures or tenolysis. We conclude that a strong repair and true active motion are necessary for best outcomes of flexor tendon repairs in the thumb and fingers, and out-of-splint true active motion is safe.