The Three-Dimensional Relationship of the Axes of the Capitate and Third Metacarpal.

PURPOSE: We quantified the morphology and angulation of the third metacarpal (MC3) relative to the capitate using three-dimensional computed tomography data to inform surgical procedures such as total wrist arthroplasty and wrist arthrodesis. Specifically, we report the three-dimensional location of the intersections of the long axis of MC3 axis with the capitate cortical surface, the sagittal and coronal angles between the MC3 and capitate axes, and the MC3 shaft angle in the sagittal plane. We tested the hypothesis that these metrics did not differ between women and men. METHODS: Three-dimensional bone models of the capitate and MC3 were analyzed in 130 subjects (61M and 69F). Long axes of the MC3 and capitate were computed. The intersection of the metacarpal long axis with the cortical surface of the capitate, the angle between the metacarpal-capitate axes, and metacarpal shaft angle were calculated and compared between men and women. RESULTS: The long axis of the MC3 intersected the capitate at two locations on the outer cortical surface of the capitate. The proximal intersection was located near the midportion of the capitate, whereas the distal intersection was typically located within the capitate-MC3 articulation. The angle between the axes of the capitate and MC3 in the sagittal plane was a mean of 15°, ranging from 5° to 23°. The mean sagittal MC3 shaft angle was 166° and ranged from 158° to 173°.There were only subtle differences in these metrics between the sexes. CONCLUSIONS: The long axis of the MC3 penetrates the dorsal surface of the capitate about its midportion, but there is notable variation in this location as well as in the angular relationships. CLINICAL RELEVANCE: Three-dimensional measurements of the relationships between the third metacarpal and the capitate may serve as an important reference for the placement of intramedullary wires, plates, devices, and prosthetics.

One-Year Outcomes of the Anatomical Front and Back Reconstruction for Scapholunate Dissociation.

PURPOSE: Anatomical front and back (ANAFAB) reconstruction addresses the critical volar and dorsal ligaments associated with scapholunate dissociation. We hypothesized that patients with symptomatic, chronic, late-stage scapholunate dissociation would demonstrate improvements in all radiographic parameters and patient-reported outcomes (PROMs) after ANAFAB reconstruction. METHODS: From 2018 to 2021, 21 ANAFAB reconstructions performed by a single surgeon were followed prospectively, with 20 patients having a minimum follow-up of 12 months. In total, 17 men and four women were included, with an average age of 49 years. Three patients had modified Garcia-Elias stage 3 disease, eight stage 4, seven stage 5, and three stage 7. ANAFAB reconstruction of intrinsic and extrinsic ligament stabilizers was performed using a hybrid synthetic tape/tendon graft in a transosseous reconstruction. Pre- and postoperative radiographic parameters, grip, pinch strength, the Patient-Rated Wrist Evaluation, PROMIS Upper Extremity Function, and PROMIS Pain Interference outcome measures were compared. RESULTS: Mean follow-up was 17.9 months (range: 12-38). Radiographic parameters were improved at follow-up, including the following: scapholunate angle (mean 75.3° preoperatively to 69.2°), scapholunate gap (5.9-4.2 mm), dorsal scaphoid translation (1.2-0.2 mm), and radiolunate angle (13.5° to 1.8°). Mean Patient-Rated Wrist Evaluation scores for pain and function decreased from 40.6 before surgery to 10.4. We were unable to detect a significant difference in grip or pinch strength or radioscaphoid angle with the numbers tested. There were two minor complications, and two complications required re-operations, one patient who was converted to a proximal row carpectomy for failure of fixation, and one who required tenolysis/arthrolysis for arthrofibrosis. CONCLUSIONS: At 17.9-month average follow-up, radiographic and patient-reported outcome parameters improved after reconstruction of the critical dorsal and volar ligament stabilizers of the proximal carpal row with the ANAFAB technique. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

The effect of intravenous tranexamic acid on visual clarity in arthroscopic shoulder surgery compared to epinephrine and a placebo: a double-blinded, randomized controlled trial.

BACKGROUND: The addition of epinephrine in irrigation fluid and the intravenous or local administration of tranexamic acid have independently been reported to decrease bleeding, thereby improving surgeons' visualization during arthroscopic shoulder procedures. No study has compared the effect of intravenous tranexamic acid, epinephrine in the irrigation fluid, or the combination of both tranexamic acid and epinephrine on visual clarity during shoulder arthroscopy with a placebo group. We hypothesized that intravenous tranexamic acid is more effective than epinephrine mixed in the irrigation fluid in improving visualization during shoulder arthroscopy, with no additive effect when both are used. METHODS: Patients aged ≥18 years undergoing shoulder arthroscopy were randomized into one of 4 study arms: (1) saline irrigation fluid (placebo); (2) epinephrine (0.33 mL of 1:1000 per liter) mixed in irrigation fluid (EPI); (3) 1 g intravenous tranexamic acid (TXA); and (4) epinephrine and tranexamic acid combined (TXA + EPI). Visualization was rated intraoperatively on a scale from 0, indicating poor clarity, to 3, indicating excellent clarity, every 15 minutes and overall. The primary outcome measure was the overall rating of visualization. A stepwise linear regression was performed using visualization as the dependent variable and independent variables including presence or absence of epinephrine and tranexamic acid, surgery duration, complexity, mean arterial pressure, increase in pump pressure, and volume of irrigation fluid. RESULTS: One hundred twenty-eight patients (mean age 56 years) were randomized. Mean visual clarity for the placebo, TXA, EPI, and TXA + EPI groups were 2.0 (±0.6), 2.0 (±0.6), 2.6 (±0.5), and 2.7 (±0.5), respectively (P < .001). The presence or absence of epinephrine was the most significant predictor of visual clarity (P < .001). Tranexamic acid presence or absence had no effect. No adverse events were recorded in any of the groups. CONCLUSION: Intravenous tranexamic acid is not an effective alternative to epinephrine in irrigation fluid to improve visualization during routine arthroscopic shoulder surgeries, and there is no additive effect when both are used.

Scapholunate Instability: Diagnosis and Management - Classification and Treatment Considerations - Part 2.

Intervention for scapholunate instability is aimed at halting the degenerative process by restoring ligament integrity and normalizing carpal kinematics. Part 1 of this Current Concepts article reviewed the anatomy, kinematics, and biomechanical properties of the scapholunate ligament as well as its critical stabilizers. In this section, we provide a foundation for understanding the spectrum of scapholunate ligament instability and incorporate meaningful new anatomical insights that influence treatment considerations. These updates clarify the importance of the critical stabilizers of the scapholunate interval, ligament-specific considerations in scapholunate ligament reconstruction, and the risks of ligament disinsertion when surgically exposing the dorsal wrist. We propose a ligament-based treatment algorithm based on the stage of injury, degree and nature of ligament damage, and presence of arthritic changes.

Scapholunate Instability: Diagnosis and Management - Anatomy, Kinematics, and Clinical Assessment - Part I.

Injuries to the scapholunate joint are the most frequent cause of carpal instability. The sequelae of these injuries account for considerable morbidity, and if left untreated, may lead to scapholunate advanced collapse and progressive deterioration of the carpus. Rupture of the scapholunate interosseous ligament and its critical stabilizers causes dyssynchronous motion between the scaphoid and lunate. Additional ligament injury or attenuation leads to rotary subluxation of the scaphoid and increased scapholunate gap. Intervention for scapholunate instability is aimed at halting the degenerative process by restoring ligament integrity and normalizing carpal kinematics. In the first section of this review, we discuss the anatomy, kinematics, and biomechanical properties of the scapholunate ligament as well as its critical ligament stabilizers. We provide a foundation for understanding the spectrum of scapholunate ligament instability and incorporate meaningful new anatomical insights that influence treatment considerations. The purpose is to provide an update regarding the anatomy of the scapholunate ligament complex, importance of the critical ligament stabilizers of the proximal carpal row, introduction of safe technique to surgically expose the scaphoid and lunate, as well as pathoanatomy as it pertains to the treatment of scapholunate dissociation. In the second section of this review, we propose a novel ligament-based treatment algorithm based on the stage of injury, degree and nature of ligament damage, and presence of arthritic changes.

Outcome of Tendon Transfer for Monomelic Amyotrophy (Hirayama Disease).

Hirayama disease is a motor neuron disease predominantly affecting adolescent males. The identifying feature of Hirayama disease is unilateral forearm and intrinsic muscle weakness that spares the brachioradialis, termed "oblique atrophy." Hirayama disease progresses slowly over several years, followed by an abrupt arrest. The pathognomonic finding is the anterior displacement of the cervical spinal cord with the detachment of the posterior dura. Systematic clinical evaluation and appropriate diagnostic studies are crucial to rule out a variety of compressive, immune-mediated, and genetic disorders. We present a patient with Hirayama disease whose hand function was improved dramatically by a tendon transfer after nearly 3 years without a definitive diagnosis and call attention to the hand surgeon's role in identifying this rare disease to enable timely functional restoration.

Comparison of cold snare and hot snare polypectomy for the resection of sporadic nonampullary duodenal adenomas.

BACKGROUND AND AIMS: Nonampullary duodenal adenomas can undergo malignant transformation, making endoscopic resection, often by hot snare (HSP) or cold snare polypectomy (CSP), necessary. Although CSP has been shown to be safer for removal of colon polyps, data comparing these techniques for the resection of duodenal adenomas are limited. Our aim was to compare the safety and efficacy of CSP and HSP for the removal of nonampullary duodenal adenomas. METHODS: We performed a retrospective cohort study of patients referred to 2 academic medical centers with a histologically confirmed sporadic, nonampullary duodenal adenoma who underwent endoscopic snare polypectomy between January 1, 2007 and March 1, 2021. Patients with underlying polyposis syndromes were excluded. Outcomes included postprocedural adverse events and polyp recurrence. RESULTS: Of 110 total patients, 69 underwent HSP and 41 underwent CSP. Intraprocedural bleeding was similar between both groups, but 7 patients in the HSP group experienced delayed adverse events versus none in the CSP group (P = .04). Fifty-four patients had complete polyp resection and subsequent surveillance endoscopies. Multivariate analysis showed polyp size to be associated with recurrence (per mm; odds ratio, 1.11; 95% confidence interval, 1.04-1.20; P < .01). Endoscopic resection technique (HSP vs CSP) was not a predictor of recurrence (P = .18). CONCLUSIONS: HSP led to more delayed adverse events compared with CSP, whereas no significant differences on outcomes were noted, suggesting that CSP is equally effective and potentially safer for the removal of duodenal adenomas.

Diagnostic ultrasound of tendon injuries in the setting of distal radius fractures.

OBJECTIVE: Describe tendon injuries and their structural causes seen on ultrasound in wrists with distal radius fractures and estimate the accuracy of ultrasound and its impact on clinical management. MATERIALS AND METHODS: Ultrasounds of 226 wrists (221 patients) with distal radius fractures were retrospectively reviewed. Ultrasound findings of tendon injuries and their structural causes were correlated with surgery and clinical outcome. Accuracy and inter- and intra-observer reproducibilities were calculated. RESULTS: Twenty-five wrists were treated non-operatively while 201 underwent surgery. Ultrasound demonstrated hardware contact with flexor pollicis longus (FPL) in 76 wrists, extensor pollicis longus (EPL) in 21, and other tendons in 94. Ultrasound identified tendon ruptures in 23 wrists (13 EPL/8 FPL/2 extensor indicis proprius (EIP)), most of which were surgically confirmed. Among 12 wrists with confirmed EPL ruptures, distal radius fracture had been treated with volar plating in 6 and non-operatively in 6, and ultrasound showed osseous irregularity at the rupture site in 8. All FPL ruptures occurred in wrists with volar plating. Ultrasound findings were concordant with subsequent clinical management in most. In 2, ultrasound findings led to the decision to remove hardware despite lack of symptoms. Ultrasound had sensitivity/specificity/accuracy of 88/99/98% for identifying a specific tendon as ruptured and 88/87/88% for tendon abnormalities in general. Inter- and intra-observer reproducibilities were excellent (kappa = 0.85 ~ 1.0). CONCLUSION: Certain wrist tendons, particularly EPL and FPL, are vulnerable after distal radius fractures. Ultrasound is accurate and useful for detecting tendon injury and sources of tendon irritation and can guide clinical management.

Traumatic Nondissociative Carpal Instability: A Case Series.

PURPOSE: We report 8 cases of acute or subacute unilateral nondissociative carpal instability (CIND) in the context of nondisplaced scaphoid fractures. METHODS: Eight patients from 3 centers developed abnormal volar intercalated segment instability (VISI) or dorsal intercalated segment instability (DISI) following the diagnosis of a nondisplaced scaphoid fracture. An operative inspection in each patient confirmed intact scapholunate and lunotriquetral interosseous ligaments. We outline the demographic characteristics of our patient cohort, radiologic and operative findings of CIND-DISI and CIND-VISI, and the outcomes of acute and delayed treatment. RESULTS: Two patients were diagnosed with CIND-DISI and 6 with CIND-VISI associated with ipsilateral nondisplaced scaphoid fractures. The average time from injury to diagnosis of CIND was 11 weeks, and the mean clinical and radiographic follow-up was 18 months. Rapid healing of the scaphoid fractures was achieved in all patients (4 open reduction internal fixation, 4 cast). All patients underwent surgery to improve proximal carpal row alignment: in 3 of the 4 patients who were diagnosed and treated surgically within 12 weeks of injury, the radiolunate angle (RLA) was successfully restored. A contracture release and ligament repair or reconstruction with tendon graft 12 or more weeks following injury was unsuccessful in restoring proximal row alignment in all 4 patients. Two patients in the delayed treatment group required secondary surgery for partial fusion. CONCLUSIONS: Based on the arthroscopic, imaging, and operative findings, we propose that the ligamentous restraints to CIND-VISI are dorsal at the radiocarpal joint and volar at the midcarpal joint. Conversely, the ligamentous restraints to CIND-DISI are dorsal at the midcarpal joint and volar at both the radiocarpal and midcarpal joints. In our series, a delayed diagnosis and late reconstructive surgery were associated with no improvement in RLA. We recommend early recognition of traumatic CIND and prompt treatment of injured ligaments prior to the development of a fixed deformity. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

The Dorsal Ligament Complex: A Cadaveric, Histology, and Imaging Study.

PURPOSE: The distinction between the dorsal intercarpal (DIC) and dorsal scaphotriquetral (DST) ligaments is imprecise and unclear in the literature. The purpose of our cadaveric study was to define the origins, insertions, and anatomic relationships of the dorsal wrist ligaments and relate these anatomic findings to magnetic resonance imaging (MRI) scans and histology. METHODS: The study included 17 unmatched fresh-frozen cadaveric specimens (7 male and 10 female), with a mean age of 67.1 years (range, 48-86 years). Wrists with arthritis or carpal malalignment were excluded. Ligaments were dissected and insertion sites were recorded in the radioulnar (width) and proximodistal (length) dimensions, centered at the midpoints of the insertion. Three cadaveric specimens underwent a histologic analysis to demonstrate ligament composition and insertion sites. Three additional cadavers underwent MRI, from which 3-dimensional models were built to model ligament topography. RESULTS: The conjoined triquetral insertion of the DIC, DST, and dorsal radiocarpal (DRC) measured 88.5 ± 6.4 mm2. In each specimen, there were 2 distinct deep and superficial components of intercarpal fibers. The deep component inserted on the lunate with an area of 59.0 ± 5.0 mm2. The deep and superficial components diverged as they coursed radially. The superficial component proceeded to the scaphoid ridge, trapezium, and trapezoid, whereas the deep component inserted on the proximal row. The deep fibers blended distally from their lunate insertion with the DST, forming a robust, 2.9 ± 0.8-mm wide extension over the dorsal capitate. The DRC inserted on the lunate, proximal to the DIC and DST insertions, with an area of 23.9 ± 5.4 mm2. CONCLUSIONS: The dorsal ligament complex forms a firm link across the proximal carpal row and the DST provides extension of the proximal row over the capitate. CLINICAL RELEVANCE: This information can guide surgeons while performing a dorsal approach to the wrist and repairing traumatic ligament disruption.

The Intercalated Segment: Does the Triquetrum Move in Synchrony With the Lunate?

PURPOSE: To quantify the relative motion between the lunate and triquetrum during functional wrist movements and to examine the impact of wrist laxity on triquetral motion. METHODS: A digital database of wrist bone anatomy and carpal kinematics for 10 healthy volunteers in 10 different positions was used to study triquetral kinematics. The orientation of radiotriquetral (RT) and radiolunate rotation axes was compared during a variety of functional wrist movements, including radioulnar deviation (RUD) and flexion-extension (FE), and during a hammering task. The motion of the triquetrum relative to the radius during wrist RUD was compared with passive FE range of motion measurements (used as a surrogate measure for wrist laxity). RESULTS: The difference in the orientation of the radiolunate and RT rotation axes was less than 20° during most of the motions studied, except for radial deviation and for the first stage of the hammering task. During wrist RUD, the orientation of the RT rotation axis varied as a function of passive FE wrist range of motion. CONCLUSIONS: The suggestion that the lunate and triquetrum move together as an intercalated segment may be an oversimplification. We observed synchronous movement during some motions, but as the wrist entered RUD, the lunate and triquetrum no longer moved synchronously. These findings challenge the assumptions behind models describing the mechanical function of the carpals. CLINICAL RELEVANCE: Individual-specific differences in the amount of relative motion between the triquetrum and lunate may contribute to the variability in outcomes following lunotriquetral arthrodesis. Variation in triquetral motion patterns may also have an impact on the ability of the triquetrum to extend the lunate, affecting the development of carpal instability.

Analgesic duration of interscalene block after outpatient arthroscopic shoulder surgery with intravenous dexamethasone, intravenous dexmedetomidine, or their combination: a randomized-controlled trial.

PURPOSE: Both intravenous dexamethasone and dexmedetomidine prolong the analgesic duration of interscalene blocks (ISB) after arthroscopic shoulder surgery. This study compared their relative effectiveness and the benefit of their use in combination. METHODS: This single-centre, double-blinded, parallel three-group superiority trial randomized 198 adult patients undergoing ambulatory arthroscopic shoulder surgery. Patients received preoperative ISB with 30 mL 0.5% bupivacaine and 50 µg dexmedetomidine or 4 mg dexamethasone or both of these agents as intravenous adjuncts. The primary outcome was analgesic block duration. Secondary outcomes included the quality of recovery 15 score (range: 0-150) on day 1 and postoperative neurologic symptoms in the surgical arm. RESULTS: Block durations (n = 195) with dexamethasone (median [range], 24.5 [2.0-339.5] hr) and both adjuncts (24.0 [1.5-157.0] hr) were prolonged compared with dexmedetomidine (16.0 [1.5-154.0] hr). When analyzed by linear regression after an unplanned log transformation because of right-skewed data, the corresponding prolongations of block duration were 59% (95% confidence interval [CI], 28 to 97) and 46% (95% CI, 18 to 80), respectively (both P < 0.001). The combined adjuncts were not superior to dexamethasone alone (-8%; 95% CI, -26 to 14; P = 0.42). Median [IQR] quality of recovery 15 scores (n = 197) were significantly different only between dexamethasone (126 [79-149]) and dexmedetomidine (118.5 [41-150], P = 0.004), but by an amount less than the 8-point minimum clinically important difference. CONCLUSION: Dexamethasone is superior to dexmedetomidine as an intravenous adjunct for prolongation of bupivacaine-based ISB analgesic duration. There was no additional benefit to using both adjuncts in combination. TRIAL REGISTRATION: www.clinicaltrials.gov (NCT03270033); registered 1 September 2017.

RéSUMé: OBJECTIF: La dexaméthasone et la dexmédétomidine intraveineuses prolongent toutes deux la durée analgésique des blocs interscaléniques (BIS) après une chirurgie arthroscopique de l'épaule. Cette étude a comparé leur efficacité relative et les avantages d'une utilisation des deux agents en combinaison. MéTHODE: Cette étude de supériorité monocentrique en trois groupes parallèles à double insu a randomisé 198 patients adultes subissant une chirurgie arthroscopique de l'épaule en ambulatoire. Les patients ont reçu un BIS préopératoire composé de 30 mL de bupivacaïne 0,5 % avec 50 µg de dexmédétomidine, 4 mg de dexaméthasone, ou la combinaison de ces deux agents comme adjuvants intraveineux. Le critère d'évaluation principal était la durée analgésique du bloc. Les critères d'évaluation secondaires comprenaient le score de qualité de récupération (QoR) 15 (plage : 0-150) au jour 1 et les symptômes neurologiques postopératoires dans le bras opéré. RéSULTATS: Les durées des blocs (n = 195) avec la dexaméthasone (médiane [plage], 24,5 [2,0-339,5] heures) et la combinaison des deux adjuvants (24,0 [1,5-157,0] heures) ont été prolongées par rapport à la dexmédétomidine (16,0 [1,5-154,0] heures). Lorsqu'elles ont été analysées par régression linéaire après une transformation logarithmique non planifiée en raison de données biaisées vers la droite, les prolongations correspondantes de la durée du bloc étaient de 59 % (intervalle de confiance [IC] 95 %, 28 à 97) et de 46 % (IC 95 %, 18 à 80), respectivement (les deux P < 0,001). La combinaison des adjuvants n'était pas supérieure à la dexaméthasone seule (-8 %; IC 95 %, -26 à 14; P = 0,42). Les scores médians [ÉIQ] de qualité de récupération 15 (n = 197) n'étaient significativement différents qu'entre la dexaméthasone (126 [79-149]) et la dexmédétomidine (118,5 [41-150], P = 0,004), mais la différence observée était inférieure à la différence minimale de 8 points nécessaire pour être considérée cliniquement importante. CONCLUSION: La dexaméthasone est supérieure à la dexmédétomidine en tant qu'adjuvant intraveineux pour prolonger la durée analgésique d'un BIS à base de bupivacaïne. Aucun avantage supplémentaire n'a été observé lors de l'utilisation combinée des deux adjuvants. ENREGISTREMENT DE L'éTUDE: www.clinicaltrials.gov (NCT03270033); enregistrée le 1er septembre 2017.

Comparative Analysis of 3 Techniques of Scapholunate Reconstruction for Dorsal Intercalated Segment Instability.

PURPOSE: The combination of scaphoid rotatory subluxation, dorsal intercalated segment instability, and dorsal scaphoid translation (DST) constitutes stage 5 scapholunate dissociation in the modified classification system of Garcia-Elias. The purpose of this study was to compare the static radiographic outcomes of reduction and association of the scaphoid and lunate (RASL), three-ligament tenodesis (TLT), and anatomic front and back (ANAFAB) reconstructions for stage 5 scaphoid and lunate malrotation and translation. METHODS: Stage 5 scapholunate dissociation was created in 15 fresh-frozen specimens by cutting the scapholunate interosseous ligament, long radiolunate ligament, dorsal intercarpal ligament, and scaphotrapeziotrapezoid ligament complex. Specimens were randomized to receive 1 of the 3 reconstructive techniques. Radiolunate angle (RLA), scapholunate angle, scapholunate gap, and DST were measured in static fluoroscopic posteroanterior and lateral views in 3 conditions: baseline, injured, and reconstructed. RESULTS: Reduction and association of the scaphoid and lunate showed an improved correction of scapholunate gap compared with TLT and ANAFAB. Anatomic front and back demonstrated an improved correction in RLA and scapholunate angle compared with RASL but not TLT. When the reconstruction was compared with baseline, there was a persistent lunate extension for TLT (RLA and scapholunate angle) and RASL (RLA); however, no significant difference in any parameter was found with ANAFAB. Anatomic front and back significantly improved DST, whereas TLT and RASL did not. CONCLUSIONS: In this cadaveric model of scapholunate dissociation with dorsal intercalated segment instability and DST, each of the 3 repairs had different effects on carpal posture and alignment. While only RASL statistically improved scapholunate gap, only ANAFAB significantly improved DST. Both TLT and RASL improved radiographic parameters; however, each had a persistent increase in the lunate extension following reconstruction. CLINICAL RELEVANCE: It may be prudent to consider different reconstructive techniques for different stages of scapholunate instability. Anatomic front and back, a repair that addresses both dorsal and volar ligament stabilizers, provides improved reduction of dorsal intercalated segment instability and DST in stage 5 scapholunate dissociation.

Is the Dorsal Fiber-Splitting Approach to the Wrist Safe? A Kinematic Analysis and Introduction of the "Window" Approach.

PURPOSE: To compare the kinematic effects of the dorsal fiber-splitting approach for scapholunate ligament repair to a dorsal "window" approach that spares all ligaments. METHODS: We randomized 24 fresh-frozen paired cadaveric forearms to either the dorsal fiber-splitting capsulotomy approach (FSC) or the dorsal window approach (window) following scapholunate interosseous ligament (SLIL) division. Loaded fluoroscopic radiographs were obtained after each of the 4 testing conditions following cyclic loading (200 cycles; 71 N): (1) intact SLIL, (2) SLIL-division, (3) surgical approach, and (4) closure. FSC specimens were randomly allocated to 2 subgroups for closure with either a suture anchor (n = 6) or a simple running suture closure (n = 6). Radiographic parameter measurements included the scapholunate gap, radiolunate angle, scapholunate angle, and dorsal scaphoid translation. RESULTS: Following the FSC, there were significant alterations in all radiographic parameters when compared with the intact and SLIL-division conditions. The window approach did not result in significant changes in any radiographic parameter. When compared to the window approach, all radiographic parameters of the FSC approach were significantly altered. Following closure with suture anchors in the FSC group, radiographic parameters improved, whereas with standard closure they failed to do so. Despite anchor closure, dorsal scaphoid translation, radiolunate angle, and scapholunate angle all remained elevated compared with scapholunate-divided wrists. CONCLUSIONS: The FSC produced significant changes in carpal posture under load, including scapholunate diastasis, dorsal intercalated segment instability, and dorsal scaphoid translation in SLIL-deficient wrists. The window approach preserved the critical dorsal ligament stabilizers and did not produce changes in carpal posture. CLINICAL RELEVANCE: The FSC may create iatrogenic changes in carpal posture that cannot be fully corrected with standard or anchor closure. The window approach does not alter carpal posture and should be considered when performing surgical procedures on the scaphoid or lunate.

A Cadaveric Study on the Utility of the Levator Scapulae Motor Nerve as a Donor for Brachial Plexus Reconstruction.

PURPOSE: The purpose of the study was to evaluate the utility of the levator scapulae motor nerve (LSN) as a donor nerve for brachial plexus nerve transfer. We hypothesized that the LSN could be transferred to the suprascapular nerve (SSN) or long thoracic nerve (LTN) with a reliable tension-free coaptation and appropriate donor-to-recipient axon count ratio. METHODS: Twelve brachial plexus dissections were performed on 6 adult cadavers, bilaterally. We identified the LSN, spinal accessory nerve (SAN), SSN, and LTN. Each nerve was prepared for transfer and nerve redundancies were calculated. Cross-sections of each nerve were examined histologically, and axons counted. We transferred the LSN to target first the SSN and then the LTN, in a tension-free coaptation. For reference, we transferred the distal SAN to target the SSN and LTN and compared transfer parameters. RESULTS: Three cadavers demonstrated 2 LSN branches supplying the levator scapulae. The axon count ratio of donor-to-recipient nerve was 1:4.0 (LSN:SSN) and 1:2.1 (LSN:LTN) for a single LSN branch and 1:3.0 (LSN:SSN) and 1:1.6 (LSN:LTN) when 2 LSN branches were available. Comparatively, the axon count ratio of donor-to-recipient nerve was 1:2.5 and 1:1.3 for the SAN to the SSN and the LTN, respectively. The mean redundancy from the LSN to the SSN and the LTN was 1.7 cm (SD, 3.1 cm) and 2.9 cm (SD, 2.8 cm), and the redundancy from the SAN to the SSN and the LTN was 4.5 (SD, 0.7 cm) and 0.75 cm (SD, 1.0 cm). CONCLUSIONS: These data support the use of the LSN as a potential donor for direct nerve transfer to the SSN and LTN, given its adequate redundancy and size match. CLINICAL RELEVANCE: The LSN should be considered as an alternative nerve donor source for brachial plexus reconstruction, especially in 5-level injuries with scarce donor nerves. If used in lieu of the SAN during primary nerve reconstruction, trapezius tendon transfer for improved external rotation would be enabled.

Surgical Treatment of Iatrogenic Nerve Injury Following Arthroscopic Capsulolabral Repair.

PURPOSE: Case reports of nerve injuries following arthroscopic capsulolabral repair emphasize the proximity of major nerves to the glenoid. This study describes preoperative localization using nerve-sensitive magnetic resonance imaging in a small cohort of patients with iatrogenic nerve injuries following arthroscopic capsulolabral repair and the outcomes of nerve repair in these patients. METHODS: Cases of iatrogenic nerve injury following arthroscopic capsulolabral repair referred to 2 surgeons from January 2017 to December 2019 were identified. Clinical charts, electrodiagnostic testing, magnetic resonance imaging studies, and operative reports were reviewed. RESULTS: Four cases of iatrogenic nerve injury were identified. The time to presentation to our institution ranged from 2 weeks to 8 years. The axillary nerves in 3 cases were tethered by a suture at the inferior glenoid, whereas 1 case had a suture tied around the radial and median nerves inferior to the glenohumeral joint capsule. One case underwent excision and nerve transfer, 1 underwent excision and nerve repair, and 2 underwent suture removal and neurolysis. Open and arthroscopic approaches, including a recently described approach to the axillary nerve in the "blind zone," were used. Three cases demonstrated good recovery of all affected motor and sensory functions after surgery. At the 10-month follow-up, 1 case had persistent weakness, but there was evidence of axonal regeneration on electrodiagnostic testing. CONCLUSIONS: Arthroscopic capsulolabral repair places regional nerves, particularly the axillary nerve, at risk owing to their proximity to the joint capsule and inferior glenoid. Patients with neuropathic pain in the distribution of affected nerves with corresponding sensorimotor loss following arthroscopic capsulolabral surgery should undergo focused magnetic resonance imaging with nerve-sensitive sequences and electrodiagnostic testing to localize the injury. The use of multiple surgical windows to the axillary nerve in the "blind zone" enables full visualization for neurolysis, suture removal, and nerve repair or transfer. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Outcomes of Microneurolysis of Hourglass Constrictions in Chronic Neuralgic Amyotrophy.

PURPOSE: Wide variability in the recovery of patients affected by neuralgic amyotrophy (NA) is recognized, with up to 30% experiencing residual motor deficits. Using magnetic resonance imaging and ultrasound (US), we identified hourglass constrictions (HGCs) in all affected nerves of patients with chronic motor paralysis from NA. We hypothesized that chronic NA patients undergoing microsurgical epineurolysis and perineurolysis of constrictions would experience greater recovery compared with patients managed nonsurgically. METHODS: We treated 24 patients with chronic motor palsy from NA and HGCs identified on magnetic resonance imaging and US either with microsurgical epineurolysis and perineurolysis of HGCs (11 of 24) or nonsurgically (13 of 24). Muscle strength (both groups) and electrodiagnostic testing (EDX) (operative group) was performed before and after surgery. Preoperative EDX confirmed muscle denervation in the distribution of affected nerve(s). All patients met criteria for microneurolysis: 12 months without improvement since onset or failure of clinical and EDX improvement after 6 months documented by 3 successive examinations, each at least 6 weeks apart. RESULTS: Mean time from onset to surgery was 12.5 ± 4.0 months. Average time to most recent post-onset follow-up occurred at 27.3 months (range, 18-42 months; 15 nerves). Average time to latest follow-up among nonsurgical patients was 33.6 months (range, 18-108 months; 16 nerves). Constrictions involved individual fascicular groups (FCs) of the median nerve and the suprascapular, axillary and radial nerves proper (HGCs). Nine of 11 operative patients experienced clinical recovery compared with 3 of 13 nonsurgical patients. EMG revealed significant motor unit recovery from axonal regeneration in the operative group. CONCLUSIONS: Microsurgical epineurolysis and perineurolysis of FCs and HGCs was associated with significantly improved clinical and nerve regeneration at an average follow-up of 14.8 months compared with nonsurgical management. We recommend microneurolysis of HGCs and FCs as a treatment option for patients with chronic NA who have failed to improve with nonsurgical treatment. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Fascicular constrictions above elbow typify anterior interosseous nerve syndrome.

INTRODUCTION: In this study we tested the hypothesis that fascicular constrictions (FCs) of the median nerve proximal to the elbow joint characterize anterior interosseous nerve syndrome (AINS). METHODS: Magnetic resonance neurography (MRN) and ultrasound (US) examinations were evaluated in 45 patients with clinically suspected AINS. All 22 patients at site 1 underwent MRN and 8 underwent US; all 23 patients at site 2 underwent US. RESULTS: Median nerve FCs were identified in all MRN cases; FCs and/or fascicular enlargements were identified in 88% of US cases. Most FCs were in the mediannerve posterior/posteromedial region and were proximal to the elbow joint line (mean distance: MRN, 5.4 cm; US, 7.5 cm), with the exception of a single FC (located 1 cm distal). No extrinsic compression of median or anterior interosseous nerves was identified in the arm or forearm. DISCUSSION: AINS is a noncompressive neuropathy characterized by median nerve FCs in the arm.

Interstitial granulomatous dermatitis and granulomatous arteritis in the setting of PD-1 inhibitor therapy for metastatic melanoma.

Checkpoint inhibition has become an important target in the management of malignant melanoma. As anti-CTLA4 inhibitors and anti-PD1 antibodies are increasingly utilized, reports of immune-related adverse events (IRAEs) are becoming more frequent. Common noted cutaneous IRAEs are morbilliform, lichenoid, bullous, granulomatous, psoriasiform, and eczematous eruptions. We report a case of interstitial granulomatous dermatitis and granulomatous arteritis in the setting of nivolumab (anti-PD1) monotherapy for metastatic melanoma. There are many different causes for granulomatous vasculitis, such as herpes virus infection, lymphoproliferative disorders, systemic vasculitis, and inflammatory bowel disease. This report adds to the growing literature on granulomatous IRAEs due to checkpoint inhibition.

Reevaluation of the Scaphoid Fracture: What Is the Current Best Evidence?

Scaphoid fractures are common and notorious for their troublesome healing. The aim of this review is to reevaluate the current best evidence for the diagnosis, classification, and treatment of scaphoid fractures and nonunions. MRI and CT are used to establish a "definitive diagnosis" with comparable diagnostic accuracy although neither is 100% specific. Current classifications cannot reliably predict union or outcomes; hence, a descriptive analysis of fracture location, type, and extent of displacement remains most useful. Treatment of a nondisplaced scaphoid waist fracture remains an individualized decision based on shared decision-making. Open reduction and internal fixation may be preferred when fracture displacement exceeds 1 mm, and the fracture is irreducible by closed or percutaneous means. For unstable nonunions with carpal instability, either non-vascularized cancellous graft with stable internal fixation or corticocancellous wedge grafts will provide a high rate of union and restoration of carpal alignment. For nonunions characterized with osteonecrosis of the proximal pole, vascularized bone grafting can achieve a higher rate of union.