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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Overcoming the Axillary Nerve Blind Spot Through the Deltopectoral and Axillary Approaches: A Cadaveric Study.

PURPOSE: The aim of this study was to evaluate the feasibility of exploring the axillary nerve (AN) at the 6 o'clock position (blind spot) using the deltopectoral approach, with the interval lateral to the conjoint tendon (CJT) or combined with the axillary approach. METHODS: Four ANs were dissected combining the deltopectoral approach-medial to the CJ (A), the deltopectoral approach-lateral to the CJT (B) and the axillary approach (C) in 3 sequences: A-B-C, B-A-C, and C-B-A. After the first approach was completed, the proximal and distal margins were marked. Additional exposure with the second and third approaches and the 6 o'clock position were also marked. Then, the AN was excised and the amount of exposed nerve with the 3 approaches was measured. RESULTS: The deltopectoral approach-medial to the conjoint tendon did not allow exposure of the AN at the 6 o'clock position. Six o'clock position exposure was accomplished using the lateral interval of the deltopectoral and the axillary approaches. A deltopectoral approach lateral to the CJT allowed exploration of the AN at the blind spot, but not the terminal branches. The axillary approach was able to expose the AN at the 6 o'clock position, the terminal branches, but not the nerve-muscle junction. Combining the 3 approaches exposed 81% to 94% of the total length of the AN. CONCLUSIONS: The deltopectoral approach allowed visualization of the AN at the 6 o'clock position when explored lateral to the CJT. The axillary approach allowed visualization of the terminal branches of the AN and the 6 o'clock position of the glenoid. CLINICAL RELEVANCE: The deltopectoral approach lateral to the conjoint tendon allows the surgeon to assess continuity of the AN at the 6-o'clock position and to perform a neurolysis. If nerve repair, nerve grafting, or nerve transfer is attempted, a combination of the 3 approaches could be used.

Cadaveric Evaluation of Myelinated Nerve Fiber Count in the Nerve to the Gracilis Muscle in Relation to Use as a Free Functional Muscle Transfer for Elbow Flexion.

BACKGROUND: Optimizing axon count is essential for successful nerve transfer surgery, and a donor-to-recipient axon count ratio greater than 0.7:1 has been associated with improved outcomes. A gracilis free functioning muscle transfer (FFMT) is an option to restore elbow flexion, but its axon count has not been evaluated. Our aim was to quantify the axon count of the nerve to the gracilis muscle. METHODS: The nerve to the gracilis was dissected in 10 fresh frozen adult cadaveric hindquarter specimens (four females and six males). The length of the nerve to the gracilis was measured and a biopsy taken. A validated histologic preparation technique was utilized, and axons were counted. The mean length and axon counts were calculated. RESULTS: The average axon count in the nerve to the gracilis was 818 (range = 684-1,000, standard deviation [SD] = 116). The average length was 98 mm (range = 81-115 mm, SD = 13 mm). CONCLUSION: Our study found the average axon count in the nerve to the gracilis was 818. Prior literature suggests axon count ratio greater than 0.7:1 is associated with better clinical outcomes. Using data from prior studies, the spinal accessory, three intercostal, and two intercostal nerves are all sufficient for the transfer to the nerve to the gracilis with donor to recipient ratios of 1.7:1, 1.3:1, and 0.9:1, respectively.

Self-identified functional limitations improve in patients with degenerative wrist arthritis after surgery.

STUDY DESIGN: This is a prospective cohort pilot study. BACKGROUND: Degenerative wrist arthritis leads to pain, loss of strength, mobility, function, and impairments in psychological well-being. Accurate assessment of functional limitations that are unique to the individual is essential for successful treatment that best meets those specific needs. PURPOSE OF THE STUDY: To identify and determine if self-identified functional limitations improve in patients who underwent surgery for degenerative wrist arthritis. METHODS: Patients with degenerative wrist arthritis who were scheduled for surgery were prospectively recruited (n = 14, mean age + SD = 42 + 16, 10 males, 4 females) into a pilot study that measured self-identified functional limitations and outcomes. Inclusion criteria included a diagnosis of scapholunate advanced collapse, scaphoid nonunion advanced collapse, scapholunate interosseous ligament tear, or Kienböck disease. Exclusion criteria included a history of neuromuscular disease or concomitant ipsilateral musculoskeletal injury. Data were collected during two 20-minute sessions, preoperatively and one year postoperatively, utilizing the Patient-Rated Wrist Evaluation and the Canadian Occupational Performance Measure. RESULTS: All patients reported significant decreases (P < .001) in total pain (mean change = 17.6, SD = 8.5) and total disability (mean = 17.8, SD = 9.1) on the Patient-Rated Wrist Evaluation from presurgery to postsurgery, with a large effect size of d > 0.8. Patients also reported significant improvements (P < .001) in mean performance (mean = 3.5, SD = 1.5) and mean satisfaction (mean = 4.0, SD = 2.1) with self-identified activities on the Canadian Occupational Performance Measure, with an effect size of d > 0.8. CONCLUSION: Patients with degenerative wrist arthritis reported significant postoperative improvement in both performance and satisfaction in self-identified activities. Consideration of patient-specified goals can inform both patients and clinicians during the surgical decision-making process and allow for more individualized care.

Ultrasound imaging of brachial plexus trauma in gunshot injury.

INTRODUCTION: Brachial plexus trauma related to gunshot (GS) injury requires early examination and characterization to ensure appropriate treatment. Magnetic resonance imaging (MRI) may be contraindicated when there are metal fragments in a patient's body. Ultrasound (US) may present an alternative to imaging GS-related brachial plexus injury. METHODS: Three patients with GS-related brachial plexus injury who underwent US imaging evaluation at our institution were identified. A retrospective review of the patients' medical records was performed. RESULTS: US characterization of nerve abnormalities after GS injury to the brachial plexus was in agreement with electrodiagnostic and intraoperative findings. DISCUSSION: Information from the US reports was useful in preparation for brachial plexus reconstruction surgery. As such, US has unique utility when MRI cannot be performed. US imaging can provide useful characterization of the brachial plexus after GS injury when performed by an experienced operator. Muscle Nerve 59:707-711, 2019.

Electrodiagnostic evidence of suprascapular nerve recovery after decompression.

INTRODUCTION: The purpose of this study was to determine whether surgical arthroscopic decompression or ultrasound-guided aspiration of a paralabral cyst would result in suprascapular nerve recovery from axonal regeneration based on electrodiagnostic testing. METHODS: Nine patients with preoperative electromyography (EMG) evidence of suprascapular neuropathy due to paralabral cysts at the suprascapular or spinoglenoid notch were prospectively studied. Eight patients underwent arthroscopic surgical decompression, and 1 patient underwent ultrasound-guided aspiration. Postoperative EMG was performed in all patients to evaluate nerve regeneration. RESULTS: Three (33%) patients had cysts at the suprascapular notch, whereas 6 (67%) patients had cysts at the spinoglenoid notch. All patients showed complete electrophysiological recovery after decompression. DISCUSSION: Decompression of paralabral cysts at the suprascapular or spinoglenoid notch resulted in postoperative EMG evidence of nerve recovery. Long-term studies with a greater number of patients are required to elucidate time to recovery. Muscle Nerve 59:247-249, 2019.

Kinematic Accuracy in Tracking Total Wrist Arthroplasty With Biplane Videoradiography Using a Computed Tomography-Generated Model.

Total wrist arthroplasty (TWA) for improving the functionality of severe wrist joint pathology has not had the same success, in parameters such as motion restoration and implant survival, as hip, knee, and shoulder arthroplasty. These other arthroplasties have been studied extensively, including the use of biplane videoradiography (BVR) that has allowed investigators to study the in vivo motion of the total joint replacement during dynamic activities. The wrist has not been a previous focus, and utilization of BVR for wrist arthroplasty presents unique challenges due to the design characteristics of TWAs. Accordingly, the aims of this study were (1) to develop a methodology for generating TWA component models for use in BVR and (2) to evaluate the accuracy of model-image registration in a single cadaveric model. A model of the carpal component was constructed from a computed tomography (CT) scan, and a model of the radial component was generated from a surface scanner. BVR was acquired for three anatomical tasks from a cadaver specimen. Optical motion capture (OMC) was used as the gold standard. BVR's bias in flexion/extension, radial/ulnar deviation, and pronosupination was less than 0.3 deg, 0.5 deg, and 0.6 deg. Translation bias was less than 0.2 mm with a standard deviation of less than 0.4 mm. This BVR technique achieved a kinematic accuracy comparable to the previous studies on other total joint replacements. BVR's application to the study of TWA function in patients could advance the understanding of TWA, and thus, the implant's success.