Scientific Abstract Presentations: Hand Session 3 Thursday, September 26 Thu, Sep 26 5:00-6:00 p.m. PDT

Purpose 

Phalangeal injuries are the most common pediatric hand trauma, but the epidemiology and injury patterns for this group are not well described. This study examines the pediatric hand trauma population and injury characteristics to identify risks associated with phalangeal fractures.   

Methods 

This was a retrospective cohort of pediatric hand trauma patients from 2010-2020. Patients were grouped into phalangeal and non-phalangeal injury cohorts. All charts were abstracted for demographic and clinical details. Population estimates and socioeconomic data were obtained from the United States Census Bureau. Summary statistics were computed, and a binomial regression was used to compute relative risks (RR). Significance was assessed at alpha=0.05. 

Results  

1,311 patients sustained hand trauma, with 690 (52.6%) phalangeal fractures. Demographic factors, including female gender (RR 1.17, CI 1.01-1.36, p=0.03) and age between 6 and 12 years (RR 1.55, CI 1.33-1.80, p<0.001), were associated with increased risk of phalangeal fracture. Median household income between $43,000 and $53,999 was associated with an increased risk of phalangeal injury (RR 1.28, CI 1.02-1.61, p=0.03). The most common mechanisms of phalangeal fracture were sports (n=288, 41.7%), door slam (n=130, 18.8%), falls (n=82, 11.9%), play (n=67, 9.7%), and household mishap (n=63, 9.1%). Sports-related mechanisms (RR 1.68, CI 1.42-2.00, p<0.001) and door slams (RR 1.50, CI 1.15-1.96, p=0.003) were associated with a greater risk of phalangeal fractures. Fingertip injury was the most common soft tissue injury (n=138, 20.0%), and phalangeal fractures were more likely to involve concomitant fingertip injuries (RR 1.18, CI 1.04-1.33, p=0.01). Phalangeal fractures were more likely to be open (RR 1.35, CI 1.26-1.45, p<0.001) or classified as buckle (RR 1.61, CI 1.43-1.82, p=0.02) or Salter-Harris fractures (RR 1.62, CI 1.46-1.81, p<0.001), and were less likely to be displaced (RR 0.83, CI 0.76-0.91, p=0.03). 82 patients (11.9%) required surgery; phalangeal fractures were associated with an increased risk of requiring buddy taping (RR 1.50, CI 1.27-1.77, p=0.001), nailbed repair (RR 1.23, CI 1.03-1.47, p=0.04), and splinting (RR 1.16, CI 1.04-1.29, p=0.008) than other hand fractures.

Conclusions 

This represents the largest reported cohort in pediatric hand trauma to date, and our findings highlight several risk factors for phalangeal fracture. Younger females with fingertip injuries are at highest risk for phalangeal fracture. In addition, phalangeal fractures were more likely to present with complex fracture patterns. These findings can aid in the emergent evaluation of phalangeal fracture, allowing for early referral to hand specialists.

Purpose: Brachial plexus birth injury is a common condition with a wide variation in occurrence globally. The range of potential outcomes spans from spontaneous recovery to incapacitating impairment, notably affecting the shoulder joint in the form of glenohumeral dysplasia (GHD). We propose an algorithm for early correction of GHD in infants diagnosed with brachial plexus birth injury (BPBI) within 12 months of life, recalcitrant to nonoperative care, where there is appropriate time for remodeling after nerve recovery. In this investigation, we evaluate outcomes of patients in which our algorithm was applied.

Methods: According to our algorithm, an intra-operative nerve stimulator is utilized and conduction prior to neurolysis is recorded. Conduction at 0.5 milliamps (mA) is considered normal if the child demonstrates muscle function under anesthesia that corresponds to an induced full range of motion (ROM) against gravity (a simulated "Active Movement Scale" of 7). Shoulder external rotation (ER) is necessary to prevent GHD and must be restored, so this is carefully assessed. Neurolysis of the brachial plexus commences with systematic removal of the cicatrix from the involved aspects of the roots, trunks, divisions, and supraclavicular branches, etc. Nerve stimulation is then repeated. If nerve stimulation at 0.5mA demonstrates full range of ER outside the plane of gravity, no further surgery is performed – we presume the child will recover function. If such motion is achieved with 2mA stimulation or greater, an end-to-side (ETS) nerve transfer of the spinal accessory nerve (SAN) to the suprascapular nerve (SSN) is performed. To proceed with an end-to-end (ETE) nerve transfer of the SAN to the SSN, one of two conditions must be met: either (1) no conduction is achieved after neurolysis at 2mA; or (2) after neurolysis, the patient demonstrates less than full ROM with gravity eliminated at 0.5mA and 2mA.

Results: Twelve patients (average age: 8.5 months) underwent surgery for GHD using the algorithm. The follow up period for the ETS group was an average of 7.9 months (Std dev 2.1), and the follow up period for the ETE group was 13.8 months (Std dev 5.0). At the onset, all patients demonstrated shoulder dysfunction as evidenced by ultrasonography and abnormal AMS scores of shoulder abduction, ER, and forward flexion. All patients failed nonoperative treatment. Five patients underwent ETE nerve transfer, and seven patients underwent ETS SAN to SSN transfer using this algorithm. Ten of twelve patients (83%) had resolution of GHD as determined by postoperative ultrasonography and improved AMS scores. Of the surgical interventions, two ETE nerve transfer patients required reoperation using ER tendon transfers.

Conclusions:
Due to the lack of definitive treatment protocols for GHD ranging from closed reductions and arthroscopic releases to nerve and tendon transfers, this algorithm can assist surgeons in tackling this difficult problem. From our results, 83% of infants treated using this algorithm had resolution of GHD.

Introduction: Ballistic hand fractures (BHF) result from high-velocity, destructive impact, creating complex multi-structure injury patterns which can lead to high non-union rates. We sought to determine factors that may predict these higher complication and non-union rates and assess our management strategy of these fractures. Methods: Patients with BHF from 2016-2023 were identified from an institutional database. Charts and radiographs were reviewed for demographics, smoking status, treatment modality (including use of bone grafting), size of bone gap at the fracture, presence of comminution and, if comminuted, fractures were further categorized by presence and quality of remaining bone stock at the fracture site (ie: (1) complete loss of bone stock, with no bone existing between fracture fragments (NC); (2) partial bony contact (PC); or (3) full bony contact (FC), with comminuted fragments remaining within the gap and >~80% contact with a minimum of ninety-day follow up. Our primary endpoint of interest was union at ninety days. Union was determined based on radiographic and clinical findings at follow-up visits. Univariate and multivariate analysis was performed to determine factors associated with nonunion. Results: Seventy-seven fractures in 48 patients met inclusion criteria, of which 81% (N=62) were comminuted. Fractures were compared by severity of bone loss across the fracture site. A significant difference existed between groups, as measured by maximum bony gap (FC: 1.7 mm vs. PC: 11.3 mm vs. NC: 33.1 mm, p < 0.001). Non-comminuted fractures had an average gap of 0.63 mm. The majority of fractures were treated with Kirschner-wire fixation or immobilization alone, followed by open reduction and external fixation (48.1% vs. 31.2% vs 13.0% vs 7.8%). When treatment modality was compared against severity of missing bone stock, there was no statistical difference, regardless of severity of bone loss, in how fractures were managed (p=0.367). No fractures underwent primary bone grafting. Overall, 22% of fractures achieved union at ninety days (N=17). Of these, 94% (N=16) were either not comminuted or belonged to the FC group. Univariate analysis demonstrated loss of bone stock (NC and PC) was associated with significantly higher rates of non-union compared to FC fractures (90% and 95.2% vs 64.5%, p = 0.018). Additionally smoking and concurrent tendon injury were also associated with non-union (p=0.010, 0.043). On multivariate logistic regression, bone gap (in mm) was an independent predictor of non-union at 90 days (p=0.018).

Conclusions: BHF lead to high rates of non-union, as they are frequently comminuted and have significant loss of bone stock. Due to many factors like soft tissue loss and inadequacy of bone stock, less invasive methods of treatment are frequently used, such as Kirscher-wires or immobilization alone, which ultimately lead to low union rates. We believe surgeons should consider a planned two-stage surgical reconstruction when presented with BHF, as it may alleviate the overall poor union results. Following initial stabilization and adequate soft tissue coverage, we recommend considering a planned second surgery for conversion to internal fixation, with a low threshold to perform secondary bone grafting, especially in the settings of large bony defects.

Introduction: Carpal Tunnel Syndrome (CTS) is the most prevalent entrapment neuropathy affecting the upper extremity, characterized by tingling, numbness, weakness, and pain in the hand and fingers. It impacts approximately 5 to 10% of the general adult population, with annual medical costs totaling up to $2 billion. Despite surgical treatment some patients do not recover full muscle function. This study explores the complex molecular pathways within the abductor pollicis brevis (APB) associated with CTS, including inflammation, muscle atrophy, fibrosis, oxidative stress, and regeneration.

Methods: APB muscle samples were collected from patients undergoing open carpal tunnel release with mild to severe CTS. Total RNA extraction was performed, followed by analysis using quantitative real-time polymerase chain reaction (qRT-PCR).

Results: qPCR analysis unveiled significantly elevated gene expressions of MyoD, Myogenin, Foxo-3, Nf-κB, and Fasn in the severe CTS group compared to both moderate CTS and mild CTS control groups. Additionally, irreversible muscle denervation markers Cystatin C and Decorin were markedly induced in the severe CTS group, with no significant change in the moderate CTS group. Conversely, the atrophy marker gene, Murf1, exhibited high induction in the moderate CTS group, while its expression in the severe CTS group was not elevated suggesting Nf-κB regulated expression of Murf1 may be an early marker of muscle damage.

Conclusion: Understanding the timing and molecular mechanisms responsible for muscle loss in CTS allows for the identification of potential biomarkers and therapeutic targets to reverse muscle damage as well as helps guide timing for surgical release to avoid irreversible muscle loss.

Introduction: Trapeziometacarpal osteoarthritis (TMOA) is a common form of hand osteoarthritis that can be treated using several surgical and non-invasive modalities. Regenerative medicine has been widely regarded as a promising therapy option for many medical conditions. This research aimed to evaluate the effectiveness of autologous fat graft injections in improving pain relief, function, and quality of life in patients with TMOA. Methods: In line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic literature search was conducted using Cochrane, MEDLINE, Google Scholar, and EMBASE to identify relevant studies. Extracted data focused on measurements of pain relief, treatment complications, and indicators of improved hand function. A meta-analysis using a single-arm design was performed with the STATA software, using random effects model with a 95% confidence interval. Results: A total of 341 studies were identified for screening. Six studies were eligible for inclusion in the review. After 12 months of follow-up, autologous fat grafting led to a statistically significant reduction in pain (p = 0.00). However, changes in grip strength were not statistically significant (p = 0.15). Out of 192 total cases, 16 (8.0%) experienced complications requiring additional surgery. Conclusion Autologous fat grafting significantly relieves pain in TMOA, but functional improvements are not significant, and 8.0% need surgical intervention for complications. More rigorous, long-term RCTs are essential to evaluate its efficacy and safety against standard TMOA treatments.

Introduction: Lymphangiosarcoma (LAS) is an aggressive cutaneous angiosarcoma, often occurring in association with chronic lymphedema. While LAS most often diagnosed in the upper extremities following axillary lymph node dissection or local radiation therapy for breast carcinoma, it may also affect other organs. However, due to its rarity, neither pathogenesis nor a standard treatment strategy has been established. This retrospective analysis aims to contribute insights into the management and outcomes of lymphangiosarcoma through a comprehensive review of cases from a single institute. Methods: A retrospective medical record review of patients with a diagnosis of lymphangiosarcoma from 1976 to 2022 was done. Clinical details including demographics, history, risk factors and comorbidities, operative course, postoperative complications, outcomes, and recovery were recorded. Descriptive analysis was done on the data points.
Results: 37 patients were included in the final analysis. The mean age at the diagnosis of this patient population was 61.6 ±16.6 years, with a mean BMI of 29.7±8.6 kg/m2. 11 (29.7%) patients were male. Hypertension was noted in 21 out 32 cases, cardiovascular disease in 7 out of 33 cases, and chronic lymphedema in 29 out of 35 cases where data were available. LAS location included 15 cases (40.5%) in the upper extremities alone, 12 cases (32.4%) in the lower extremities alone, and 10 cases (27.0%) in other areas. Among these patients, 17 out of 37 (45.9%) had history of prior surgeries, with 8 out of 29 (27.6%) received prior chemo and 17 out of 33 (51.5%) underwent prior radiation where data was available. Surgical intervention was done in 31 out of 37 (83.8%) diagnosed cases, with a median time from diagnosis to surgery of 29 days (range: 2-1246). Additionally, chemotherapy and radiation therapy were administered in 19 cases (51.4%) and 9 cases (24.3%), respectively. The median survival time from date of diagnosis to either death or available last follow up is 28.4 months (range: 0.2-563.2), with recurrence of 24 (64.9%) out of 37 cases. Conclusion: In conclusion, this study highlights the diverse management approaches and outcomes of Lymphangiosarcoma (LAS) at our institute. With no standardized treatment protocol due to its rarity, surgical intervention emerged as a prominent therapeutic modality, with proportion of patients undergoing chemotherapy, and radiation. The median survival time highlights the challenges in managing this condition, with a notable recurrence rate.

Introduction and Objective:

Extradigital glomus tumors, rare neoplasms found primarily in digits, present significant diagnostic challenges when occurring in upper extremities, often leading to misdiagnoses and delayed treatment. Characterized by symptoms like pinpoint pain and cold sensitivity, they mimic other vascular or neural pathologies. This study aims to elucidate the diagnostic intricacies of extradigital glomus tumors.

Methodology:

A systematic review was conducted using PubMed and Google Scholar, focusing on literature up to April 1 2023. We included 37 studies, primarily case reports and retrospective reviews, emphasizing English-language articles on extradigital glomus tumors in the upper extremity.

Results:

The total sample size was 136, with the average symptom duration before treatment or diagnosis being nearly six years. The most common locations were forearm (n=39, 28.6%) and lower extremity (n=28, 20.5). The studies revealed a high rate of misdiagnosis, with the two largest studies showing misdiagnosis rates of 48% and 84%. Common symptoms included pinpoint tenderness (86%) and pain (70%). Additional symptoms like painful swelling, hand clumsiness, and night-time pain were reported. Diagnostic imaging varied; MRI was the most common modality. Immunoreactivity studies predominantly showed SMA positivity (81.25%).

Conclusion:

Extradigital glomus tumors are more prevalent than previously recognized, with a significant likelihood of misdiagnosis. This misidentification often leads to prolonged symptomology. While imaging is helpful, it frequently falls short in specific diagnosis, highlighting the importance of clinical suspicion and thorough diagnostic approaches. Our study underscores the need for greater awareness and a multidisciplinary strategy in diagnosing and treating extradigital glomus tumors.

Introduction. While replantation can significantly improve a patient's quality of life following upper extremity amputation, it can be a difficult surgery requiring advanced microsurgical skill. Previous studies have shown a decrease in the rate of replantation following upper extremity amputation. While it is known that surgeons are less likely to choose to replant, the factors that determine which patients are selected for replantation have not been adequately investigated. Purpose. This study aims to analyze the demographic, geographic and temporal factors impacting the decision to replant after upper extremity amputations. Methods. The National Inpatient Sample (NIS) was queried from 2016 to 2020. ICD-10 diagnosis codes for complete and partial traumatic amputations of the upper extremity were used to identify cases. Amputations at level of the upper arm, the forearm, the wrist, the hand and the digits were included. ICD-10 procedure codes were utilized to differentiate between revision amputations and replantation or revascularization. Results. A total of 3,760 amputations occurred from 2016 to 2020. Of the total amputations, 117 (3.11%) were above the elbow, 90 (2.39%) were at the forearm, 96 (2.55%) were at the wrist, 612 (16.28%) were in the hand, and 2,845 (75.66%) were of the digits. 2,468 (65.64%) of the amputations were classified as partial, and 1,292 (34.36%) were classified as complete. Replantation was attempted in 1,331 (35.40%) of cases. The rate of replantation did not change significantly over time (p = 0.587). Upon univariate analysis, rates of replantation differed significantly across hospital census regions (p = 0.004), with New England performing the most replantations (46.53%), and the West South Central performing the least (30.98%). Rates of replantation also decreased significantly in non-white patients (p < 0.001), patients in lower income quartile (p < 0.001), patients on Medicare or Medicaid (p < 0.001), and in patients living in more rural areas (p = 0.001). Similar results were found upon multivariate analysis. Patients in a higher income quartile (Odds ratio (OR): 1.15, p < 0.001, 95% confidence interval (CI): 1.07 – 1.22), complete amputations (OR: 1.22, p = 0.007, 95% CI: 1.06 – 1.42), and patients with private or self-pay insurance (OR: 1.05, p = 0.007, 95% CI: 1.00 – 1.09). Additionally, patients from more rural areas (OR: 0.94, p = 0.004, 95% CI: 0.90 – 0.98), non-white patients (OR: 0.94, p = 0.032, 95% CI: 0.88 – 0.99), and older patients (OR: 0.99, p < 0.001, 95% CI: 0.98 – 0.99). Hospital census region (p = 0.658) and the level of injury (p = 0.379) did not significantly impact the probability of replantation. Conclusion. While rates of replantation have remained steady over time, there are significant disparities in which patients undergo replantation. Non-white patients, older patients, patients from rural areas, patients from lower income quartiles, and patients on Medicaid or Medicare were less likely to undergo replantation.

Purpose: The etiology of limb reduction defects remains unclear. Maternal ultraviolet (UV) exposure has not been shown to influence the risk of limb reduction defects in newborns. This study investigated the association between prenatal UV dose and the risk of limb reduction defects in the United States (U.S.)

Methods: The U.S. 2014 and 2015 Natality Data were utilized (n = 7,986,908). Mean daily county-level population-weighted erythemally-weighted daily UV dose was calculated over two specific periods for each live birth, namely the first trimester and the three months prior to conception. Multivariable logistic regressions controlled for household demographics, prenatal characteristics, infant characteristics, and socioeconomic factors.

Results: Of 7,693,026 live births included, 1044 (0.014%) had limb reduction defects. Higher mean daily UV dose during the three months prior to conception was associated with statistically significantly lower odds of limb reduction defects (aOR = 0.99 [0.99, 0.99], p < 0.001). The odds of limb reduction defects were independent of the mean daily UV dose during the first trimester (aOR = 0.99 [0.99, 1.00], p = 0.373). The models suggested several other risk factors for limb reduction defects, including lower maternal education level (aOR = 1.34 [1.07, 1.67] for high-school non-graduates and below compared with high-school graduates/GED holders, p = 0.010), maternal pre-pregnancy diabetes (aOR = 2.29 [1.43, 3.67], p < 0.001), presence of other congenital disorders (aOR = 31.2 [24.9, 39.1], p < 0.001), and forms of government insurance as the payment method for delivery (aOR = 1.26 [1.04, 1.53] for Medicaid compared to private insurance, p = 0.019; and aOR = 1.89 [1.28, 2.79] for Indian Health Service/CHAMPUS/TRICARE or other government insurance programs compared to private insurance, p = 0.001).

Conclusions: Higher daily maternal dose of UV during the three months prior to conception, but not during the first trimester, was associated with decreased odds of limb reduction defects after controlling for a number of covariates. Our study suggested that UV may be implicated in limb development in an indirect fashion via prenatal events leading up to the conception of the embryo, but not directly during fetal development per se. The analysis also indicated proxies of lower socioeconomic status as risk factors for limb reduction defects. Further studies are needed to confirm the associations and elucidate their mechanisms.

Purpose: Free functional gracilis muscle transfer (FFGT) is a useful option for reconstruction of elbow flexion following brachial plexus injury (BPI) presenting late or with no usable nerve donors. In this systematic review and meta-analysis, we aimed to investigate variables associated with superior outcomes. Specifically, the efficacy of single vs double FFGT and the choice of donor nerve for neurotization of the FFGT were evaluated.

Methods: Meta-analysis was conducted using a random effects model using Review Manager software (RevMan) 5.4 and OpenMeta Analyst of studies that provided postoperative Medical Research Council (MRC) grade for elbow flexion, DASH, and VAS scores, quantitative elbow flexion strength, and range of motion (ROM). A meta-regression analysis was performed to identify factors associated with improved outcomes.

Results: Thirty-seven studies, with 1607 patients, were analyzed. Single FFGT was reported in 34 studies (n=1398), and double FFGT was reported in 10 studies (n=209). The mean follow-up duration was 37.3 ± 21.1 months. Following single FFGT, 75.4% and 48.9% achieved MRC grades >3 and >4, respectively. Following double FFGT, 100% achieved MRC grade >3 and 62.7% >4. Subgroup analysis showed a significant difference in MRC grade >3 and >4, favoring double FFGT over single FFGT (P<0.05). Overall, FFGT innervated by spinal accessory nerve (SAN) had significantly better recovery of MRC grade >3 (P<0.05) compared to other innervating nerves. Subgroup analysis comparing single and double FFGT innervated by SAN showed no significant difference in recovery of elbow flexion. Meta-regression analysis showed a significant negative correlation between the patient's age and the probability of achieving an MRC grade of > 3 and 4 (P<0.05). The pooled mean postoperative DASH score (n=8 studies, 671 patients) for single FFGT was 37.8 (95% CI: 33.67, 41.98), and a random effects meta-analysis of 27 patients from 3 studies showed a significant improvement from the preoperative DASH score with a mean difference of -13.86 (95% CI [-23.57, -4.15]; P<0.05). The mean postoperative VAS score (n=5 studies, 576 patients) was analyzed as 3.38 (95% CI: 2.96, 3.80). A meta-analysis of 2 single FFGT studies comparing postoperative and preoperative VAS scores showed a significant improvement after the procedure (Mean Difference: -0.88, 95% CI [-1.55, -0.21]; P<0.05). Mean elbow flexion strength after single FFGT (n=4 studies, 210 patients) was analyzed to be 2.60 kg (95% CI [1.94,3.27]). The mean range of motion of elbow flexion (ROM) of 609 patients (n=9 studies) undergoing single FFGT was 94.3 degrees (95% CI: 87.8, 100.8), whereas, for patients undergoing double FFGT, it was 118.7 degrees (95% CI:113.6, 123.8) with significant subgroup differences between the two procedures, favoring double FFGT (P<0.05).

Conclusion: FFGT innervated by SAN had the best functional outcomes. Double FFGT was superior overall to single FFGT. Comparing outcomes specific to single/ double FFGT innervated by SAN, there was no significant difference, showing that the choice of donor nerve is most important. Increasing age was a significant risk factor for poorer outcomes.