Scientific Abstract Presentations: Hand Session 1 Thursday, September 26 Thu, Sep 26 9:45-11:45 a.m. PDT

Abstract Purpose The advantages of performing an epitendinous repair have been well described, and include greater tensile strength, greater resistance to gap formation, a smoother and less bulky repair, fewer adhesions, fewer ruptures, and better clinical outcomes (1,2). A recent survey found that 97% hand surgeons in the United States employ an epitendinous repair in addition to the core suture repair for zone II flexor tendon lacerations (3). The biomechanical characteristics of epitendinous repairs have been studied. However, there is little information about the role of suture diameter and the number of crossing strands in epitendinous repairs. The purpose of this study is to determine whether the number of crossing strands or suture diameter affect the biomechanical characteristics of an epitendinous repair. In this study, we performed a biomechanical comparison of epitendinous flexor tendon repairs using a simple running technique with varying suture caliber and numbers of passes.

Methods Thirty flexor pollicius longus (FPL), flexor digitorum profundus (FDP), and flexor digitorum superficialis (FDS) tendons were harvested from three cadavers and transverse zone 3 flexor tendon lacerations were produced. Tendons were repaired with only an epitendinous suture (no core suture) in 3 groups: 6-0 prolene with 6 passes, 5-0 prolene with 6 passes, or 5-0 prolene with 8 passes. Epitendinous repair strength was tested using an Instron materials testing machine.

Results The use of 8 passes had significantly greater maximum load than 6 passes (21 +/- 7 N vs. 14 +/- 5 N, p < 0.05), as well as significantly greater 2 mm gap resistance (8 +/- 6 N vs 4 +/- 2, p < 0.05). Although 5-0 suture had a higher average maximum load than 6-0 suture, after adjusting for multiple hypotheses testing, this difference did not reach statistical significance (14 N +/- 5 vs. 10 N +/- 3, p = 0.10). Failure mode for all groups was most often suture tear-through.

Conclusion When considering an epitendinous suture to augment a flexor tendon repair, 8 passes provides almost 50% more epitendinous repair strength and greater 2 mm gap resistance than 6 passes when using 5-0 prolene. The choice of suture caliber may also have an impact on the strength of the repair, but more research is needed to determine if this impact is significant. This study demonstrates that a 5-0 epitendinous repair with 8 crossing strands has substantially greater strength and gap resistance when compared with 6 crossing strands.

References 1. Merrell GA, Wolfe SW, Kacena WJ, Gao Y, Cholewicki J, Kacena MA. The effect of increased peripheral suture purchase on the strength of flexor tendon repairs. J Hand Surg Am. May 2003;28(3):464-8. doi:10.1053/jhsu.2003.50074 2. Diao E, Hariharan JS, Soejima O, Lotz JC. Effect of peripheral suture depth on strength of tendon repairs. J Hand Surg Am. Mar 1996;21(2):234-9. doi:10.1016/s0363-5023(96)80106-7 3. Gibson PD, Sobol GL, Ahmed IH. Zone II Flexor Tendon Repairs in the United States: Trends in Current Management. J Hand Surg Am. Feb 2017;42(2):e99-e108. doi:10.1016/j.jhsa.2016.11.022

Background The Resource-Based Relative Value Scale and its working relative value units (wRVUs) is one model for surgeon compensation. The number of wRVUs per Current Procedural Terminology (CPT) code has been negotiated considering the degree of technical skill required, expected time to completion, mental stress, and physical labor associated with each procedure.1 Some studies have shown that acute surgeries are reimbursed at a lower rate than elective surgeries despite increased patient length of stay, more complications, and subsequently increased physician attention.2 In this study, we aimed to compare the wRVU/min rate of elective hand surgeries as compared to traumatic hand surgeries.

Methods We included consecutive elective and traumatic hand cases from a single academic institution from October 1, 2015 to July 1, 2023. Demographic data were collected in addition to CPT code, incision start/stop time, and wRVU amount. Cases with more than one CPT code assigned or CPT codes logged fewer than 10 times total were excluded from the dataset. Outliers greater than 2.5 standard deviations from the mean incision start/stop time per procedure were also excluded. Average RVU/min rates were calculated by procedure, specialty, and case type (trauma or elective) and weighted to better reflect the case mix. All averages were calculated as medians. Medians were compared using the Mann-Whitney-U test.

Results A total of 9,977 elective cases and 2,666 trauma cases were included. The dataset consisted of 10 elective and 16 trauma procedures. Elective cases had an average wRVU/min rate greater than twice the rate for trauma cases (0.532 RVU/min vs. 0.191 RVU/min, p<0.001). "Endoscopic release of the transverse carpal ligament" (CPT 29848) was the elective procedure with the highest relative value rate at 0.799 wRVU/min, followed by "Fasciectomy, Palm Only" (CPT 26121) and "Carpal Tunnel Release, Open" (CPT 64721) at 0.455 and 0.414 wRVU/min, respectively. "Percutaneous skeletal fixation of distal radial fracture or epiphyseal separation" (CPT 25606) was the trauma procedure with the highest relative value rate at 0.396 RVU/min, followed by "Intra-articular DRF Repair, Open, 2 Fragments" (CPT 25608) at 0.213 wRVU/min and "Percutaneous Skeletal Fixation of Unstable Phalangeal Fracture, Each" (CPT 26727) at 0.208 wRVU/min.

Conclusion Despite the complexity and urgency of trauma procedures, we found a significantly lower average wRVU/min rate for traumatic hand surgeries as compared to elective hand surgeries.

References: 1. Dibbs RP, Skochdopole A, Reul RM Jr, et al. Correlation between Relative Value Units and Operative Time for Flap-Based Reconstruction Procedures. Plast Reconstr Surg. 2023;151(2):299e-307e. doi:10.1097/PRS.0000000000009859 2. Rodriguez JL, Polk HC Jr. Profitable versus unprofitable expansion of trauma and critical care surgery. Ann Surg. 2005;242(4):603-609. doi:10.1097/01.sla.0000184222.75170.ac

Objective: The objective of this work is to evaluate existing literature on novel treatments in order to identify the most promising approaches and highlight their potential implications in clinical practice. Methods: A systematic review and metaanalysis was conducted on studies reporting on De Quervain Tendonitis, following the PRISMA guideline statement. Data was extracted with a focus on overall success of treatment, success after multiple interventions within the time of study, and incidence of surgical interventions after treatment failure. Statistical analysis of single-arm studies was conducted using OpenMetaAnalyst and double-arm studies using RevMan, both with random-effects model implemented. Results: 12 studies evaluated the effectiveness of corticosteroids and the overall success rate was high with an incidence of improvement reaching 81.9% (95% CI: 75.0% - 88.9%). It was also found upon subgroup analysis that an increased number of injections is associated with a higher

treatment success rate. The implementation of ultrasound guidance for injections increased the improved rate to 91.7% (95% CI 86.1% - 97.3%). Using splinting in combination with 1 or 2 corticosteroid injections yielded an improvement rate of 64.2% (95% CI 45.5% - 82.9%). Analysis revealed that corticosteroids were a more effective treatment for De Quervain's disease over splinting, with a significant difference (P<0.00001, CI=3.16 - 15.55). 11 studies investigated surgical intervention after treatment failure and found that the incidence of surgery due to treatment failure was very low, at 11.4% (95% CI 6.4% to 16.3%). The incidence of surgery after a combination of splinting and injections was higher at 18.5% (95% CI 4.6% to 32.5%). A subgroup analysis of success after multiple corticosteroid injections demonstrated that the incidence of improvement for the two-injection approach was 13.1% (95% CI 5.5% to 20.6%), whereas the three-injection approach showed a higher incidence of improvement at 30.4% (95% CI 25.2% to 35.6%). Conclusion: The incidence of improvement in De Quervain disease following a combination of non-invasive management approaches is robust. In particular, repeated steroid injections with ultrasound guidance in combination with splinting decreases the need for surgical intervention.

Purpose: The objective was to evaluate racial/ethnic differences in analgesic administration for pediatric patients undergoing upper extremity procedures in ED.

Methods: A retrospective review of pediatric patients aged 12 years and younger who underwent upper extremity procedures by a plastic surgery resident in the ED between June 2015 and October 2023 was conducted. Included patients had the following upper extremity procedures: laceration repair, nailbed repair, reduction, incision and drainage, and amputation revision. Data on patient demographics included age, gender, race, ethnicity, and primary language. Pain management data collected included receipt of pain medications during the ED admission, procedural sedation, local anesthetic, and pain medication recommendations at discharge. Multivariate logistical regressions adjusting for age, gender, and primary language were used to elucidate the relationship between race/ethnicity and the receipt of pain management.

Results: A total of 403 pediatric patients who underwent an upper extremity procedure by a plastic surgery resident in the ED were identified (mean age 6.23 ± 3.74 years). There were 260 (64.5%) male and 143 (35.5%) female patients and 194 (48.1%) non-Hispanic White, 54 (13.4%) non-Hispanic Black, 115 (28.5%) Hispanic, 7 (1.7%) Asian, and 33 (8.2%) "other race" patients. A total of 258 (64%) of patients received oral or intravenous pain medications during their ED admission, including ibuprofen, acetaminophen, ketorolac, or narcotics. Local anesthetic was utilized for 353 (87.6%) of patients and procedural sedation, either ketamine, midazolam, or both, was given to 281 (69.7%) of patients. Pain management recommendations for acetaminophen, ibuprofen, or narcotics at discharge were included in the medical chart for 328 (81.4%) of patients, either in the plastic surgery progress note or ED after visit summary documentation, which is provided to the patient at discharge.

Older patients had significantly lower odds of receiving procedural sedation (OR=0.72 [95% CI: 0.66–0.77]; p<0.0001). Female patients had higher odds of receiving pain management recommendations at discharge compared to male patients (OR=1.84 [1.05–3.34]; p=0.03). While there were no significant differences in receipt of pre-procedural analgesic administration, local anesthetic, and discharge analgesic recommendations between racial/ethnic groups, non-Hispanic Black patients had significantly lower odds of obtaining procedural sedation compared to non-Hispanic White patients (OR=0.42 [0.20¬–0.87]; p=0.02).

Conclusion: In the ED of our institution, there is a discernible disparity in the administration of appropriate pre-procedural sedation among non-Hispanic Black pediatric patients. This observation suggests a potential bias in pediatric pain management strategies. To counteract this, we recommend the consideration of institution-level policies that advocate for 'opt-out' sedation protocols to ensure equitable pain management across diverse patient populations. We encourage further studies examining sedation receipt in other surgical procedures in the ED and for other institutions to investigate whether disparities exist in pediatric pain management in their hospitals.

Purpose This study investigated how social vulnerability index (SVI) influences the treatment outcomes of patients with distal radius fractures (DRF) undergoing open reduction internal fixation (ORIF).

Methods Patients presenting with a DRF (ICD10-S52.5) were identified in the State Emergency Department Database for Florida, New York, and Wisconsin. Follow-up visit data were compiled from the respective State Ambulatory Surgery and Services Databases and State Inpatient Databases. Treatments were classified as no treatment, closed, or open (ORIF). Patients were assigned SVI values based on ZIP codes, and those with ambiguous SVI values were excluded. Multivariate logistic regression was used to assess the impact of overall SVI, as well as its four component themes (Racial and Ethnic Minority Status [RACE]; Socioeconomic Status [SES]; Household Characteristics [HOUSEHOLD]; and Housing Type & Transportation [TRANSPORT]), on the odds of open treatment and post-operative complications for patients who received closed or open treatment. Resultant odds ratios can be interpreted as a comparison between a patient from the most vulnerable ZIP code (SVI = 1) versus a patient from the least vulnerable ZIP code (SVI = 0).

Results From 2015 to 2020, among 68,986 patients (average age 47.1 years; 36.2% male), 73.1% received no initial treatment, 24.3% closed treatment, and 2.6% ORIF. Most patients continued with no treatment (57.4%, n = 39,615),16.5% (11,405) with closed treatment and 26.0% (17,966) with ORIF . On multivariate logistic regression, higher RACE SVI increased the likelihood of ORIF (OR = 5.1), while high SES, HOUSEHOLD, and TRANSPORT SVI decreased it. Higher overall SVI was linked to an increased risk of wrist stiffness and ED revisits. SES SVI was inversely related to wound dehiscence, while HOUSEHOLD SVI was positively related to both wound dehiscence and surgical site infections. Wrist stiffness was positively related to SES and TRANSPORT SVI but negatively to RACE and HOUSEHOLD SVI. Lastly, overall SVI was not associated with DRF open treatment.

Discussion SVI's components, rather than overall SVI, predict the type of DRF treatment and vary in association with surgical outcomes. Patient geography can greatly impact DRF outcomes but requires careful examination to isolate relevant causative factors.

Purpose Ulnar nerve decompression surgery is often a non-emergent procedure, giving surgical care teams the ability to optimize patient profiles prior to surgery. Preoperative hematocrit, albumin, and creatinine levels have been identified as predictors of increased morbidity in surgical patients. The present study aims to analyze the impact of preoperative hematocrit, albumin, and creatinine on short-term outcomes after ulnar nerve decompression surgery.

Materials and Methods Ulnar nerve decompression surgeries (CPT 64718) were queried from the American College of Surgeons National Quality Improvement Program (NSQIP) database from 2005-2020. Primary variables of interest were preoperative serum hematocrit, albumin, and creatinine values. For each included case, a set of demographic, medical, and operative characteristics, alongside the latest preoperative serum lab value within 90 days preoperatively for hematocrit, creatinine, and albumin, was extracted. Outcomes included health resource utilization metrics, medical complications, and wound complications. Bivariate analyses, followed by a multivariate logistic regression, were performed. Outcomes with significance on both tests were analyzed using an Area Under the Receiver Operating Characteristic Curve (AUC) and cutoff analysis.

Results In total, 945 patients with hematocrit, 419 patients with albumin, and 938 patients with creatinine were included. Increased hematocrit independently decreased the odds of return to the operating room (aOR: 0.899; p=0.025), medical complications (aOR: 0.871; p=0.003) and extended length of stay (aOR: 0.952; p=0.048). Among male patients, hematocrit lab values of ≤ 39.2% (AUC: 0.68, p<0.001) for extended length of stay, ≤ 40.9% (AUC: 0.68, p=0.018) for return to operating room, and ≤ 38.1% (AUC: 0.72, p=0.012) for medical complications were identified. Among female patients, hematocrit cutoff values of ≤ 38.1% (AUC: 0.59, p=0.013) for extended length of stay and ≤ 35.4% for medical complications (AUC: 0.77, p<0.001) were identified. No significant relationship was identified when analyzing serum albumin or creatinine on multivariate analysis.

Conclusions Patients with increased preoperative hematocrit experienced lower odds of postoperative morbidity. These findings can aid in optimal timing of ulnar nerve decompression surgery. Moreover, this knowledge empowers patients to engage in informed discussions with their healthcare providers, fostering a collaborative approach to treatment planning and enhancing the likelihood of favorable surgical outcomes.

Purpose: Vascularized nerve grafts (VNG) have been proposed as encouraging alternatives to conventional nerve grafting, yet there is ongoing debate regarding the clinical advantages of the approach compared to standard grafting. This review aims to gather and analyze reported cases of upper extremity nerve repair using VNGs documented in the published literature. Methods: In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA) Pubmed/MEDLINE, Embase and Cochrane were searched. Inclusion criteria for this review were: 1) human subjects; 2) describing a vascularized nerve grafting procedure or suggesting a nerve and vascular supply for a potential vascularized nerve graft; 3) upper extremity nerve repair in clinical studies. Results: Data was extracted from 45 clinical studies. Of 535 patients, the most common injury pattern was root avulsion and rupture (88.7%). The most utilized VNG was the ulnar nerve (72.8%), followed by nerve to long head of triceps (8.8%), sural nerve (8.2%), dorsal digital (3.0%), deep peroneal (2.7%) and other nerves (4.6%); most common recipients were median (57.6%), axillary (12.5%), musculocutaneous (11.9%), digital (10.6%) and other nerves (7.4%). Between patients who had medical research council scale scores, 69% had functional (M3 and above) motor and 72.7% sensory (S3<) recovery. In studies comparing vascularized grafting to standard grafting, 88% of VNG case outcomes showed added advantage. Conclusion: Pooled data from systematically reviewing studies on non-vascularized nerve autografts, indicate that 71.8% of recipients reached S3 and above and 36.3% achieved M4 [1]. As for VNGs, 72.7% attained S3 and above, and 36.1% reached M4, which is comparable to non-vascularized grafts, bearing in mind that nerve gaps bridged by the mentioned non-vascularized autografts did not exceed 7cm and those bridged by VNGs ranged from 2 to 51cm, with mean length of 14.7cm. VNGs were also more likely to be used for poorly vascularized recipient beds. Overall, VNGs can increase the odds of functional gain in challenging conditions such as large nerve gaps, nerve avulsions, ruptures, scarred and irradiated beds. With the exception of well-known VNG options, literature on alternative VNGs is largely confined to case reports and series; with additional published cases, outcomes and basic science research needed to establish the role of VNGs in nerve repair. 1. Lans J, Eberlin KR, Evans PJ, Mercer D, Greenberg JA, Styron JF. A Systematic Review and Meta-Analysis of Nerve Gap Repair: Comparative Effectiveness of Allografts, Autografts, and Conduits. Plast Reconstr Surg. 2023;151(5):814e. doi:10.1097/PRS.0000000000010088

Introduction: Breast cancer-related lymphedema is one of the most common causes of upper extremity lymphedema, with an overall incidence of 17% in breast cancer survivors (1). Previous research has determined many risk factors, including age > 65, obesity, radiation, chemotherapy, axillary node dissection, hypertension, and taxane therapy (2). However, additional research is needed to investigate other potential risk factors, including the usage of Calcium Channel Blockers (CCB). By identifying individuals at the greatest risk, it may be possible to enhance overall outcomes. This study aims to assess the relationship between the use of CCB with upper extremity lymphedema and cellulitis in postmastectomy patients. Methods: This study was conducted with anonymized data accessed via the TriNetX platform, a database providing patient data from 75 healthcare organizations (HCOs). The analysis was performed at HCOs, with only aggregated results returned to the platform. We utilized ICD-10, CPT, and TNX-curated codes to build our cohorts. The analysis was conducted in February 2023 using the analytic tools built into the TriNetX platform. We compared mastectomy patients who underwent CCB therapy within 1 year of surgery (cohort 1) with those who did not (cohort 2). The cohorts were matched on age at Index, sex, race, ethnicity, BMI, diabetes mellitus, hypertension, cellulitis, acute lymphangitis, heart failure, chronic kidney disease, cancer, lymphadenectomy, type of mastectomy, type of breast reconstruction, radiotherapy, taxanes, and beta-blockers. The outcomes of interest were the development of lymphedema and the development of cellulitis in the first three years after mastectomy. The Risk Ratio (RR) with a 95% CI was calculated to assess cohort differences after matching. Results: From 2003 to 2017, a total of 69,816 mastectomy encounters met our eligibility criteria. After propensity score matching, the patient count for each cohort was 8,779. The mean age at Index for cohorts 1 and 2 was 65.5 (SD 11.9) and 66.0 (SD 11.6), respectively. Moreover, 98.2% of the population was female, 63.5% was white, 800 patients developed lymphedema, and 2,263 patients developed cellulitis. The following patient characteristics showed statistical significance between cohorts: age at Index (p=0.006), hypertension (p=0.01), heart failure (p=0.04), diuretic use (p<0.001), and BMI (p=0.005). The cohort 1 displayed an increased risk of cellulitis (RR 1.105, 95% CI 1.023- 1.194, P= 0.011). However, there was no significant difference in the development of lymphedema between the cohorts (RR 0.956, 95% CI [0.835 - 1.095], [p=0.51]). Conclusion: Our results suggest that the use of CCB within a year of mastectomy is an independent risk factor for cellulitis. The use of CCB within a year of mastectomy is not associated with the development of BCRL. More studies accounting for the unbalanced variables between the cohort are needed to support these results and eliminate potential confounders.

References DiSipio T, Rye S, Newman B, Hayes S. Incidence of unilateral arm lymphoedema after breast cancer: a systematic review and meta-analysis. Lancet Oncol. 2013 May;14(6):500-15. doi: 10.1016/S1470-2045(13)70076-7. Epub 2013 Mar 27. PMID: 23540561. Basta MN, Wu LC, Kanchwala SK, Serletti JM, Tchou JC, Kovach SJ, Fosnot J, Fischer JP. Reliable prediction of postmastectomy lymphedema: The Risk Assessment Tool Evaluating Lymphedema. Am J Surg. 2017 Jun;213(6):1125-1133.e1. doi: 10.1016/j.amjsurg.2016.08.016. Epub 2016 Sep 7. PMID: 27745890.

Purpose At-home management of upper extremity lymphedema can present challenges for patients who have limited range of motion or inability to execute self-manual lymphatic drainage (MLD). Older generation pneumatic compression devices (PCD) have been associated with complications such as worsening edema, lack of efficacy, and difficulty with device usage. Furthermore, patients who require PCD face difficulties obtaining insurance authorization for these devices. In this pilot study, we sought to understand whether the Flexitouch System (FT), can provide symptomatic relief, improve lymphatic drainage, and to assess lymphatic flow immediately before and after pneumatic compression using ICG imaging.

Materials and Methods Patients were injected with Indocyanine green (ICG) in the dorsal, subdermal webbed space, and mapped with SPY. SPY mapping was performed for patients with upper extremity stage II lymphedema secondary to breast cancer (BCRL) before and after 30 minutes of treatment with Flexitouch+ with Comfort East Garments Upper Extremity Jacket (Tactile Medical, Minneapolis, MN). Patient histories were examined via retrospective chart review. Pre and post treatment SPY imaging was filmed and interpreted by a single reviewer. Patient reported outcomes were measured using the Lymphedema Life Impact Scale (LLIS).

Results 13 limbs across 8 female patients (4 healthy arms, 9 arms with lymphedema) were included in our analysis. 7 patients had unilateral lymphedema and 1 patient had bilateral lymphedema. 5 patients were injected bilaterally (10 arms), and 3 patients were injected unilaterally (3 arms). Patients were 60.18+/-21.96 years old at the time of injection, and 75% (6 patients, 10 arms) had received surgical intervention to treat lymphedema 1.44+/-1.48 years prior to injection. Patients had an average of 1.75+/-1.49 surgical procedures to treat lymphedema: 4 patients had liposuction, 4 patients had VLNT, 4 patients had LVA, 2 patients had Biobridge placement, and 1 patient had LYMPHA. Patients had used a pneumatic compression device for an average of 185.43+/-152.70 weeks, at a frequency of 6.75+/-3.56 times per week. After 30 minutes of therapy, 100% (13) arms showed an improvement in lymphatic flow as measured by proximal migration of contrast. 100% (4) of healthy arms, and 66.7% (6) of arms with lymphedema showed an increase in linear lymphatic channels. ICG traveled the same speed in healthy arms as arms with lymphedema in 50% (2) patients with unilateral lymphedema who received bilateral injections. Patients reported significant improvement in limb pain (p=0.01), heaviness (p=0.04), tightness (p=0.04) following FT therapy independent of surgical intervention or lymphedema laterality.

Conclusion Our study showed enhancement in lymphatic flow in healthy limbs, limbs with lymphedema, and preservation of lymphatic drainage in those who have had lymphedema prevention surgery (LYMPHA) after only 30 minutes of pneumatic compression with the Flexitouch System. Furthermore, imaging suggests FT treatment may improve lymphatic flow speed to arms with lymphedema. Patient satisfaction data shows FT provides relief in upper extremity lymphedema symptoms. Future studies should examine the role of long-term FT usage and its effects on LV, BIS, and quality of life in upper extremity lymphedema patients compared with other existing pneumatic compression devices.

Introduction Dermal regeneration matrix (DRM) has been demonstrated to be safe and beneficial in improving functional outcomes for the management of acute hand burns. DRM followed by split thickness skin graft (STSG) allows for a two-stage reconstruction for most operative hand burn injuries. Our site routinely implements a 3-staged approach with cadaver allograft at the first stage. The aim of this study is to compare the surgical and functional outcomes of 2-staged DRM reconstruction and 3-staged reconstruction. Methods A retrospective study was conducted to review surgical and functional outcomes of patients treated for hand burns. All patients seen from April 2009 and December 2022 with hand burns, for who objective hand measurements were available, were considered for the study. Results From 2009 to 2023, 227 patients were treated for hand burns. Of them, 44 patients had objective hand measurements and were included in the study. Patient (77.3% males,22.7% females) mean age was 39.3±16.1 and the mean BMI was 27.1±6.4. Patients suffered from 1.3±1.4 comorbidities. Patients were followed for 22.0±25.0 months. Most burns were full thickness (97.7%, n=43) and involved 15.3±16.7% TBSA. Patients suffered thermal injuries (93.2%, n=41) and electrical burns (6.8%, n=3). Many patients had bilateral hand involvement (52.3%, n=23). Most cases (n=27) received a 3-staged approach with cadaver allograft at first stage, dermal regeneration matrix (DRM) at second stage, and split thickness skin graft (STSG) for final reconstruction. Fewer cases received a 2-staged approach with DRM and STSG (n=10). No 3-staged cases required repeat STSG, while 40% of 2-staged cases required repeat STSG. Repeat STSG in acute management was significantly associated with patients who received the 2-staged (p<0.01). There was no significant difference in mean baseline DASH scores(p=0.8033) for patients that received cadaveric allograft during acute management (46.5±22.3%) when compared to those who did not (48.7±22.5%). After completing OT, the DASH scores remained comparable (p=0.702) for 3-stage (30.17±20.3%) and 2-stage (26.2±23.4%) management. Conclusion These data suggest a 3-stage approach may conserve autologous STSG, with fewer instances of repeat grafting. This approach may be especially useful when autologous skin is limited. Patients who received a 3-staged approach had comparable mean DASH scores when compared to patients who received a 2-staged approach, suggesting that a 3-staged approach does not diminish the functional benefits of DRM previously demonstrated in the literature.

Purpose: There is limited data available on the remodeling potential of significantly displaced hand fractures of the periarticular phalanx in the pediatric population. Opportunities for closed intervention are limited by rapid healing and, at times, late presentation (1, 2). Open intervention on late-presenting pediatric hand fractures is often of questionable benefit, with its attendant risks including stiffness and nonunion (3). Here we seek to present our experience with non-operative management of significantly displaced pediatric hand fractures over the past 9 years.

Methods and Materials: A retrospective chart review was performed from 2014–2023 to identify patients with significantly displaced phalanx head/neck fractures that did not undergo reduction or formal operative intervention. An absence of tap tenderness (indicating impending/established malunion), as well as an absence of rotational deformity, led to a decision to pursue conservative management. Patients were followed clinically with management including brief immobilization followed by range-of-motion exercises under the supervision of a hand therapist when possible. Statistical analysis was performed using 2-tailed t-tests with Excel, with P value < 0.05.

Results: We identified 17 patients with a total of 18 periarticular phalangeal malunions. Average time from injury to presentation was 35 days (range, 2–271 days) with average follow-up of 87 days (minimum, 25 days). Initial and final sagittal plane angular deformities averaged 35.1° and 19.4° respectively (P < 0.05). In the coronal plane, angular deformities corrected from an average of 13.9° to 9.3° and found to be statistically significant (P < 0.05). Corrected fracture translation percent in the sagittal plane corrected and remodeled from 46.4° at presentation to 31.5° at follow-up (P < 0.05). No patients demonstrated clinical findings warranting operative intervention. No patients experienced a loss of range of motion and no clinical rotational deformities were worsened with non-operative management.

Conclusion: In general, careful consideration should be taken when deciding if a patient may benefit from operative intervention. Radiographic follow-up was short for many patients, and we suspect longer follow-up imaging would demonstrate greater correction in all radiographic measurements. Our results from this retrospective review suggest that non-operative management of significantly displaced periarticular head/neck phalangeal fractures in the pediatric population can result in acceptable remodeling with satisfactory clinical outcomes.

References: 1. Cornwall R, Ricchetti ET. Pediatric Phalanx Fractures: Unique Challenges and Pitfalls. Clinical Orthopaedics and Related Research. 2006;445:146-156. doi:10.1097/01.blo.0000205890.88952.97 2. Cornwall R, Waters PM. Remodeling of phalangeal neck fracture malunions in children: case report. The Journal of Hand Surgery. 2004;29(3):458-461. doi:10.1016/j.jhsa.2004.01.008 3. Puckett BN, Gaston RG, Peljovich AE, Lourie GM, Floyd WE. Remodeling Potential of Phalangeal Distal Condylar Malunions in Children. The Journal of Hand Surgery. 2012;37(1):34-41. doi:10.1016/j.jhsa.2011.09.017

Introduction: Following upper extremity amputations, initiating prosthetic fitting within 30 days of the procedure is critical for patients. This period is known as the "Golden Window". Prosthetic acquisition in this window is associated with higher rates of successful rehabilitation and return to work. Delays can negatively impact the quality of life and long-term productivity of amputees and increase risk of comorbidities and healthcare costs. Unfortunately, more than 50% of patients fail to obtain prosthetics within this optimal timeframe. Increasing costs of prosthetic devices and complexities in insurance coverage have made achieving this target more challenging. The primary objective of this study is to quantify the time lag between amputation and prosthetic acquisition at our single institution to evaluate the feasibility of the Golden Window in current post-amputation rehabilitation. Secondary objectives include exploring the relationship between prosthetic acquisition and indication for amputation, as well as patient- and system-related factors to identify any potential barriers to access that could be addressed.

Methods: We conducted a retrospective analysis using our institution's 2010-2022 DataDirect Database to identify upper extremity amputees based on Current Procedural Terminology (CPT) codes. Patients under 18 years old, those with prior or concurrent major extremity amputations, and those who died within one year post-amputation were excluded. Chart reviews identified the time to prosthetic acquisition, including provisional or preparatory prosthetics. We performed descriptive statistics and multiple logistic regression.

Results: There were 95 patients included. Mean age was 50 years, and the mean Elixhauser score was 3.1. Most patients were male (78%) and white (84%). The indications for amputation included trauma (46%), oncologic (31%), and vascular (12%) cases. Plastic (PLA) and Orthopedic (ORTH) surgeons performed 36% and 59% of the amputations, respectively. Among the cohort, 57% of patients received prosthetics. Only 7% of those patients received prosthetics within 30 days of amputation, whereas 76% and 91% received prosthetics within 6 months and 1 year, respectively. Prosthetics were obtained by 59% of PLA patients and 57% of ORTH patients. Multiple logistic regression did not show significant associations with prosthetic acquisition for age, sex, race, Elixhauser score, indication, and surgeon subspecialty (Table 1).

Conclusions: This study emphasizes the challenge of achieving prosthetic acquisition within the Golden Window after upper extremity amputations. Patient demographics and surgeon subspecialties did not significantly impact prosthetic acquisition. Further research is needed to explore potential barriers and develop strategies to optimize the timing of prosthetic fitting. This may involve the establishment of a multi-disciplinary team employing a more aggressive and streamlined approach to initial prosthetic fitting. Surgeons at our institution should take our study's findings and the ramifications into account when counseling patients on the risks and benefits of amputation and advocate for addressing the delays in prosthetic acquisition encountered by their patients. We encourage surgeons and physical medicine and rehabilitation physicians at other institutions to perform similar evaluations to identify any barriers to prosthetic acquisition that should be addressed.

Purpose: Acute limb ischemia (ALI) is a vascular emergency requiring prompt diagnosis and immediate surgical revascularization to salvage the affected limb. Treating upper extremity ALI requires a comprehensive exploration of the contributing factors, the timeline of tissue response, and the role of immediate clinical intervention. The objective of this study is to investigate the incidence, clinical presentation, and outcomes of upper extremity ALI, and examine their associations with various patient risk factors. Additionally, the study aims to identify potential predictors of poor outcomes in these patients.

Methods: A retrospective review was conducted on patients who underwent upper extremity revascularization for acute limb ischemia within the Cleveland Clinic Healthcare System between 2003 and 2023. Only patients with an ischemia time of less than 14 days were included. Demographic information, risk factors for hypercoagulability (including pre-existing medical conditions, medications, and substance use history), duration of ischemia, symptoms prior to revascularization, etiology of ischemia, length of hospitalization, and postoperative complications were analyzed.

Results: Three hundred sixty-six patients underwent revascularization for ALI during the study period. The average age of the patients was 65.02±16.95 years, and 69.7% were female. The most common etiologies of ALI included embolism from atrial fibrillation (21.5%) and iatrogenic injury (29.3%). Most patients had multiple sites of occlusion, most commonly with involvement of the brachial artery (89%). The median ischemia time for all patients was 12 hours (IQR=29.25). Presence of pain (p=0.024) and paresthesia (p=0.037) at the initial presentation were significantly associated with increased duration of ischemia. A total of 80 patients (21.9%) experienced complications, which included re-occlusion requiring re-thrombectomy (n=27), compartment syndrome requiring fasciotomy (n=19), wound necrosis (n=6) and/or persistent ischemia (n=2) requiring amputation, hematoma (n=21), dehiscence (n=3), and infection (n=2). Ischemia duration did not have a significant association with postoperative complications (p=0.13) or correlation with length of hospitalization (r=-0.06, p=0.25). Eleven patients (3%) received a prophylactic fasciotomy to prevent the development of compartment syndrome. The median ischemia duration in these patients was 14.5 hours (IQR=53.75), which was not significantly different to the patients without prophylactic fasciotomy (p=0.25), but symptoms of pallor (p=0.001) and cyanosis (p=0.0007) were more likely to be present in the patients who received prophylactic fasciotomy. Prophylactic fasciotomy was associated with increased complications (p=0.0012) with no significant change in length of hospitalization (p=0.83) compared to the patients without prophylactic fasciotomy.

Conclusion: Revascularization for upper extremity ALI is generally associated with a high rate of postoperative complications. Although increased ischemia duration may present with more pronounced symptoms, it is not a predictor of postoperative outcomes such as complications and length of hospitalization. Additionally, with no clear clinical indication for prophylactic fasciotomy following upper extremity revascularization, the increased risk of complications associated with this procedure may outweigh its intended benefit of preventing compartment syndrome.

Introduction:

Carpal tunnel syndrome (CTS) is a common condition characterized by compressive median mononeuropathy at the wrist. Despite its high prevalence, there is a notable discrepancy between the number of individuals affected and those receiving treatment, potentially due to underdiagnosis, undertreatment, and various barriers to effective care. Traditional treatment options include open or endoscopic surgery, with the latter gaining popularity due to its minimally invasive nature, quicker recovery, and reduced postoperative pain. The WALANT method, utilizing local anesthesia with lidocaine and epinephrine, enables surgery without a tourniquet, minimizing discomfort and allowing the procedure to be performed in an awake patient, thus enhancing safety and convenience.

The study introduces a novel approach by integrating three techniques: endoscopic carpal tunnel release (ECTR), WALANT technique, and conducting the procedure in an office setting for cost-effectiveness and convenience. This retrospective chart review aims to evaluate the outcomes and patient experiences of this innovative method, purported to enhance recovery speed, safety, and overall patient satisfaction.

Methods:

The study involved patients who underwent ECTR by a single surgeon from November 2021 to November 2023, assessing preoperative symptoms, and postoperative outcomes through questionnaires focusing on pain levels, satisfaction, and symptom improvement.

Results:

A total of 315 patients underwent the procedure, with 222 surgeries analyzed after excluding those with conjoined procedures or incomplete follow-ups. The procedure demonstrated a significant reduction in symptom severity, with a notable decrease in preoperative symptoms from a median number of 5 to 0 postoperatively. Patient satisfaction was high, with 79.3% reporting their experience exceeded expectations, and an additional 18.5% reported it met their expectations. 82.9% reported they would highly recommend the procedure to others. The return to regular activities, averaged 8.65 days, with a median of 7 days. No postoperative infections were observed. Complete dissatisfaction was observed in 5 patients (2% of the total), who reported an experience worse than expected. Importantly, no patients demonstrated intolerance to Wide Awake Local Anesthesia with No Tourniquet (WALANT) surgery. During the surgical procedure, the mean pain score was less than one (mean of 0,63) on a 0-10 Numerical Rating Scale (NRS).

Discussion:

The in-office WALANT ECTR represents a transformative approach in the treatment of CTS, offering patients a highly effective, minimally invasive, and patient-centered alternative to traditional surgical interventions. The significant improvements in patient outcomes, combined with high levels of satisfaction and quick recovery times, highlight the potential of this technique to revolutionize CTS treatment protocols and patient care standards.

Purpose: The existing diagnostic criteria for septic wrist are non-specific, subjecting patients with non-infectious etiologies to surgical morbidity. This study aimed to create a septic wrist AI prediction model and develop a score-based risk assessment tool.

Methods: An IRB-approved retrospective review was conducted on patients with a presumed septic wrist diagnosis (2003 – 2022). Patients were excluded if neither arthrocentesis nor open drainage was performed. Kruskal Wallis algorithm was employed to identify potential predictors of septic wrist based on factors including comorbidities (autoimmune diseases, immunosuppression, prior crystalline arthropathy, prior septic arthritis, IVDU, smoking), penetrating trauma, fever, multi-joint involvement, inflammatory markers (ESR/CRP/WBC), serum uric acid, blood cultures, imaging, and synovial fluid analysis. Subsequently, Naïve Bayes classifier was utilized to populate a prediction model based on the identified predictors. Concurrently, an independent score-based risk assessment tool was developed using traditional multivariate analyses. In this tool, each predictor received a standardized risk score of 1, and the optimal cutoff for classifying patients with septic wrist was established. Performance of both methods were evaluated with ROC curve.

Results: 205 (70 females and 135 males) patients were included with an average age of 60 ± 16 years. The median length of hospitalization was 6 [8] days and follow-up duration 1 [3] months. 95 (46.3%) patients had septic wrist confirmed with Gram stain/culture, 79 (38.5%) patients received alternative diagnoses (crystalline arthropathy, tenosynovitis, cellulitis, abscesses, ligamentum injury, and arthritic flare), and 31 (15.1%) patients had undetermined diagnoses. Concomitant septic wrist and crystalline arthropathy was identified in 11 patients (5%). The optimized Naïve Bayes prediction model included 7 predictors (no synovial crystals, positive blood culture, multi-joint involvement, age, history of septic arthritis, IVDU, and penetrating trauma) with a sensitivity of 89.5%, specificity of 80%, and an AUC of 0.89. The score-based risk tool comprised 4 predictors (negative synovial crystals, positive blood culture, negative history of crystalline arthropathy, and multi-joint involvement), resulting in a risk score ranging from 0 to 4. Classifying patients with septic wrist at a score of ≥2 yielded an optimized sensitivity of 64%, specificity of 84%, and AUC of 0.78.

Conclusions: Both the AI prediction model and the traditional statistical score-based risk assessment tool can offer valuable support for clinical decision-making in cases of suspected septic wrist. The most significant predictors for septic wrist include multi-joint involvement, absence of synovial crystals, and positive blood culture.

PURPOSE: Replanting severed digits poses technical challenges with varying success rates. Prior studies note a decline in national digit replantation occurrences, but no post-2010 follow-up exists.[1] Limited research explores long-term complications or necessary revision surgeries post-successful replantation. We aim to delineate digit replantation incidence, patient outcomes, and pinpoint risk factors necessitating further revision procedures.

METHODS: Digital replantation data were extracted from TriNetX, a global health research database, using CPT and ICD-10 codes. Information on patient demographics, comorbidities, injury mechanisms, and subsequent surgeries was collected. Patients were identified by digit replantation (CPT-20816, CPT-20822, CPT-20824, CPT-20827), with or without any subsequent digit amputation (CPT-26952, CPT-26910, CPT-26951). Injury mechanisms included crush (ICD10-S67), powered hand tools or machinery (ICD10-W29), being struck by objects or sports equipment (ICD10-W20, W21, W22, W23), and knife injuries (ICD10-W26).

Descriptive statistics were compiled on subsequent revision surgeries, such as skin or soft tissue debridement, neurolysis, hardware removal, bone or joint repair, and tendon advancements or repair. Revision amputation (RA) incidence, replantation survival rates, and risk factors were analyzed using risk percentages, odds ratios with 95% confidence intervals (CI), and Chi-Squared tests with a significance level of 0.05.

RESULTS: Between 1/1/1990 and 12/23/2023, there were 1,221 patients who underwent digit replantation, with 1,040 (84%) identifying as male, and 782 (64%) as Caucasian. Replant cases per year hit a low of 11 in 2007, rising to a peak of 101 in 2019. More replants were attempted on thumbs and metacarpophalangeal amputations, though not statistically significant. Subsequently, 456 (37%) underwent RA. The incidence of RAs was 28 (6.2%) post-operative day 1 (POD1), 37 (8.1%) on POD3, 25 (5.5%) on POD7, and 17 (3.8%) on POD14. Of the 456 patients who required RA, 191 (42%) occurred by POD7 and 365 (99%) occurred by POD365. The 7, 30, and 90-day survival rates for replanted digits were 84%, 68%, and 65%, respectively.

Injury mechanism was not significantly associated with RA risk. Within one year of the initial replant, 50 patients underwent RA underwent debridement prior to their eventual amputation (11%), which is more than successful replant patients (49[6.4%]; OR=1.8; CI=1.19-2.72). Skin or soft tissue debridement, hardware removal, and tendon repairs did not have statistical differences between the two groups.

CONCLUSION: Since the national report on digital implants using data from 2010, the incidence of digital replants has steadily increased compared to previous studies.[1] Replanted digits that survive beyond 14 days typically remain viable, with the majority of failures occurring within the first year post-surgery. The absence of a significant association between injury mechanisms and replant success may be due to improper or incomplete use of ICD codes. Understanding the risk factors affecting short- and long-term success, along with the need for revision surgeries, is crucial for surgical planning and patient counseling post-traumatic amputation. Since a significant limitation of our research lies in our inability to associate a specific replanted digit with its corresponding amputation, future studies could explore the development of a database to access more granular data.

[1] Reavey PL, Stranix JT, Muresan H, Soares M, Thanik V. Disappearing Digits: Analysis of National Trends in Amputation and Replantation in the United States. Plast Reconstr Surg. 2018 Jun;141(6):857e-867e. doi: 10.1097/PRS.0000000000004368. PMID: 29794703.

Purpose: Carpal Tunnel Syndrome (CTS) is the most diagnosed peripheral compressive neuropathy. The diagnosis of CTS is typically clinical, however shear wave elastography (SWE) may be an interesting non-invasive tool to test properties of the median nerve (MN). Currently, shear wave elastography (SWE) is the only clinically available method capable of quantitative assessment of soft tissue stiffness. SWE has been used to non-invasively assess the stiffness of the MN and can be used for diagnosing carpal tunnel syndrome (CTS). Research is limited in this area and there has been no previous study attempting to correlate treatment outcomes with pretreatment diagnostic results. Our study underscores the necessity for a deeper comprehension of the pathophysiology underlying CTS and the need for a more critical evaluation of the traditional treatment of CTS using corticosteroid, as these injections may not affect median nerve stiffness or swelling like we once thought. The purpose of this study is to correlate SWE measurements with patient-reported outcomes and analyze changes in SWE in response to corticosteroid injection.

Methods: Ten patients (18 hands) were included based on CTS-6 score and proximal cross-sectional area (CSA) of the MN > 10mm2. Patients completed a Boston Carpal Tunnel Questionnaire and underwent evaluation with ultrasound and SWE protocol. After 6 weeks, patients were re-evaluated with the same metrics, treatment failure was recorded as need for carpal tunnel release (CTR).

Results: Five patients (six hands) went on to CTR. Patients needing CTR had inferior post injection FSS (p=0.03) and SSS (<0.01). Those not undergoing surgery had smaller cross sectional diameters of the median nerve proximal to the carpal tunnel post treatment (p=0.03). There was no significant difference in velocity or pressure in the MN on SWE or CSA on ultrasound before or after injection. Elastography was not associated with the need for CTR.

Conclusions: While some patients undergoing injection for CTS did have clinical improvement, we did not detect changes in the MN with regard to SWE or CSA. Our findings suggest corticosteroid injections may not affect MN swelling or elastography. This study furthers our understanding of one of the most common hand pathologies, potentially prompting healthcare practitioners to reevaluate their approach to CTS management due to the highlighted limitations in current knowledge and practices. The absence of changes in MN characteristics with corticosteroid injections suggests a need for further research into the efficacy of this traditional treatment. Additionally, the study questions the clinical utility in use of SWE in predicting symptom relief post- injection or the need for carpal tunnel release. These findings may drive clinicians to explore alternative diagnostic tools to improve our understanding of prognostic indicators, and, therefore, patient care outcomes.

INTRODUCTION: By leveraging natural language processing and machine learning capabilities, artificial intelligence models like OpenAI's ChatGPT (1) show potential providing medical knowledge, such as answering questions regarding common hand surgeries (2). A recent update has allowed users to directly upload images into ChatGPT-4. However, there is little research on whether ChatGPT can accurately interpret medical images such as radiographs. Accurate interpretation of hand imaging by ChatGPT can support clinical decision-making, especially for hand surgeons. This study aims to evaluate ChatGPT-4's accuracy in identifying bones within hand radiograph images when presented with visual cues.

METHODS: A single posterior-anterior (PA) radiograph of an anatomically normal hand was utilized to create 30 figures, each featuring annotations of different bones using red circles or arrows. Fifteen bones of interest were annotated: proximal phalanx of the fifth digit, middle phalanx of the second digit, distal phalanx of the first digit, second metacarpal, first metacarpal, all eight carpal bones, radius, and ulna. Sixty images were presented individually to ChatGPT with a prompt to identify the annotated bone. A scoring system was employed to assess correctness; full accuracy was scored as 10 points. Responses featuring multiple bones were penalized two points. Descriptive statistics were used to analyze results, and a paired, two-tailed t-test was conducted to compare accuracy between images annotated with circles and arrows.

RESULTS: ChatGPT provided a completely correct, partially correct, and completely incorrect identification for five (8.3%), 49 (81.7%), and six (10%) bones, respectively. The five images in which ChatGPT provided a completely correct identification all used circles. ChatGPT's average accuracy score was 4.1±3.0. ChatGPT demonstrated slightly higher accuracy for circle-annotated images than arrow-annotated ones (4.6±3.0 vs. 3.5±2.9), but this was not statistically significant (p-value 0.11). ChatGPT was asked only to identify the one circled or indicated bone; however, ChatGPT listed more than one bone for 18 (30%) of responses. The average response identified 1.3±0.6 bones (range 1-4). Although only four images had an annotated scaphoid, ChatGPT reported this being the annotated bone in 34 (56.7%) of images. However, ChatGPT failed to identify the triquetrum, pisiform, trapezoid, capitate, and hamate in any of its responses. The fifth metacarpal was not annotated in any images; however, ChatGPT identified this bone in 15 (25.0%) of responses.

CONCLUSION: ChatGPT-4 shows potential but notable limitations in bone identification within hand radiographs. While partially correct, it struggles with full accuracy and frequently provides multiple bone responses. Additionally, misidentification of the scaphoid and fifth metacarpal suggests that despite its ability to process visual cues, ChatGPT's responses are ultimately driven by statistical patterns within training data rather than genuine image interpretation. While ChatGPT has potential in clinical practice, significant development and refinement are required before reliable image interpretation.

REFERENCES: 1. OpenAI. ChatGPT. https://chat.openai.com/chat 2. Crook BS, Park CN, Hurley ET, Richard MJ, Pidgeon TS. Evaluation of Online Artificial Intelligence-Generated Information on Common Hand Procedures. The Journal of Hand Surgery. 2023/11/01/ 2023;48(11):1122-1127. doi:https://doi.org/10.1016/j.jhsa.2023.08.003

Hypothesis The ulnar nerve provides critical motor function such as wrist flexion, opposition, and intrinsic hand function. Given this role, extensive efforts are made to restore hand function after injuy through repair, grafting, or nerve transfer. Proximally, the ulnar nerve may also serve as a fascicular donor to restore elbow flexion and extension. However, despite use of nerve transfers and microsurgical techniques to optimize nerve repair and grafting, outcomes remain variable. We hypothesized this variability results from sub-optimal pairing of donor and recipient motor axons due to a scarcity of ideally situated axons. We thus sought to review the literature to assess motor and sensory axon differences throughout the ulnar nerve to further inform and optimize our care and use of the ulnar nerve.

Methods We systematically reviewed MEDLINE and PUBMED databases using the search term "(ulnar nerve) AND ((fascicle) OR (axon))." Inclusion criteria was anatomic studies of human adult cadavers, with quantitative data on axons or fascicles from non-pathologic specimens published in a peer-reviewed journal. Weighted means and standard deviations of total, motor, and sensory axon counts at different levels of the ulnar nerve, ranging from the axilla to distal branches at the wrist, were reported.

Results After reviewing 472 articles, 13 were analyzed. At the level of the axilla, studies report 28,097 [SD 2920; range 14234 – 40379] total axons, including 3,583 (12.8%) [3054; 2670 – 4171] motor axons. At the mid-forearm level, 20,259 [could not calculate; 12267 - 30914] axons were reported, and 1,199 (5.92%)[241; 1,199 – 1,199] motor axons. The ulnar nerve is reported to increase to 26,897 [SD 4966; 26,897 – 26,897] axons proximal to the pronator quadratus, where 2,326 (8.65%)[SD 1019; 1216 - 2913] motor axons can be found. At the level of the wrist, the ulnar nerve has 26,610 [3133; 26,610 - 26,610] axons of which 1,230 (4.62%) [SD 256.4; 1203 – 1427] are motor axons. Finally, distal to the wrist, 2,080 [SD 704; 1368 – 2634] motor axons can be found, with no studies reporting total axon numbers at this level.

Ultimately, in addition to a large range in axon counts, a lack of reporting clarity was discovered. Some articles reported total axon counts in the MBUN, others reported motor axon counts in the ulnar nerve at a level, and the rest some other permutation of these options. Few articles reported both total and motor axon counts at a level or within a fascicle.

Conclusion The current literature on axon counts in the ulnar nerve and its fascicles is highly variable. However, it appears that motor axons contribute to only a small portion of the ulnar nerve, composing anywhere from 4.62% to 12.8% of the total number of axons in the nerve. Interestingly, though one would expect that the percent contribution of motor axons would increase moving distally, the literature indicates fluctuations up and down from the axilla to the hand. Ultimately, these findings reflect the continued need for further detailed evaluation of the microarchitecture to improve reinnervation with the ulnar nerve.

Purpose: This study investigates the outcomes of end-to-side (ETS) nerve transfers versus end-to-end (ETE) nerve transfers for surgical treatment of glenohumeral dysplasia (GHD) due to brachial plexus birth injury (BPBI).

Methods: BPBI infants presenting with persistent weakness of the upper trunk and functional limitations of the shoulder with concomitant GHD confirmed by ultrasonography who either underwent ETS or ETE nerve transfer of the spinal accessory nerve (SAN) to the suprascapular nerve (SSN) between January 2022 to December 2023, were included in the study. Calculations of the alpha angle on serial ultrasound images and AMS scores for shoulder abduction (SA), forward flexion (FF), and external rotation (ER), prior to and following either approach were used as outcome measurements. Statistical analysis of the outcomes of each approach was conducted using a Wilcoxon Signed Rank Test. Further analysis was conducted using a Mann-Whitney U Test, Fisher's Exact Test, and t-tests when applicable. The level of significance was set at p < 0.05.

Results: Seven patients underwent ETS nerve transfer and five patients underwent ETE nerve transfer within the study period. Following an ETS approach, all seven participants demonstrated significant improvement of alpha angle measurements on ultrasound findings (p < 0.05), full recovery of ER (AMS of 7) (p < 0.05), and functional recovery of SA and FF shoulder function (AMS of 6 or 7) (p < 0.05). Additionally, following an ETE approach, all five participants demonstrated significant improvement of alpha angle measurements on ultrasound findings (p < 0.05), functional recovery of SA and FF (p < 0.05), but with no significant difference in AMS ER scores (p = 0.066). When comparing the changes of outcome measurements prior to and following the two different treatment modalities, there was no significant difference for either outcome measurement. Overall, when comparing the two treatment modalities in their ability to correct GHD, a Fisher's Exact Test did not find any significant difference (p = 0.15). Importantly, two out of the five patients who underwent ETE for GHD required further operations (external rotation tendon transfers) to correct shoulder function, while none of those who underwent ETS required secondary procedures.

Conclusions:
In our study, both the ETS and ETE cohorts demonstrated success in resolving GHD (measured on ultrasonography). Both cohorts also demonstrated significant improvement in functional AMS shoulder scores, with the exception of the ETE cohort in AMS ER. Comparison of the ETS and ETE techniques demonstrated no significant differences in changes of AMS scores and found no overall difference between either modality to correct for GHD following BPBI.