Neonatal brachial plexus palsy with neurotmesis of C5 and avulsion of C6: supraclavicular reconstruction strategies and outcome

Brachial Plexus Birth Injuries

Brachial plexus birth injuries (BPBIs) are typically traction type injuries to the newborn that occur during the delivery process. Although the incidence of these injuries has overall decreased from 1.5 to around 0.9 per 1000 live births in the United States over the past 2 decades, these injuries remain common, with incidence holding fairly steady from 2008 to 2014. Shoulder dystocia is the strongest identified risk factor, imparting a 100-fold greater risk. The newborn's shoulder is caught behind the mother's pubic bone, and traction performed on the child during delivery results in injury to the brachial plexus. Other risk factors associated with BPBI include macrosomia (birthweight > 4.5 kg), heavy for gestational age infants, birth hypoxia, gestational diabetes, and forceps or vacuum-assisted delivery. Breech presentation has also been described as a risk factor in the past, but there have been more recent data that challenge this association.

Surgical timing in neonatal brachial plexus palsy: A PRISMA-IPD systematic review

Background

Neonatal brachial plexus palsy (NBPP) is a serious complication of high‐risk deliveries with controversy surrounding timing of corrective nerve surgery. This review systematically examines the existing literature and investigates correlations between age at time of upper trunk brachial plexus microsurgery and surgical outcomes.

Methods

A systematic screening of PubMed, Cochrane, Web of Science, and CINAHL databases using PRISMA‐IPD guidelines was conducted in January 2020 to include full‐text English papers with microsurgery in upper trunk palsy, pediatric patients. Spearman rank correlation analysis and two‐tailed t‐tests were performed using individual patient data to determine the relationship between mean age at time of surgery and outcome as determined by the Mallet, Medical Research Council (MRC), or Active Movement Scale (AMS) subscores.

Results

Two thousand nine hundred thirty six papers were screened to finalize 25 papers containing individual patient data (n = 256) with low to moderate risk of bias, as assessed by the ROBINS‐I assessment tool. Mallet subscore for hand‐to‐mouth and shoulder abduction, AMS subscore for elbow flexion and external rotation, and MRC subscore for elbow flexion were analyzed alongside the respective age of patients at surgery. Spearman rank correlation analysis revealed a significant negative correlation (ρ = −0.30, p < .01, n = 89) between increasing age (5.50 ± 2.09 months) and Mallet subscore for hand‐to‐mouth (3.43 ± 0.83). T‐tests revealed a significant decrease in Mallet hand‐to‐mouth subscores after 6 months (p < .05) and 9 months (p < .05) of age. No significant effects were observed for Mallet shoulder abduction, MRC elbow flexion, or AMS elbow flexion and external rotation.

Conclusion

The cumulative evidence suggests a significant negative correlation between age at microsurgery and Mallet subscores for hand‐to‐mouth. However, a similar correlation with age at surgery was not observed for Mallet shoulder abduction, MRC elbow flexion, AMS external rotation, and AMS elbow flexion subscores.

Surgical Management of Traumatic Brachial Plexus Injuries in the Pediatric Population

OBJECTIVE

The aim of this study was to evaluate the demographics, treatment options, and outcomes of pediatric age traumatic brachial plexus injuries (BPI).

METHODS

Traumatic brachial plexus reconstructions in patients aged 17 years or younger were reviewed. Patients were stratified into pan-plexus and incomplete plexus injuries. Functional outcomes (modified British Medical Council Grade -mBMRC) were reviewed after a minimum of 9 months follow-up.

RESULTS

Seventy-one patients underwent brachial plexus reconstruction at an average age of 13.9 years (Range 2-17 years). Approximately half of patients had a pan-brachial plexus injury (n=33, 46.5%) with 59.2% having at least one preganglionic avulsion injury. Twenty-five patients with pan-brachial plexus injuries had follow-up greater than 9 months, of which 12 (48%), 24 (96%), and 17 (68%) had reconstruction surgery for shoulder, elbow, and grasp function, respectively. At last follow-up, 50%, 83%, and 29% of these patients had grade 3 or greater mBMRC in shoulder abduction, elbow flexion, and grasp, respectively. Of the 31 patients with incomplete BPI, 28 (90%) underwent reconstruction for shoulder function, and 13 (42%) had surgery for elbow flexion. At last follow=up, 71% and 100% of patients had grade 3 mBMRC testing in shoulder abduction and elbow flexion.

CONCLUSIONS

Pediatric traumatic BPI are often high energy injuries resulting in nerve root avulsions. Most patients were able to regain anti-gravity elbow flexion or stronger after brachial plexus reconstruction, and over half had similar improvement in shoulder function. Treatment should be directed with goals of elbow flexion, shoulder stability/external rotation, and rudimentary grasp.

Nerve Graft and Nerve Transfer for Improving Elbow Flexion in Children with Obstetric Palsy. A Systematic Review

Obstetric brachial plexus palsy is a rather common injury in newborns, caused by traction to the brachial plexus during labor. In this context, with the present systematic review, we aimed to explore the use of nerve graft and nerve transfer as procedures to improve elbow flexion in children with obstetric palsy. For the present review, we followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We searched the MEDLINE, EMBASE, LILACS, The Cochrane Central Register of Controlled Trials, Web of Science, Wholis and SCOPUS databases. Predetermined criteria defined the following requirements for inclusion of a study: Clinical trials, quasi-experiments, and cohort studies that performed nerve graft and nerve transfer in children (≤ 3 years old) with diagnosis of obstetric palsy. The risk of bias in nonrandomized studies of interventions assessment tool was used for nonrandomized studies. Out of seven studies that used both procedures, three of them compared the procedures of nerve graft with nerve transfer, and the other four combined them as a reconstructive method for children with obstetric palsy. According to the Medical Research Council grading system, both methods improved equally elbow flexion in the children. Overall, our results showed that both techniques of nerve graft and nerve transfer are equally good options for nerve reconstruction in cases of obstetric palsy. More studies approaching nerve reconstruction techniques in obstetric palsy should be made, preferably randomized clinical trials, to validate the results of the present systematic review.

Surgical Reconstruction of Isolated Upper Trunk Brachial Plexus Birth Injuries in the Presence of an Avulsed C5 or C6 Nerve Root

BACKGROUND

Avulsion of either the C5 or C6 root with intact middle and lower trunks in brachial plexus birth injury is rare. In these cases, only 1 proximal root is available for intraplexal reconstruction. The purpose of the present study was to determine the outcomes of these patients when single-root reconstruction was balanced across the anterior and posterior elements of the upper trunk.

METHODS

We performed a retrospective cohort study of prospectively collected data for patients with brachial plexus birth injury who underwent primary nerve reconstruction between 1993 and 2014. Patients were included who had isolated upper-trunk injuries with intact middle and lower trunks. The study group had avulsion of either the C5 or C6 root. The control group had neuroma-in-continuity or ruptures of the upper trunk. Outcomes were assessed with use of the Active Movement Scale and the Brachial Plexus Outcome Measure. The Wilcoxon signed-rank test was utilized to evaluate changes across treatment.

RESULTS

Ten patients with brachial plexus birth injury were included in the avulsion cohort. Surgical reconstruction entailed neuroma resection and nerve grafting from the single available root balanced across all distal targets with or without spinal accessory-to-suprascapular nerve transfer. Significant improvements were observed across treatment for both the avulsion and control groups in terms of shoulder abduction, shoulder flexion, external rotation, elbow flexion, and supination. At a mean follow-up of 54.5 ± 8.8 months, patients in the avulsion group achieved Active Movement Scale scores of 6.8 ± 0.4 for elbow flexion and 6.5 ± 0.9 for shoulder flexion and abduction, with lesser recovery observed in external rotation (3.3 ± 2.8). All patients available for Brachial Plexus Outcome Measure assessments demonstrated functional movement.

CONCLUSIONS

In the setting of avulsion of 1 upper-trunk root, nerve reconstruction by grafting of the upper trunk from the other upper-trunk root provides improved movement, high Active Movement Scale scores, and satisfactory function according to the Brachial Plexus Outcome Measure. These data provide support for a strategy that ensures the entire upper trunk is adequately reconstructed in the setting of upper-trunk lesions.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Brachial Plexus Birth Injuries: A Critical Analysis Review

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The incidence of brachial plexus birth injury (BPBI) in the United States is declining and now occurs in <1 per 1,000 births.

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The gold standard for predicting the need for early intervention remains serial examination.

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Early treatment of BPBI with reconstructive surgery requires the ability to perform both interposition nerve grafting and nerve transfers.

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Given the heterogeneity of lesions, the evidence is largely limited to retrospective comparative studies and case series.

Surgical Reconstruction of Isolated Upper Trunk Brachial Plexus Birth Injuries in the Presence of an Avulsed C5 or C6 Nerve Root

BACKGROUND

Avulsion of either the C5 or C6 root with intact middle and lower trunks in brachial plexus birth injury is rare. In these cases, only 1 proximal root is available for intraplexal reconstruction. The purpose of the present study was to determine the outcomes of these patients when single-root reconstruction was balanced across the anterior and posterior elements of the upper trunk.

METHODS

We performed a retrospective cohort study of prospectively collected data for patients with brachial plexus birth injury who underwent primary nerve reconstruction between 1993 and 2014. Patients were included who had isolated upper-trunk injuries with intact middle and lower trunks. The study group had avulsion of either the C5 or C6 root. The control group had neuroma-in-continuity or ruptures of the upper trunk. Outcomes were assessed with use of the Active Movement Scale and the Brachial Plexus Outcome Measure. The Wilcoxon signed-rank test was utilized to evaluate changes across treatment.

RESULTS

Ten patients with brachial plexus birth injury were included in the avulsion cohort. Surgical reconstruction entailed neuroma resection and nerve grafting from the single available root balanced across all distal targets with or without spinal accessory-to-suprascapular nerve transfer. Significant improvements were observed across treatment for both the avulsion and control groups in terms of shoulder abduction, shoulder flexion, external rotation, elbow flexion, and supination. At a mean follow-up of 54.5 ± 8.8 months, patients in the avulsion group achieved Active Movement Scale scores of 6.8 ± 0.4 for elbow flexion and 6.5 ± 0.9 for shoulder flexion and abduction, with lesser recovery observed in external rotation (3.3 ± 2.8). All patients available for Brachial Plexus Outcome Measure assessments demonstrated functional movement.

CONCLUSIONS

In the setting of avulsion of 1 upper-trunk root, nerve reconstruction by grafting of the upper trunk from the other upper-trunk root provides improved movement, high Active Movement Scale scores, and satisfactory function according to the Brachial Plexus Outcome Measure. These data provide support for a strategy that ensures the entire upper trunk is adequately reconstructed in the setting of upper-trunk lesions.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

C5-8 neonatal brachial plexus palsy. Operative findings, reconstructive strategy and outcome

From 1998 to 2014, we performed primary brachial plexus repair in 260 children with neonatal brachial plexus palsy. Thirty-three presented with a C5-8 palsy and 24 were reviewed for this study. The surgical strategy was to focus on repairing the upper trunk. Secondary surgical procedures were performed in 21 patients, mainly for shoulder external rotation deficit or weak wrist extension. After a mean follow-up of 9.7 years (range 3 to 19), the median Mallet score for the shoulder was 9.5 and the mean Raimondi score for the hand was 3.3. Median active movement scale was 5, 7 and 5.5 for the deltoid, biceps and triceps, respectively. We conclude that primary C5-8 brachial plexus reconstruction provides restoration of elbow flexion and most patients have a sensitive and functional hand. We also found that secondary surgery to improve shoulder and wrist function is often necessary, which should initially be explained to the family.Level of evidence: IV.

Reconstruction of the Suprascapular Nerve in Brachial Plexus Birth Injury: A Comparison of Nerve Grafting and Nerve Transfers

BACKGROUND

Shoulder external rotation recovery in brachial plexus birth injury is often limited. Nerve grafting to the suprascapular nerve and transfer of the spinal accessory nerve to the suprascapular nerve are commonly performed to restore shoulder external rotation, but the optimal surgical technique has not been clearly demonstrated. We investigated whether there was a difference between nerve grafting and nerve transfer in terms of shoulder external rotation recovery or secondary shoulder procedures.

METHODS

This is a multicenter, retrospective cohort study of 145 infants with brachial plexus birth injury who underwent reconstruction with nerve grafting to the suprascapular nerve (n = 59) or spinal accessory nerve to suprascapular nerve transfer (n = 86) with a minimum follow-up of 18 months (median, 25.7 months [interquartile range, 22.0, 31.2 months]). The primary outcome was the Active Movement Scale (AMS) score for shoulder external rotation at 18 to 36 months. The secondary outcome was secondary shoulder surgery. Two-sample Wilcoxon and t tests were used to analyze continuous variables, and the Fisher exact test was used to analyze categorical variables. The Kaplan-Meier method was used to estimate the cumulative risk of subsequent shoulder procedures, and the proportional hazards model was used to estimate hazard ratios (HRs).

RESULTS

The grafting and transfer groups were similar in Narakas type, preoperative AMS scores, and shoulder subluxation. The mean postoperative shoulder external rotation AMS scores were 2.70 in the grafting group and 3.21 in the transfer group, with no difference in shoulder external rotation recovery between the groups (difference, 0.51 [95% confidence interval (CI), -0.31 to 1.33]). A greater proportion of the transfer group (24%) achieved an AMS score of >5 for shoulder external rotation compared with the grafting group (5%) (odds ratio, 5.9 [95% CI, 1.3 to 27.4]). Forty percent of the transfer group underwent a secondary shoulder surgical procedure compared with 53% of the grafting group; this was a significantly lower subsequent surgery rate (HR, 0.58 [95% CI, 0.35 to 0.95]).

CONCLUSIONS

Shoulder external rotation recovery in brachial plexus birth injury remains disappointing regardless of surgical technique, with a mean postoperative AMS score of 3, 17% of infants achieving an AMS score of >5, and a high frequency of secondary shoulder procedures in this study. Spinal accessory nerve to suprascapular nerve transfers were associated with a higher proportion of infants achieving functional shoulder external rotation (AMS score of >5) and fewer secondary shoulder procedures.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Outcomes of Spinal Accessory-to-Suprascapular Nerve Transfers for Brachial Plexus Birth Injury

PURPOSE

The results of a spinal accessory nerve-to-suprascapular (SAN-SSN) nerve transfer for brachial plexus birth injuries (BPBIs) have thus far been presented only in limited case series. Our study evaluates the recovery of shoulder function of patients who underwent an SAN-SSN for BPBI as an isolated procedure or as part of a multinerve reconstruction (MNR) surgery.

METHODS

We retrospectively reviewed the medical records of patients at a single institution who underwent an SAN-SSN after BPBI. Inclusion criteria were patients with both preoperative and a minimum 12-months postoperative active movement scale (AMS) scores. Patients for whom the primary surgery involved tendon transfers were excluded. The primary outcome measures were AMS scores for shoulder abduction, forward flexion, and external rotation and secondary outcomes included the need for further shoulder surgery to improve function.

RESULTS

Seventy-three patients met the inclusion criteria. Forty-three patients (58.9%) obtained functional shoulder motion (AMS ≥ 6) of at least 1 of 3 planes (abduction/flexion/external rotation) following surgery, with 13 patients (17.8%) achieving full recovery of 1 of these shoulder motions against gravity (AMS = 7). Fifty-six patients (76.7%) did not undergo subsequent tendon transfers or corrective osteotomies to augment shoulder function. The MNR procedures were performed in 46 patients (63%), of whom 45.7% gained a functional recovery. In 27 patients for whom SAN-SSN nerve transfer was conducted in isolation, 81.5% gained functional shoulder motion. However, isolated SAN-SSNs were conducted at a later age than MNR procedures (13.2 vs 4.8 months) and had higher preoperative AMS scores. The anterior and posterior approaches for SAN-SSN were both found to be effective when used for SAN-SSN in BPBI. When the follow-up duration cutoff was set to 3 years, the outcomes were found to be superior.

CONCLUSIONS

In 76.7% of the patients, SAN-SSN was able to recover function that was sufficient to prevent tendon transfers and corrective osteotomies. A cutoff of 3 postoperative years should be used as a benchmark for analyzing the results of this procedure.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Elbow flexion in neonatal brachial plexus palsy: a meta-analysis of graft versus transfer

BACKGROUND

Functional elbow flexion recovery is one of the main goals of neonatal brachial plexus palsy (NBPP) reconstruction. The current neurosurgical treatment options include nerve grafting and nerve transfer.

OBJECTIVE

The present study sought to examine the literature for comparison of functional elbow flexion recovery in NBPP following nerve grafting or nerve transfer. We conducted a systematic literature review and meta-analysis according to PRISMA guidelines. A search was conducted on Pubmed/Medline and Cochrane for eligible studies published until November of 2018. Odd ratios (OR) and 95% confidence intervals (CI) were calculated to compare functional elbow flexion outcomes between nerve graft and nerve transfer. A random effects model meta-analysis was conducted. A Medical Research Council (MRC) score ≥ 3 or Active Movement Scale (AMS) ≥ 5 was considered a functional recovery of elbow flexion.

RESULTS

The present study included 194 patients from 1990 to 2015 across five observational trials. Only pediatric patients with obstetric brachial plexus injury were included. The mean patient age at surgery varied between studies from 5.7 months to 11.9 months and mean follow-up from 12 to 70 months. No complications or cases of donor site morbidity were reported. From the included studies, 118 patients were reported with MRC or AMS scoring usable for odd ratio comparison. Functional recovery occurred with nerve transfer in 95.2% of patients (n = 59/62) and with nerve grafting in 96.4% of patients (n = 54/56). Overall, the outcomes for elbow flexion between the groups appeared similar (OR 1.15, 95% CI 0.19-7.08, I² 2.9%).

CONCLUSION

Comparing nerve grafting and nerve transfer for NBPP, there is no statistically significant difference in functional elbow flexion recovery.

Early nerve repair in traumatic brachial plexus injuries in adults: treatment algorithm and first experiences

OBJECTIVE

The object of this study was to assess the advantages and disadvantages of early nerve repair within 2 weeks following adult traumatic brachial plexus injury (ATBPI).

METHODS

From 2009 onwards, the authors have strived to repair as early as possible extended C-5 to C-8 or T-1 lesions or complete loss of C-5 to C-6 or C-7 function in patients in whom there was clinical and radiological suspicion of root avulsion. Among a group of 36 patients surgically treated in the period between 2009 and 2011, surgical findings in those who had undergone treatment within 2 weeks after trauma were retrospectively compared with results in those who had undergone delayed treatment. The result of biceps muscle reanimation was the primary outcome measure.

RESULTS

Five of the 36 patients were referred within 2 weeks after trauma and were eligible for early surgery. Nerve ruptures and/or avulsions were found in all early cases of surgery. The advantages of early surgery are as follows: no scar formation, easy anatomical identification, and gap length reduction. Disadvantages include less-clear demarcation of vital nerve tissue and unfamiliarity with the interpretation of frozen-section examination findings. All 5 early-treatment patients recovered a biceps force rated Medical Research Council grade 4.

CONCLUSIONS

Preliminary results of nerve repair within 2 weeks of ATBPI are encouraging, and the benefits outweigh the drawbacks. The authors propose a decision algorithm to select patients eligible for early surgery. Referral standards for patients with ATBPI must be adapted to enable early surgery.

Effect of fascicle composition on ulnar to musculocutaneous nerve transfer (Oberlin transfer) in neonatal brachial plexus palsy

OBJECTIVE Neonatal brachial plexus palsy (NBPP) continues to be a problematic occurrence impacting approximately 1.5 per 1000 live births in the United States, with 10%-40% of these infants experiencing permanent disability. These children lose elbow flexion, and one surgical option for recovering it is the Oberlin transfer. Published data support the use of the ulnar nerve fascicle that innervates the flexor carpi ulnaris as the donor nerve in adults, but no analogous published data exist for infants. This study investigated the association of ulnar nerve fascicle choice with functional elbow flexion outcome in NBPP. METHODS The authors conducted a retrospective study of 13 cases in which infants underwent ulnar to musculocutaneous nerve transfer for NBPP at a single institution. They collected data on patient demographics, clinical characteristics, active range of motion (AROM), and intraoperative neuromonitoring (IONM) (using 4 ulnar nerve index muscles). Standard statistical analysis compared pre- and postoperative motor function improvement between specific fascicle transfer (1-2 muscles for either wrist flexion or hand intrinsics) and nonspecific fascicle transfer (> 2 muscles for wrist flexion and hand intrinsics) groups. RESULTS The patients' average age at initial clinic visit was 2.9 months, and their average age at surgical intervention was 7.4 months. All NBPPs were unilateral; the majority of patients were female (61%), were Caucasian (69%), had right-sided NBPP (61%), and had Narakas grade I or II injuries (54%). IONM recordings for the fascicular dissection revealed a donor fascicle with nonspecific innervation in 6 (46%) infants and specific innervation in the remaining 7 (54%) patients. At 6-month follow-up, the AROM improvement in elbow flexion in adduction was 38° in the specific fascicle transfer group versus 36° in the nonspecific fascicle transfer group, with no statistically significant difference (p = 0.93). CONCLUSIONS Both specific and nonspecific fascicle transfers led to functional recovery, but that the composition of the donor fascicle had no impact on early outcomes. In young infants, ulnar nerve fascicular dissection places the ulnar nerve at risk for iatrogenic damage. The data from this study suggest that the use of any motor fascicle, specific or nonspecific, produces similar results and that the Oberlin transfer can be performed with less intrafascicular dissection, less time of surgical exposure, and less potential for donor site morbidity.

A novel extradural nerve transfer technique by coaptation of C4 to C5 and C7 to C6 for treating isolated upper trunk avulsion of the brachial plexus

The study aimed to demonstrate the feasibility of an extradural nerve anastomosis technique for the restoration of a C5 and C6 avulsion of the brachial plexus. Nine fresh frozen human cadavers were used. The diameters, sizes, and locations of the extradural spinal nerve roots were observed. The lengths of the extradural spinal nerve roots and the distance between the neighboring nerve root outlets were measured and compared in the cervical segments. In the spinal canal, the ventral and dorsal roots were separated by the dura and arachnoid. The ventral and dorsal roots of C7 had sufficient lengths to anastomose those of C6. The ventral and dorsal of C4 had enough length to be transferred to those of C5, respectively. The feasibility of this extradural nerve anastomosis technique for restoring C5 and C6 avulsion of the brachial plexus in human cadavers was demonstrated in our anatomical study.

An Update on the Management of Neonatal Brachial Plexus Palsy-Replacing Old Paradigms: A Review

IMPORTANCE

Neonatal brachial plexus palsy (NBPP) can result in persistent deficits for those who develop it. Advances in surgical technique have resulted in the availability of safe, reliable options for treatment. Prevailing paradigms include, "all neonatal brachial plexus palsy recovers," "wait a year to see if recovery occurs," and "don't move the arm." Practicing by these principles places these patients at a disadvantage. Thus, the importance of this review is to provide an update on the management of NBPP to replace old beliefs with new paradigms.

OBSERVATIONS

Changes within denervated muscle begin at the moment of injury, but without reinnervation become irreversible 18 to 24 months following denervation. These time-sensitive, irreversible changes are the scientific basis for the recommendations herein for the early management of NBPP and put into question the old paradigms. Early referral has become increasingly important because improved outcomes can be achieved using new management algorithms that allow surgery to be offered to patients unlikely to recover sufficiently with conservative management. Mounting evidence supports improved outcomes for appropriately selected patients with surgical management compared with natural history. Primary nerve surgery options now include nerve graft repair and nerve transfer. Specific indications continue to be elucidated, but both techniques offer a significant chance of restoration of function.

CONCLUSIONS AND RELEVANCE

Mounting data support both the safety and effectiveness of surgery for patients with persistent NBPP. Despite this support, primary nerve surgery for NBPP continues to be underused. Surgery is but one part of the multidisciplinary care of NBPP. Early referral and implementation of multidisciplinary strategies give these children the best chance of functional recovery. Primary care physicians, nerve surgeons, physiatrists, and occupational and physical therapists must partner to continue to modify current treatment paradigms to provide improved quality care to neonates and children affected by NBPP.

Quantitative Dixon MRI sequences to relate muscle atrophy and fatty degeneration with range of motion and muscle force in brachial plexus injury

BACKGROUND

Assessment of muscle atrophy and fatty degeneration in brachial plexus injury (BPI) could yield valuable insight into pathophysiology and could be used to predict clinical outcome. The objective of this study was to quantify and relate fat percentage and cross-sectional area (CSA) of the biceps to range of motion and muscle force of traumatic brachial plexus injury (BPI) patients.

METHODS

T1-weighted TSE sequence and three-point Dixon images of the affected and non-affected biceps brachii were acquired on a 3 Tesla magnetic resonance scanner to determine the fat percentage, total and contractile CSA of 20 adult BPI patients. Regions of interest were drawn by two independent investigators to determine the inter-observer reliability. Paired Students' t-test and multivariate analysis were used to relate fat percentage, total and contractile CSA to active flexion and biceps muscle force.

RESULTS

The mean fat percentage 12±5.1% of affected biceps was higher than 6±1.0% of the non-affected biceps (p<0.001). The mean contractile CSA 8.1±5.1cm² of the affected biceps was lower than 19.4±4.9cm² of the non-affected biceps (p<0.001). The inter-observer reliability was excellent (ICC 0.82 to 0.96). The contractile CSA contributed most to the reduction in active flexion and muscle force.

CONCLUSION

Quantitative measurement of fat percentage, total and contractile CSA using three-point Dixon sequences provides an excellent reliability and relates with active flexion and muscle force in BPI.

The SPA arrangement of the branches of the upper trunk of the brachial plexus: a correction of a longstanding misconception and a new diagram of the brachial plexus

OBJECT

Brachial plexus (BP) diagrams in most textbooks and papers represent the branches and divisions of the upper trunk (UT) in the following sequence from cranial to caudal: suprascapular nerve, anterior division, and then posterior division. This concept contradicts what is seen in the operating room and is noticed by most peripheral nerve surgeons. This cadaveric study was conducted to look specifically at the exact pattern of branching of the upper trunk of the BP.

METHODS

Ten cadavers (20 BPs) were dissected. Both supra- and infraclavicular exposures were performed. The clavicle was retracted or resected to identify the divisions of the BP. A posterior approach was used in 2 cases.

RESULTS

In all dissections the origin of the posterior division was in a more cranial and dorsal plane in relation to the anterior division. In most dissections the supra scapular nerve branched off distally from the UT, giving it the appearance of a trifurcation, taking off just cranial and dorsal to the posterior division. The branching pattern of the UT consistently had the following sequential arrangement from cranial and posterior to caudal and anterior: suprascapular nerve (S), posterior division (P), and anterior division (A), hence the acronym SPA.

CONCLUSIONS

Supraclavicular exposure of the BP exposes only the trunks and divisions. Recognizing the “SPA” arrangement of the branches helps in identifying the correct targets for neurotization, especially given that these 3 branches are the most common targets for BP repair. Understanding the anatomy means better surgical planning and better patient outcomes.

International Federation of Societies for Surgery of the Hand Committee report: the role of nerve transfers in the treatment of neonatal brachial plexus palsy

Nerve transfers have gained popularity in the treatment of adult brachial plexus palsy; however, their role in the treatment of neonatal brachial plexus palsy (NBPP) remains unclear. Brachial plexus palsies in infants differ greatly from those in adults in the patterns of injury, potential for recovery, and influences of growth and development. This International Federation of Societies for Surgery of the Hand committee report on NBPP is based upon review of the current literature. We found no direct comparisons of nerve grafting to nerve transfer for primary reconstruction of NBPP. Although the results contained in individual reports that use each strategy for treatment of Erb palsy are similar, comparison of nerve transfer to nerve grafting is limited by inconsistencies in outcomes reported, by multiple confounding factors, and by small numbers of patients. Although the role of nerve transfers for primary reconstruction remains to be defined, nerve transfers have been found to be effective and useful in specific clinical circumstances including late presentation, isolated deficits, failed primary reconstruction, and multiple nerve root avulsions. In the case of NBPP more severe than Erb palsy, nerve transfers alone are inadequate to address all of the deficits and should only be considered as adjuncts if maximal re-innervation is to be achieved. Surgeons who commit to care of infants with NBPP need to avoid an over-reliance on nerve transfers and should also have the capability and inclination for brachial plexus exploration and nerve graft reconstruction.