Supercharged end-to-side anterior interosseous nerve transfer to restore intrinsic function in high ulnar nerve injury: a prospective cohort study.

BACKGROUND: High ulnar nerve injuries is known to have unfavorable motor outcomes compared to other peripheral nerve injuries in the upper extremity. Functional muscle recovery after peripheral nerve injury depends on the time to motor end plate reinnervation and the number of motor axons that successfully reach the target muscle. The purpose of this study is to assess the functional recovery, and complications following performing supercharge end-to-side (SETS) anastomosis for proximal ulnar nerve injuries. Our study focuses on the role of SETS in the recovery process of high ulnar nerve injury. PATIENT AND METHODS: This study is a prospective, single-arm, open-label, case series. The original proximal nerve pathology was dealt with according to the cause of injury, then SETS was performed distally. The follow-up period was 18 months. We compared the neurological findings before and after the procedure. A new test was used to show the effect of SETS on recovery by performing a Lidocaine proximal ulnar nerve block test. RESULTS: Recovery of the motor function of the ulnar nerve was evident in 33 (86.8%) patients. The mean time to intrinsic muscle recovery was 6.85 months ± 1.3, only 11.14% of patients restored protective sensation to the palm and finger and 86.8% showed sensory level at the wrist level at the end of the follow-up period. Lidocaine block test was performed on 35 recovered patients and showed no change in intrinsic hand function in 31 patients. CONCLUSION: SETS exhibit a remarkable role in the treatment of high ulnar nerve damage. SETS transfer can act as a nerve transfer that can supply intrinsic muscles by its fibers and allows for proximal nerve regeneration. We believe that this technique improves recovery of hand motor function and allows recovery of sensory fibers when combined with treating the proximal lesion. TRIAL REGISTRATION: Approved by Research Ethics Committee of Faculty of Medicine- Cairo University on 01/09/2021 with code number: MD-215-2021.

Positive effect of ulnar nerve fascicle transfer to musculocutaneous nerve seeded with allogeneic adipose tissue derived stem cells on nerve regeneration for repairing upper brachial plexus injury in a rat model: A preliminary study.

BACKGROUND: Traumatic peripheral nerve injury, with an annual incidence reported to be approximately 13-23 per 100,000 people, is a serious clinical condition that can often lead to significant functional impairment and permanent disability. Although nerve transfer has become increasingly popular in the treatment of brachial plexus injuries, satisfactory results cannot be obtained even with total nerve root transfer, especially after serious injuries. To overcome this problem, we hypothesize that the application of stem cells in conjunction with nerve transfer procedures may be a viable alternative to more aggressive treatments that do not result in adequate improvement. Similarly, some preliminary studies have shown that adipose stem cells combined with acellular nerve allograft provide promising results in the repair of brachial plexus injury. The purpose of this study was to assess the efficacy of combining adipose-derived stem cells with nerve transfer procedure in a rat brachial plexus injury model. METHODS: Twenty female Wistar rats weighing 300-350 g and aged 8-10 weeks were randomly divided into two groups: a nerve transfer group (NT group) and a nerve transfer combined adipose stem cell group (NT and ASC group). The upper brachial plexus injury model was established by gently avulsing the C5-C6 roots from the spinal cord with microforceps. A nerve transfer from the ulnar nerve to the musculocutaneous nerve (Oberlin procedure) was performed with or without seeded allogeneic adipose tissue-derived stem cells. Adipose tissue-derived stem cells at a rate of 2 × 106 cells were injected locally to the surface of the nerve transfer area with a 23-gauge needle. Immunohistochemistry (S100 and PGP 9.5 antibodies) and electrophysiological data were used to evaluate the effect of nerve repair 12 weeks after surgery. RESULTS: The mean latency was significantly longer in the NT group (2.0 ± 0.0 ms, 95% CI: 1.96-2.06) than in the NT and ASC group (1.7 ± 0.0 ms, 95% CI: 1.7-1.7) (p < .001). The mean peak value was higher in the NT group (1.7 ± 0.0 mV, 95% CI: 1.7-1.7) than in the NT and ASC group (1.7 ± 0.3 mV, 95% CI: 1.6-1.9) with no significant difference (p = .61). Although S100 and PGP 9.5 positive areas were observed in higher amounts in the NT and ASC group compared to the NT group, the differences were not statistically significant (p = .26 and .08, respectively). CONCLUSIONS: This study conducted on rats provides preliminary evidence that adipose-derived stem cells may have a positive effect on nerve transfer for the treatment of brachial plexus injury. Further studies with larger sample sizes and longer follow-up periods are needed to confirm these findings.

Timing of surgery in peripheral nerve injury of the upper extremity.

Peripheral nerve injuries present a complex clinical challenge, requiring a nuanced approach in surgical management. The consequences of injury vary, with sometimes severe disability, and a risk of lifelong pain for the individual. For late management, the choice of surgical techniques available range from neurolysis and nerve grafting to tendon and nerve transfers. The choice of technique utilized demands an in-depth understanding of the anatomy, patient demographics and the time elapsed since injury for optimized outcomes. This paper focuses on injuries to the radial, median and ulnar nerves, outlining the authors' approach to these injuries.Level of evidence: IV.

Modification of the Zancolli Lasso Procedure for Simultaneous Correction of Wartenberg's Sign.

Ulnar nerve injury initiates an imbalance between the intrinsic muscles and extrinsic extensors of the ring and small fingers, which leads to the characteristic hyperextension of the metacarpophalangeal (MP) joints and flexion of the proximal interphalangeal joints of these 2 digits-commonly referred to as the ulnar claw hand. In addition to these changes in the static posture of the hand, ulnar nerve palsy severely impairs grasp due to deficient active MP joint flexion. In most cases, motor balance can be restored by preventing MP joint hyperextension and augmenting MP joint flexion using the Zancolli lasso procedure (ZLP). Ulnar neuropathy can cause a second motor imbalance between the ulnar intrinsics and the extensor digit minimi leading to an abduction deformity of the small finger known as Wartenberg's sign. The inability to adduct the small finger can be a great source of frustration to patients. Using a cadaveric biomechanical model, we have developed a simple modification of the Zancolli lasso procedure that simultaneously corrects claw deformity and Wartenberg's sign and we report its efficacy in 2 clinical cases.

Outcomes of radiocarpal pinning to facilitate nerve repair in wrist-level ulnar nerve injuries with defect.

BACKGROUND: The ideal scenario for ulnar nerve repair is primary end-to-end neurorrhaphy in a tension-free environment. However, this could be complicated by soft tissue loss, scarring, and neuroma formation in a delayed injury, creating a nerve defect. With a wrist-level nerve defect, a flexion position can help shorten the nerve gap; however, maintaining the position can be challenging intraoperatively and postoperatively. METHODS: Previously, we proposed our method of using a 1.6-mm K wire for radius-lunate-capitate pinning of the wrist in flexion to minimize the nerve gap, thereby facilitating neuroma excision and end-to-end neurorrhaphy in delayed ulnar nerve injury. In this study, we elaborate our method and present our case series. RESULTS: From October 2018 to July 2020, five patients (mean age: 48.2 years; mean delay from injury to surgery: 84.6 days; mean follow-up: 17.5 months) were retrospectively reviewed. The mean flexion fixation angle was 52°, and the K wire was removed at an average of 5.1 weeks postoperatively. All patients were followed up for a minimum of 12 months. All patients achieved M4 and S3 or S3+ neurologically (according to the criteria of the Nerve Injuries Committee of the British Medical Research Council). The mean disabilities arm, shoulder, and hand score was 14.1. The mean grasp and pinch strengths were, respectively, 76.8% and 63.6% of the contralateral hand. All wrist range of motion returned to normal within 12 weeks. No complications were noted intraoperatively or postoperatively. CONCLUSION: Our study showed that radiocarpal pinning of the wrist in flexion was safe and convenient to minimize the nerve gap and to facilitate end-to-end neurorrhaphy in limited-sized wrist-level ulnar nerve defects.

Tendon Transfer versus Nerve Transfer for the Reconstruction of Key Pinch and Grip Strength in Isolated High Traumatic Injuries of the Ulnar Nerve: A Systematic Review.

Background: Primary repair for traumatic injuries to the ulnar nerve alone does not always restore satisfactory hand function, particularly in injuries above the elbow where the long distances for regeneration limit motor reinnervation. Reductions in key pinch and grip strength are some of the main complaints. Tendon transfers have traditionally been used to improve key pinch and grip strength as a late salvage where primary nerve regeneration has run its course. Nerve transfers have been proposed as an alternative procedure and may be offered early to augment recovery, lengthen the window for reinnervation or provide motor reinnervation where the results of nerve repair are expected to be poor. This review sought to identify whether one type of procedure was superior to the other for reconstructing key pinch and grip strength. Methods: Medline, Embase and Cochrane Library were searched to identify articles that concerned nerve or tendon transfer following isolated traumatic injury to the ulnar nerve. Articles were excluded if patients had polytrauma or degenerative diseases of the peripheral nerves. Results: A total of 179 articles were screened for inclusion. And 35 full-text articles were read and assessed for eligibility, of which seven articles were eligible. Following citation search, two additional articles were included. Five tendon transfer articles and four nerve transfer articles were included. Key pinch and grip strength outcomes for both procedures were roughly similar, though tendon transfers carried a much higher risk of complications. Conclusions: Based on the key pinch and grip strength outcomes, tendon transfer and nerve transfer restore a similar degree of function following traumatic ulnar injury. Reported nerve transfer outcomes for grip strength were slightly better. Return to useful function was faster following tendon transfers. Preoperative data and more patient-reported outcome measures should be recorded in future studies to provide more context for each procedure type. Level of Evidence: Level III (Therapeutic).

Ulnar Nerve Neuropathy After Surgery for Intraarticular Distal Humerus Fractures: An Analysis of 116 Patients.

PURPOSE: To identify the incidence and the factors associated with a postoperative ulnar nerve neuropathy in patients who had undergone open reduction and internal fixation for intraarticular distal humerus fractures. METHODS: We retrospectively reviewed 116 patients who had undergone surgery between January 2011 and December 2020. Age, sex, BMI, mechanism of injury, open or closed fracture, operation time, tourniquet time, and nerve injury at the final examination were collected from medical charts. We essentially used the paratricipital approach. In cases in which the reduction of intraarticular bone fragments was difficult, olecranon osteotomy was used. Ulnar nerve function was graded according to a modified system of McGowan. We conducted logistic regression analysis to investigate factors of neuropathy using items identified as statistically significant in univariate analysis as explanatory variables. RESULTS: Thirty-four patients (29.3%) had persistent neuropathy at the final follow-up. In the modified McGowan classification, 28 patients had grade 1 and 6 patients had grade 2 neuropathy. Olecranon osteotomy emerged as a distinct explanatory variable for the prophylaxis of ulnar nerve neuropathy in the multivariate analysis (odds ratio, 0.30; 95% confidence interval, 0.12-0.73). Anterior transposition, however, was not a statistically significant factor (odds ratio, 1.91; 95% confidence interval, 0.81-4.56). CONCLUSIONS: Olecranon osteotomy was the only independent factor associated with preventing the occurrence of ulnar nerve neuropathy. Ulnar nerve transposition might not be associated with prevention of ulnar nerve neuropathy. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.

Primary Repair versus Reverse End-to-Side Coaptation by Anterior Interosseous Nerve Transfer in Proximal Ulnar Nerve Injuries.

BACKGROUND: Proximal ulnar nerve lacerations are challenging to treat because of the complex integration of sensory and motor function in the hand. The purpose of this study was to compare primary repair and primary repair plus anterior interosseous nerve (AIN) reverse end-to-side (RETS) coaptation in the setting of proximal ulnar nerve injuries. METHODS: A prospective cohort study was performed of all patients at a single, academic, level I trauma center from 2014 to 2018 presenting with isolated complete ulnar nerve lacerations. Patients underwent either primary repair (PR) only or primary repair and AIN RETS (PR + RETS). Data collected included demographic information; quick Disabilities of the Arm, Shoulder and Hand questionnaire score; Medical Research Council score; grip and pinch strength; and visual analogue scale pain scores at 6 and 12 months postoperatively. RESULTS: Sixty patients were included in the study: 28 in the PR group and 32 in the RETS + PR group. There was no difference in demographic variables or location of injury between the two groups. Average quick Disabilities of the Arm, Shoulder and Hand questionnaire scores for the PR and PR + RETS groups were 65 ± 6 and 36 ± 4 at 6 months and 46 ± 4 and 24 ± 3 at 12 months postoperatively, respectively, and were significantly lower in the PR + RETS group at both points. Average grip and pinch strength were significantly greater for the PR + RETS group at 6 and 12 months. CONCLUSION: This study demonstrated that primary repair of proximal ulnar nerve injuries plus AIN RETS coaptation yielded superior strength and improved upper extremity function when compared with PR alone. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

Medial-lateral versus lateral-only pinning fixation in children with displaced supracondylar humeral fractures: a meta-analysis of randomized controlled trials.

BACKGROUND: Supracondylar humeral fractures (SCHFs) are frequent in children, and closed reduction with percutaneous pin fixation remains the standard surgical treatment for displaced SCHFs. Two pinning configurations, medial-lateral crossed entry pinning (MLP) and lateral-only entry pinning (LP), are widely used, but which one is superior to another one is still debatable. This meta-analysis aimed to compare the efficacy and safety of both pinning fixation methods. METHODS: Randomized controlled trials (RCTs) were searched on PubMed, EMBASE, Web of Science, Cochrane library and Google Scholar. Relative risk (RR) and mean difference (MD) with corresponding 95% confidence interval (CI) were calculated for radiographical outcomes, functional outcomes and complications. RESULTS: A total of 19 RCTs comprising 1297 Gartland type II and type III fractures were included. MLP had a decreased risk of loss of reduction (RR = 0.70, 95%CI 0.52-0.94, P = 0.018) but a higher risk of iatrogenic ulnar nerve injury (RR = 2.21, 95%CI 1.11-4.41, P = 0.024) than LP. However, no significant difference was observed for incidence of ulnar nerve injury if applying a mini-open technique in MLP group (RR = 1.73, 0.47-6.31, P = 0.407). There were no differences between both groups in loss of carrying angle (MD = - 0.12, 95%CI - 0.39 to 0.16), loss of Baumann angle (MD = 0.08, 95%CI - 0.15 to 0.30), excellent grading of Flynn criteria (RR = 1.06, 95%CI 0.99-1.14, P = 0.102) and pin tract infection (RR = 0.92, 95%CI 0.50-1.70). CONCLUSIONS: MLP is more effective in maintaining fixation, while LP is safer with respect to ulnar nerve injury. MLP with a mini-open technique reduces the risk of ulnar nerve lesion and is an effective and safe choice.

Bilateral Ulnar Nerve Injury in the Wrist: Comparison of First Webspace Muscle Reconstruction by Opponens Nerve Transfer in the Right Hand Versus Direct Ulnar Nerve Repair in the Left Hand.

We report a case of a bilateral glass injury to the wrist with transection of flexor tendons and the ulnar nerve and artery in a 60-year-old male patient. Two days after his accident, we repaired all divided structures, and on the right hand, we added the transfer of the opponens motor branch to the deep terminal division of the ulnar nerve aimed at first dorsal interosseous and adductor pollicis muscle reinnervation. After surgery, the patient was followed over 24 months. Postoperative dynamometry of the hand, which included grasping, key-pinch, subterminal-key-pinch, pinch-to-zoom, and first dorsal interosseous muscle strength, indicated recovery only in the nerve transfer side.

Multidisciplinary treatment and functional outcome evaluation of combined injuries of nerves, vessels, and flexor tendons: spaghetti wrist.

OBJECTIVE: In this study, we aimed to evaluate the effectiveness of the modified Kessler technique in managing spaghetti wrist lacerations by multidisciplinary treatment. PATIENTS AND METHODS: Patients who were operated and followed up with the diagnosis of spaghetti wrist tears in our clinic between January 2012 and December 2020 were included in the study. In the postoperative follow-ups, the parameters evaluating the functionality of the patients were examined. RESULTS: Patients were 105 male (86.7%) and 16 women (13.2%), with a mean age of 36.83 ± 16.38 years. At the final follow-up, functional outcomes were assessed. The most common injury mechanism was glass-related injuries (35.5%). The mean starting surgery time of the patients was 4.64±2.98 hours. The most frequently involved structures were the palmaris longus with a rate of 51% and the flexor digitorum superficialis with a rate of 45%. There were significant differences regarding intrinsic function and grip strength between male and female patients (p = 0.04, p = 0.21, respectively). There were significant differences regarding sensation and grip strength between smoker and nonsmoker patients (p = 0.03, p = 0.01, respectively). The number of the damaged structures was negatively correlated with postsurgical functional outcomes of four tests, including tendon function, opposition, intrinsic function, and grip strength. The physical therapy period was correlated to hand function tests (r = 0.756, p < 0.05). Nerve damage was negatively correlated with sensation (p = 0.011, r = -0.932). CONCLUSIONS: The modified Kessler technique is reliable with functional outcomes for spaghetti wrist injuries involving tendons, nerves, and arteries. Meticulous and early surgical treatment within the first 8 hours of spaghetti wrist injury and early initiation and long-term physical therapy are vital in patients' functional outcomes.

Supracondylar Humerus Fractures in Infants and Early Toddlers; Characteristics, Clinical and Radiological Outcomes Compared with Older Children.

BACKGROUND: Supracondylar humerus fractures (SCHF) are rarely seen in the youngest age groups (1-3 years). Although there is no difference in the context of treatment options, it has been shown that younger age groups have different characteristics. Few studies have examined toddlers, which have notably different characteristics. This study is the first to report the characteristics, diagnosis, treatment and functional results of SCHF in infants and early toddlers. METHODS: A retrospective analysis was made of the data of patients younger than 30 months old, who were operated on in our clinic for SCHF between 2012 and 2020 with at least 2 years of follow-up. Patient demographic and surgical data, and the functional and radiological results were documented. RESULTS: Evaluation was made of a total of 52 patients comprising 30 females (58%) and 22 males (42%), with a mean age of 20.75 ± 5.4 months (range, 6-30 months). The injury was in the right elbow in 24 (46%) patients. The mechanism of injury was a fall from an object at home (table, chair, bed, etc.) in 41 (79%) patients. Patients who fell from a height of more than 4 meters had additional injuries (liver laceration, vertebral fracture, etc.). Only 1 patient had anterior interosseous nerve (AIN) damage before the operation, but the final follow-up neurovascular examinations for all patients were normal. The median follow-up period was 4 years (range, 2-7 years). Flynn outcome scores were (88.5%) excellent and variant Hospital for Special Surgery scores were (82.7%) excellent. CONCLUSIONS: With appropriate treatment of SCHF, the clinical outcomes in infants and early toddlers are excellent. Using a medial pin to achieve and protect stability in this age group does not increase the risk of iatrogenic ulnar nerve damage. Patients younger than 20 months tend to have more varus malalignment but similar functional results.

The Gantzer transfer - Assessment of the feasibility of using the nerve supplying the Gantzer muscle for end-to-side supercharging of the ulnar nerve.

Our study aimed at assessing the anatomical feasibility of using the nerve supplying the Gantzer muscle (GM) to supercharge the ulnar nerve following injury. The GM nerve was dissected and measured in 36 forearms. The distance between its origin and the lateral epicondyle of humerus and between the GM nerve and the ulnar nerve was measured. The GM was present in 15 forearms (47%). The average distance between the origin of the GM nerve and the lateral epicondyle was 7.34 cm (range 3.3-9.1 cm). The average length of the GM nerve was 3.05 cm (range 1.6-4.5 cm) from origin to neuromuscular junction. The average distance from the ulnar nerve was 2.56 cm (range 1.8-13 3.4 cm). The length of the GM nerve was significantly greater (p < 0.05) than the perpendicular distance between its origin and the ulnar nerve, allowing ample margin for side-to-side or end-to-side supercharging of the ulnar nerve with minimal or no need for further translocation or dissection. The use of the GM nerve as donor following ulnar nerve injury may provide an alternative to the pronator quadratus nerve for supercharged end-to-side transfer, or as an addition, thus supercharging the ulnar nerve twice.

Ulnar Nerve Injury Following Distal Radius Fracture Assessed by Ultrasonography: Management of an Ulnar Nerve Lesion.

A fracture of the distal radius with an associated injury to the ulnar nerve is rare. The management of the ulnar nerve lesion is unclear. We present a patient with a closed distal radius fracture related to an injury to the ulnar nerve associated with diminished sensation and a claw deformity. This was assessed by ultrasonography (US) that showed the nerve to be in continuity without any evidence of compression. The nerve was deviated towards the volar side at the distal end of the ulna and was enlarged at the same point. Open reduction and internal fixation was performed for the fracture. Emergent nerve exploration was not performed. The function of the ulnar nerve was completely restored at 16 weeks after injury. In cases presenting with ulnar nerve injury, we recommend US to evaluate the condition of the ulnar nerve. Nerve exploration should be performed when neurological deficits were found on US or symptoms did not recover over 4 months observation. Level of Evidence: Level V (Therapeutic).

Combined Use of Chitosan-PGLA Nerve Grafts and Bone Marrow Mononuclear Cells to Repair a 50-mm-long Median Nerve Defect Combined with an 80-mm-long Ulnar Nerve Defect in the Human Upper Arm.

BACKGROUND: Severe peripheral nerve injury, especially the long-distance peripheral nerve defect, causes severe functional disability in patients. There is always a lack of effective repair methods for clinic, and those in practice are associated with side effects. A case study was performed to observe the regenerative outcomes of the surgical repair of long-distance peripheral nerve defects in the upper arm with chitosan-poly(glycolide-co-lactide) (PGLA) nerve grafts combined with bone marrow mononuclear cells (BMMCs). METHODS: The right upper arm of a 29-year-old woman was injured, leaving a 50-mm-long median nerve defect, an 80-mm-long ulnar nerve defect, and muscle and blood vessel disruptions. The nerve defects were repaired by implanting BMMC-containing chitosan-PGLA nerve grafts on the 40th day after injury. A series of functional assessments were carried out from 2 weeks to 66 months after surgical repair. Sensory function was assessed by the pinprick test, two-point discrimination test and Semmes-Weinstein monofilament test. Motor function was evaluated by the range of motion of the wrist joint and muscle power. Autonomic function was monitored by laser-Doppler perfusion imaging (LDPI). Tissue morphology was observed through ultrasonic investigations. RESULTS: No adverse events, such as infection, allergy, or rejection, caused by the treatment were detected during the follow-up period. Sensory and pinprick nociception in the affected thumb, index, and middle fingers gradually restored at 6th month after surgery. The monofilament tactile sensation was 0.4 g in the terminal finger pulp of the thumb and index finger, 2.0 g in the middle finger, and greater than 300 g in the ring finger and little finger at the 66th month. Motor function recovery was detected at the 5th month after surgery, when the muscle strength of the affected forearm flexors began to recover. At the 66th month after surgery, the patient's forearm flexor strength was grade 4, with 80° of palmar flexion, 85° of dorsal extension, 8° of radial deviation, 40° of ulnar deviation, 40° of anterior rotation, and 85° of posterior rotation of the affected wrist. The patient could perform holding, picking up, and some other daily activities with the affected hand. The patient's sweating function of the affected hand was close to the level of the healthy hand. LDPI showed that the skin blood flow perfusion was significantly increased, with perfusion similar to on the normal side in some areas. Neuromusculoskeletal ultrasonography showed the presence of nerve structures. CONCLUSION: These results suggest that chitosan-PGLA nerve grafts combined with BMMCs could effectively repair long-distance nerve defects and achieve good clinical results.