Assisting in Microsurgery: Operative and Technical Considerations.

Microsurgery is technically challenging, typically requiring a primary surgeon and an assistant to complete several key operative steps. These may include manipulation of fine structures, such as nerves or vessels in preparation for anastomosis; stabilization of the structures; and needle driving. Even seemingly mundane tasks of suture cutting and knot tying require fine coordination between the primary surgeon and assistant in the microsurgical environment. Although prior literature discusses the implementation of microsurgical training centers at academic institutions and residency programs, there is a paucity of work describing the role of the assistant surgeon in a microsurgery operation. In this surgical technique article, the authors discuss the role of the assisting surgeon in microsurgery, with recommendations for trainees and attendings alike.

Predicting early term complications of ORIF distal radius fracture in outpatient settings using NSQIP data.

PURPOSE: There is no consensus on which risk factors are most predictive for complications following open reduction internal fixation of distal radius fractures (ORIF-DRF) in an outpatient setting. This study is a complication risk analysis for ORIF-DRF in outpatient settings based on data obtained from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP). METHODS: A nested, case-control study, was conducted in ORIF-DRF cases performed in outpatient settings from 2013 to 2019 obtained from the ACS-NSQIP database. Cases with documented local or systemic complications were age and gender-matched in a 1:3 ratio. The association between patient and procedure-dependent risk factors for systemic and local complications in general and for different subpopulations was examined. Bivariate and multivariable analyses were performed to evaluate the association between risk factors and complications. RESULTS: From a total of 18,324 ORIF-DRF, 349 cases with complications were identified and matched to 1047 Controls. Independent patient-related risk factors included a history of smoking, the American Society of Anesthesiologists (ASA) Physical Status Classification 3 and 4, and bleeding disorder. The intra-articular fracture with three or more fragments was found to be an independent risk factor of all procedure-related risk factors. History of smoking was found to be an independent risk factor for all gender populations, as well as for patients younger the 65 years old. For older patients (age ≥65) bleeding disorder was found to be an independent risk factor. CONCLUSION: Complications of ORIF-DRF in outpatient settings have many risk factors. This study provides surgeons with specific risk factors for possible complications following ORIF-DRF.

Neuroma-in-continuity: a review of pathophysiology and approach to the affected patient.

A neuroma-in-continuity is a neuroma resulting from a nerve injury in which internal neuronal elements are partially disrupted (with a variable degree of disruption to the endoneurium and perineurium) while the epineurium typically remains intact. The portion of injured axons are misdirected and embedded in connective tissue, which may give rise to local neuroma pain and a distal nerve deficit. The lesion may result from a multitude of injury mechanisms, and clinical presentation is often variable depending on the nerve affected. Clinical, electrodiagnostic, and imaging examinations are helpful in assessing the extent and degree of the lesion. If no clear evidence of recovery is identified within 3-4 months post-injury, the patient may benefit from operative exploration. Surgical management options include neurolysis, neuroma resection, nerve grafting, and nerve transfer, or a combination of modalities. A primary consideration of surgery is the possibility of further downgrading nerve function in the pursuit of more, thereby highlighting the need to carefully weigh the advantages and disadvantages prior to surgical intervention. The objective of this review article is to describe the current understanding of the pathophysiology of neuroma-in-continuity lesions, and to review the approach to the affected patient including clinical evaluation, ancillary testing, and intraoperative assessment and treatment options.

Targeted Muscle Reinnervation for Treatment of Postresection Interdigital Neuroma: A Cadaveric Feasibility Study.

BACKGROUND: Symptomatic postresection interdigital neuroma is a frustrating problem that causes debilitating foot pain. Implementing the concepts of targeted muscle innervation, this study offers a novel nerve transfer involving the resected third common plantar digital nerve (CPDN) to the motor nerve branch of the third dorsal interosseous muscle (DIMB) to improve postresection pain. METHODS: Ten fresh feet from seven cadaveric donors were used for this study. CPDN and DIMB lengths and diameters were measured, along with nerve overlap after the transfer with ankle in neutral position and in maximal dorsiflexion. Motor entry point to the calcaneal tuberosity and to the fifth metatarsal tuberosity were measured and used to evaluate the ratio relative to foot length. Means, standard deviations, and P values were calculated for each measure and between sexes and feet (right and left). RESULTS: In all specimens, the nerve transfer was technically feasible, without notable size mismatch between the donor and recipient nerves. CPDN, DIMB, and important anatomical reference points were identifiable in all specimens. Average CPDN length was 30.1 ± 8.2 mm. The average DIMB length was 14.4 ± 3.9 mm. The overlap between the donor and recipient in neutral ankle position at the transfer site was 6.4 ± 1.8 mm. CONCLUSIONS: Given their anatomical locations, a nerve transfer between the third CPDN and third DIMB is surgically feasible. This novel technique is a viable option that can be used instead of the conventional technique of muscle implantation or more proximal re-resection for symptomatic postresection interdigital neuroma.

Two Cases of Delayed Flexor Tendon Rupture Decades After Reconstruction.

Two patients are presented with late-term ruptures of their flexor tendon grafts 10 and 40 years, respectively, after reconstruction. Both occurred from low-energy mechanisms. Their ruptures were intratendinous and not at the proximal or distal insertions. Electron microscopy demonstrated degeneration and increased matrix deposition. Immunohistology showed viable tenocytes, but no clear vascular organization to the disrupted grafts. Even after clinically successful flexor tendon autograft, tendons may still be at risk of degeneration and rupture a decade or more after reconstruction.

What a Waste! The Impact of Unused Surgical Supplies in Hand Surgery and How We Can Improve.

BACKGROUND: The US health care system is the second largest contributor of trash. Approximately 20% to 70% of waste is produced by operating rooms, and very few of this waste is recycled. The purpose of this study is to quantify the opened but unused disposable supplies and generate strategies to reduce disposable waste. METHODS: A single-center prospective study to evaluate the cost of opened but unused single-use operating room supplies was completed by counting the number of wasted disposable products at the end of hand surgery cases. We used χ2 test, t test, Wilcoxon rank-sum test, and simple linear regression to assess the associations between patient and case variables and the total cost of wasted items. Environmentally Extended Input Output Life Cycle Assessment methods were used to convert the dollar spent to kilograms of carbon dioxide equivalent (CO2-e), a measure of greenhouse gas emissions. RESULTS: Surgical and dressing items that were disposed of and not used during each case were recorded. We included 85 consecutive cases in the analysis from a single surgeon's practice. Higher cost from wasted items was associated with shorter operative time (P = .010). On average, 11.5 items were wasted per case (SD: 3.6 items), with a total of 981 items wasted over the 85 cases in the study period. Surgical sponges and blades were 2 of the most unused items. Wasted items amounted to a total of $2193.5 and 441 kg of CO2-e during the study period. CONCLUSIONS: This study highlights the excessive waste of unused disposable products during hand surgery cases and identifies ways of improvement.

Feasibility of Nerve Transfer to Palmaris Longus in Forearm-Level TMR: Anatomic Study and Clinical Series.

BACKGROUND: Targeted muscle re-innervation (TMR) is increasingly being used for treatment of postamputation pain and myoelectric prosthesis (MYP) control. Palmaris longus (PL) is a potential target following transradial amputation. The purpose of this study was to determine the branching pattern of the median nerve (MN) as it pertains to the PL motor branch entry point (MEP) and to present clinical results of patients who had PL used as a target. METHODS: Eight cadaveric arms were dissected and branching patterns of the MN were documented. Additionally, we reviewed adult patients from a prospectively collected database who underwent TMR using PL. We recorded patient-reported outcomes and signal strength generated by the PL. RESULTS: The average distance from the medial epicondyle to PL MEP was 53 mm. All palmaris motor branches passed through a chiasm within the flexor digitorum superficialis muscle belly, which was a mean of 18 mm away from the MN proper. Patients with long-term follow-up reported an average Pain visual analog scale of 3.3 and Disabilities of the Arm, Shoulder and Hand of 46.2. All but one patient were using an MYP, and all generated at least 10 mV of signal from the PL, which is ample signal for surface electrode detection and MYP control. There were no postoperative neuromas and only one patient-reported postoperative phantom limb pain. CONCLUSIONS: Palmaris longus is a suitable target for TMR. Our objective measurements and anatomic relationships may help surgeons consistently find the PL's motor branch. Our series of patients reveal sufficient signal strength and acceptable clinical outcomes following TMR using the PL.

Central slip and bilateral lateral band laceration with negative Elson's and modified Elson's tests.

Elson's test is the gold standard clinical exam for assessing central slip integrity, but the test and its modifications were historically applied to isolated central slip injuries with intact lateral bands (Elson, 1986; Schreuders et al., 2006). This case report presents an open zone III extensor injury to the right index finger with complete laceration of the central slip and bilateral lateral bands. No prior reports of this injury, specifically one without any associated bony or neurovascular injury, have been explicitly described in the literature. Physical examination in this case demonstrated complete digital extensor lag at the interphalangeal joints, and false negative Elson's and modified Elson's tests. It is important to remain aware that complete laceration of the central slip and bilateral lateral band disruption is a possibility with zone III extensor lacerations. Importantly, Elson's test and its modifications have limited utility for these particular injuries, as the lateral bands cannot transmit extension forces to the terminal tendon.

Dorsal Fixation of Coronal Hamate and Fifth Metacarpal Base Fractures: An Anatomic Evaluation of the Ulnar Nerve.

PURPOSE: Traumatic drill overshoot during dorsal fixation of coronal hamate and fifth metacarpal base fractures risks iatrogenic ulnar nerve injury. This study describes the anatomic relationships between exiting volar drill tips and ulnar nerve branches. METHODS: Dorsal drilling of hamate bones and fifth metacarpal bases was performed on cadavers. Dorsal hamate bodies were subdivided into 4 quadrants: (1) distal-ulnar, (2) distal-radial, (3) proximal-ulnar, and (4) proximal-radial. Screws measuring 5 mm more than the dorsal-to-volar bone depths were placed in each quadrant to represent drill exit trajectories with consistent overshoot. A single screw was similarly placed 5 mm distal to the midline articular surface of the dorsal fifth metacarpal base. Distances between estimated drill tips and ulnar nerve branches were measured. RESULTS: Ten cadaver hands were examined. The fifth metacarpal base screw tips directly abutted the ulnar motor branch in 6 hands, and were within 1 mm in 4 hands (mean, 0.4 ± 0.5 mm). Distances from the tips to the ulnar motor and sensory branches were largest in the distal-radial quadrant (11.8 ± 0.8 mm and 9.2 ± 1.9 mm, respectively) and smallest in the proximal-ulnar quadrant (7.3 ± 1.5 mm and 4.3 ± 1.1 mm, respectively). Distances to the ulnar motor and sensory branches were similar between the proximal-ulnar and distal-ulnar quadrants, and between the proximal-radial and distal-radial quadrants. CONCLUSIONS: Dorsal drilling of coronal hamate fractures appears to be safe, as volar drill tips are well away from ulnar nerve motor and sensory branches. Distances to ulnar nerve branches are largest, and theoretically safest, with dorsal drilling in the distal-radial hamate. Dorsal drilling of fifth metacarpal base fractures appears to carry a high risk for potential ulnar motor nerve injury. CLINICAL RELEVANCE: These findings may help minimize potential risks for iatrogenic ulnar nerve injury with dorsal drilling of hamate and fifth metacarpal base fractures.

Factors Associated with Timing of Syndactyly Release in the United States.

Background: Syndactyly is one of the commonly encountered congenital hand anomalies. However, there are no strict guidelines regarding the timing of surgical release. The aim of this study was to investigate the age and factors associated with syndactyly release in the United States. Methods: A retrospective analysis of the California and Florida State Ambulatory Surgery and Services Databases for patients aged 18 years or younger who underwent syndactyly release surgery between 2005 and 2011 was performed. Demographic data that included the age at release, gender, race and primary payor (insurance) was collected. A sub-analysis was performed to compare the demographic characteristics between those patients undergoing syndactyly release before 5 years of age ('Early Release') and at (of after) 5 years ('Late Release'). Results: A total of 2,280 children (68% male, 43% Caucasian) were identified. The mean age of syndactyly release was 3.6 years, and 72.9% of patients underwent release before the age of 5 years. A significantly larger proportion of females (p = 0.002), and Hispanics and African Americans (p = 0.024), underwent late release compared to early release. Additionally, a significantly higher percentage of patients undergoing late release utilised private insurance (p = 0.005). However, the actual differences in gender, race and primary payor were small. Conclusion: The majority of syndactyly releases were performed before school age, which is the primary goal in the management of syndactyly. While gender and racial disparities in the surgical treatment of syndactyly may exist, the differences in the present study were relatively small. Level of Evidence: Level III (Therapeutic).

Selective transfer of nerve to supinator to restore digital extension in central cord syndrome: An anatomical study and a case report.

BACKGROUND: Nerve transfers are increasingly used to restore upper extremity function in patients with spinal cord injury. However, the role of nerve transfers for central cord syndrome is still being established. The purpose of this study is to report the anatomical feasibility and clinical use of nerve transfer of supinator motor branches (NS) to restore finger extension in a central cord syndrome patient. MATERIALS AND METHODS: The posterior interosseous nerve (PIN), its superficial division, and branches were dissected in 14 fresh cadavers, with a mean age of 65 (58-79). Measurements included number and length of branches of donor and recipient, diameters, regeneration distance from coaptation site to motor entry point and axonal counts. A NS transfer to extensor carpi ulnaris (ECU), extensor digiti quinti (EDQ) and extensor digitorum communis (EDC) was performed in a 28-year-old patient, with central cord syndrome after a motorcycle accident, who did not recover active finger extension at 10 months post injury. RESULTS: The PIN consistently divided into a deep and superficial branch between 1.5 cm proximal to, and 2 cm distal to the distal boundary of the supinator. The superficial branch provided a first common branch to the ECU and EDQ. In 12/14 dissections, the EDC was innervated by a 4 cm long branch that entered the muscle on its radial deep surface. In all cases, the superficial branch of the PIN could be separated in a retrograde fashion from the PIN and coapted with NS. The mean myelinated fiber count in nerve to EDC was 401 ± 190 compared to 398 ± 75 in the NS. At 48 months after surgery, with the wrist at neutral, the patient recovered full metacarpophalangeal extension scoring M4. Supination was preserved with the elbow extended or flexed. CONCLUSIONS: Restoration of finger extension in central cord syndrome is possible with a selective transfer of the NS to EDC, and is anatomically feasible with a short regeneration distance and favorable axonal count ratio.

Hand and Upper Extremity Trauma in the Undocumented Immigrant Population in the United States.

Undocumented immigrants in the United States are at risk for upper extremity trauma due to occupational exposure, and decreased access to healthcare can worsen outcomes. The purpose of this study was to compare documented versus undocumented patients in a large cohort of patients in New York City's most diverse neighborhood in order to characterize upper extremity trauma in this population. METHODS: The Elmhurst Hospital trauma database was examined for patients admitted with upper extremity trauma from April 2016 to December 2019. Charts were examined for demographic information, documentation status, injury mechanism, and outcomes. RESULTS: Of the 1041 patients included, 865 (83.1%) were documented and 176 (16.9%) were undocumented. Undocumented immigrants were younger (40.5 versus 62.4 years, P < 0.0001) and predominantly men (83.5% versus 57.1%, P < 0.0001) with fewer comorbidities (42.6% versus 64.6%, P < 0.0001). Occupational injury was three times as likely in undocumented immigrants (13.6% versus 4.6%, P < 0.0001) and these patients were nearly twice as likely to be harmed from violence (19.9% versus 10.2%, P = 0.0003). Increased rates of injury during bicycle/motorcycle accidents (8.0% versus 3.0%, P = 0.0017) or being struck as a pedestrian (21.6% versus 14.3%, P = 0.0149) were found in the undocumented cohort, with falls (39.8% versus 59.3%, P < 0.0001) or vehicle collisions (0.6% versus 3.5%, P = 0.0402). CONCLUSIONS: Undocumented patients with upper extremity trauma represent a younger/healthier cohort, but are more likely to be injured at work or by violence. Documentation status plays a role in injury characteristics.

Hand Function Following Simulated Fusion of Thumb Metacarpophalangeal and Interphalangeal Joints.

Background: There is poor understanding regarding functional limitation of thumb strength and dexterity following thumb metacarpophalangeal (MCP) and interphalangeal (IP) arthrodesis. The purpose of this investigation was to quantitatively evaluate the functional limitations of MCP and IP joint fusion using an orthosis to simulate fusion. Methods: Thirty-two healthy volunteers underwent simulated MCP and IP thumb arthrodesis using custom-molded orthoses. Each volunteer was independently assessed for hand and thumb function using the Jebsen-Taylor Hand Function test, lateral pinch strength, tip pinch strength, and Grooved Pegboard test. Comparisons between the 3 groups in all functional tests were carried out. Results: The mean lateral pinch strength was significantly greater in the unsplinted group (8.3 kg) compared with the MCP- (6.3 kg) and IP-splinted (5.7 kg) groups. Mean tip pinch strength was also significantly higher in the unsplinted group than in MCP- and IP-splinted thumbs (4.6 kg vs 4.1 and 3.9 kg). There was no difference in the Jebsen-Taylor or Grooved Pegboard test between the 3 groups. Conclusion: Our study suggests that with a fused MCP joint the lateral and tip pinch strength will decrease by 24% and 10%, respectively, compared with a healthy nonsplinted thumb. A fused IP joint will decrease lateral and tip pinch by 31% and 16%, respectively. This information does not take into account an arthritic thumb. We found that the Jebsen-Taylor test and Grooved Pegboard test were not affected by simulated thumb MCP and IP fusion.

The Cutting Edge: Surface Texture Analysis following Resection of Nerve Stumps Using Various Instruments.

BACKGROUND: Preparation of nerve ends is an essential part of nerve repair surgery. Multiple instruments have been described for this purpose; however, no consensus exists regarding which is the least traumatic for tissue handling. We believe that various instruments used for nerve-end excision will lead to different surface roughness. METHODS: Median and ulnar nerves from fresh frozen cadavers were dissected, and 1-2 cm lengths were excised using a No. 11 blade, a razor blade, or a pair of scissors. Using electron microscopy, 3-dimensional surface analysis of roughness (Sa) for each specimen was performed using ZeeScan optical hardware and GetPhase software (PhaseView, Buisson, France). An ANOVA or Kruskal-Wallis test compared roughness measures among cutting techniques. RESULTS: Forty nerves were included. Of these, 13 (32.5%) were cut using scissors, 15 (37.5%) using a razor blade, and 12 (30%) using a No. 11 blade. An ANOVA test showed statistical differences in Sa among the cutting techniques (P = 0.002), with the lowest mean Sa noted in the scissors group (7.2 µM, 95% CI: 5.34-9.06), followed by No. 11 blade (7.29 µM, 95% CI: 5.22-9.35), and razor blade (11.03 µM, 95% CI: 9.43-12.62). Median Ra (surface profile roughness) was 4.58 (IQR: 2.62-5.46). A Kruskal-Wallis test demonstrated statistical difference in Ra among techniques (P = 0.003), with the lowest by No. 11 blade (3 µM, IQR: 1.87-4.38), followed by scissors (3.29 µM, IQR: 1.56-4.96), and razor (5.41 µM, IQR: 4.95-6.21). CONCLUSION: This novel technique of 3-dimensional surface analysis found razor blade use demonstrated poor roughness, whereas a No. 11 blade or nerve-specific scissors led to equivocally smooth nerve ends.

Trends in Peripheral Nerve Epidemiology and Reconstruction: A State Database Study of Direct Repairs, Grafts, and Conduits.

BACKGROUND: Peripheral nerve injuries (PNIs) are most commonly treated with direct nerve repair procedures or nerve autografts. However, recent advancements in synthetic and vein conduits have led to their increased utilization. The present study quantifies the incidence of these procedures over time and geography and identifies differences in complication rates, illustrating the current epidemiologic climate regarding conduit use for PNI repair. METHODS: A query was conducted using the State Ambulatory Surgery and Services Databases data from 2006 to 2011 in both Florida and California for patients undergoing nerve repair, nerve grafting, synthetic conduits, and vein conduits. Patient zip code data were analyzed to determine the geographic distribution of various types of repair. In addition, text-mining algorithms were used to identify trends in PNI-related publications. RESULTS: In the 6-year period investigated, direct nerve repair was the most frequently used procedure for PNIs. However, the utilization of direct repairs declined significantly from 2006 to 2011. Synthetic and vein conduits demonstrated a significant increase over the same period. There were significantly higher rates of complications for autologous grafts (3.3%), vein conduits (3.5%), and synthetic conduits (2.4%), as compared with direct nerve repairs (1.4%). There was a nonsignificant difference in infection rates between these types of nerve repair. CONCLUSIONS: From an epidemiologic perspective, both graft and synthetic conduit-based PNI repairs are increasing in prevalence both in clinical practice and in the academic literature. This will likely continue in the future with the development of advancements in biologic and synthetic nerve conduit PNI repair options.

Narrative Review of Ligamentous Wrist Injuries.

Ligamentous wrist injuries are common occurrences that require complex anatomical mastery and extensive understanding of diagnostic and treatment modalities. The purpose of this educational review article is to delve into the most clinically relevant wrist ligaments in an organized manner to provide the reader with an overview of relevant anatomy, function, clinical examination findings, imaging modalities, and options for management. Emphasis is placed on elucidating reported diagnostic accuracies and treatment outcomes to encourage evidence-based practice.

Musculoskeletal Ultrasonography of the Extremities: Clinical and Ultrasonographic Correlation.

Ultrasonography as a diagnostic and therapeutic tool has become a resource for musculoskeletal injuries. It can be a useful imaging modality for clinical correlation of physical examination findings as well as an aid for image-guided procedures. Understanding the settings in which it is a helpful adjunct will have implications on efficiency and cost utility. The objectives of this chapter are to provide a background of ultrasonography as a musculoskeletal imaging modality, provide clinical correlation for ultrasonographic findings for common upper extremity pathology, review the diagnostic efficacy of ultrasonography for image-guided procedures, and provide insight into the cost utility of ultrasonography guidance for therapeutic injections.

Multistate Comparison of Cost, Trends, and Complications in Open Versus Endoscopic Carpal Tunnel Release.

Background: Surgical carpal tunnel release is performed by either open carpal tunnel release (OCTR) or endoscopic carpal tunnel release (ECTR). The purpose of this study was to assess differences in intraoperative and postoperative complications, trends, and costs between OCTR and ECTR. Methods: State Ambulatory Surgery and Services Databases (SASD) files for California, Florida, and New Jersey were queried for patients who underwent OCTR and ECTR between 2000 and 2014. Patient demographics, comorbidities, intraoperative and postoperative complications, and cost were compared between OCTR and ECTR. The frequency of each procedure was used to formulate trends in OCTR and ECTR. Results: A total of 571 403 patients were included in this study. Sex was significantly different by a small percentage (OCTR = 64.8% female, ECTR = 65.4% female). A higher proportion of Hispanic patients underwent ECTR (P < .001). The patients who underwent OCTR had a greater comorbidity burden in terms of diabetes and rheumatoid arthritis (P < .001). None of the aforementioned complication rates were statistically significant between the 2 procedures. Endoscopic carpal tunnel release was significantly more costly by almost $2000. Open carpal tunnel release has remained stable over the years studied, whereas ECTR increased 3-fold. Conclusions: Our findings demonstrate no significant differences between OCTR and ECTR regarding intraoperative and postoperative complications and patient outcomes. Endoscopic carpal tunnel release was found to be significantly more costly.

Trends in Proximal Interphalangeal and Metacarpophalangeal Joint Arthroplasty Utilization Using Statewide Databases.

Background: Arthritis can have profound debilitating effects on the hand secondary to finger deformities and pain. Arthroplasty of the metacarpophalangeal (MCP) and proximal interphalangeal (PIP) can be performed to reduce pain while maintaining joint range of motion. Methods: We used outpatient surgery registries from the states of California and Florida to assess the trends of arthroplasty across several recent years and to determine if the outcomes differ based on disease etiology. Results: We found that there has been a steady decline in number of MCP arthroplasty procedures performed annually between 2005 and 2011 while PIP arthroplasty procedures peaked in 2007 and have since also declined. There was an overall complication rate of 2.4% and no difference in cardiac, respiratory, deep venous thrombosis and infection between patients with osteoarthritis and other arthritic etiologies. However, the risk of device failure in patients with rheumatoid arthritis is found to be significantly higher than for patients with osteoarthritis (p < 0.01). Conclusions: PIP and MCP arthroplasty are safe procedures with an overall low complication rate. The increased risk of device related complications observed in patients with rheumatoid arthritis can be used to appropriately counsel this patient population regarding post-operative expectations and prognosis.