Parsonage-Turner syndrome, affecting suprascapular nerve and especially to infraspinatus muscles after COVID-19 vaccination in a professional wrestler, a case report and literature review of causes and treatments.

BACKGROUND: Acute peripheral neuropathy, also known as Parsonage-Turner syndrome or neuralgic amyotrophy, mostly affects the upper brachial plexus trunks, which include the shoulder girdle. It is typically accompanied by abrupt, intense pain, weakness, and sensory disruption. The etiology and causes of this disease are still unknown because of its low prevalence, however viral reactions-induced inflammation is one of its frequent causes. CASE PRESENTATION: Here, we introduce a professional wrestler patient who was diagnosed with PTS after vaccination and was treated, and we review some articles in this field. CONCLUSION: When it comes to shoulder-girdle complaints and pain, Parsonage-Turner syndrome can be a differential diagnosis. Corticosteroids during the acute period, followed by physical therapy, appear to be an efficient way to manage pain, inflammation, muscular atrophy, and the process of recovering to full nerve regeneration.

Astrocyte reactivity in the glia limitans superficialis of the rat medial prefrontal cortex following sciatic nerve injury.

The glia limitans superficialis (GLS) on the rodent cortical surface consists of astrocyte bodies intermingled with their cytoplasmic processes. Many studies have observed astrocyte reactivity in the medial prefrontal cortex (mPFC) parenchyma induced by a peripheral nerve injury, while the response of GLS astrocytes is still not fully understood. The aim of our study was to identify the reactivity of rat GLS astrocytes in response to sciatic nerve compression (SNC) over different time periods. The alteration of GLS astrocyte reactivity was monitored using immunofluorescence (IF) intensities of glial fibrillary acidic protein (GFAP), glutamine synthetase (GS), and NFκBp65. Our results demonstrated that SNC induced GLS astrocyte reactivity seen as increased intensities of GFAP-IF, and longer extensions of cytoplasmic processes into lamina I. First significant increase of GFAP-IF was observed on post-operation day 7 (POD7) after SNC with further increases on POD14 and POD21. In contrast, dynamic alteration of the extension of cytoplasmic processes into lamina I was detected as early as POD1 and continued throughout the monitored survival periods of both sham and SNC operations. The reactivity of GLS astrocytes was not associated with their proliferation. In addition, GLS astrocytes also displayed a significant decrease in GS immunofluorescence (GS-IF) and NFκB immunofluorescence (NFκB-IF) in response to sham and SNC operation compared with naïve control rats. These results suggest that damaged peripheral tissues (following sham operation as well as peripheral nerve lesions) may induce significant changes in GLS astrocyte reactivity. The signaling mechanism from injured peripheral tissue and nerve remains to be elucidated.

Stem Cells and Tissue Engineering-Based Therapeutic Interventions: Promising Strategies to Improve Peripheral Nerve Regeneration.

Unlike the central nervous system, the peripheral one has the ability to regenerate itself after injury; however, this natural regeneration process is not always successful. In fact, even with some treatments, the prognosis is poor, and patients consequently suffer with the functional loss caused by injured nerves, generating several impacts on their quality of life. In the present review we aimed to address two strategies that may considerably potentiate peripheral nerve regeneration: stem cells and tissue engineering. In vitro studies have shown that pluripotent cells associated with neural scaffolds elaborated by tissue engineering can increase functional recovery, revascularization, remyelination, neurotrophin expression and reduce muscle atrophy. Although these results are very promising, it is important to note that there are some barriers to be circumvented: the host's immune response, the oncogenic properties attributed to stem cells and the duration of the pro-regenerative effects. After all, more studies are still needed to overcome the limitations of these treatments; those that address techniques for manipulating the lesion microenvironment combining different therapies seem to be the most promising and proactive ones.

Conduction blocks of the median nerve at the wrist in pregnancy and postpartum carpal tunnel syndromes.

INTRODUCTION/AIMS: The aim in this study is to describe the clinical and electrophysiological patterns of pregnancy-related carpal tunnel syndrome (PRCTS) occurring during pregnancy or after delivery. METHODS: Clinical, epidemiological, and electrodiagnostic (EDx) data were studied in 130 women with PRCTS onset during pregnancy (n = 80) or after delivery (n = 50). Twenty-six women with PRCTS underwent EDx analysis during pregnancy and 104 after delivery (83 within 6 months of delivery and 21 up to 24 months after pregnancy onset). PRCTS was compared with idiopathic CTS in a control group consisting of 57 age-matched women with 98 cases of CTS. Twenty-four women with PRCTS had clinical and electrophysiological follow-up after corticosteroid injection (CSI) at the wrist. RESULTS: Clinical analysis showed a higher rate of bilateral and diurnal/permanent paraesthesia and more severe symptoms in PRCTS compared with idiopathic CTS. EDx analysis showed more severe abnormalities in classical tests and a higher rate of conduction block (CB) in PRCTS. Statistical analysis showed a strong negative correlation between the incidence and importance of CB and the time interval at which PRCTS women underwent EDx examination, between pregnancy onset and 24 months later. CSI resulted in significant clinical and EDx improvement in 22 of 24 PRCTS women, with disappearance of all motor and most sensory CBs. DISCUSSION: The EDx pattern of PRCTS is an acute/subacute median nerve lesion at the wrist identified by many CBs. This occurs concurrently with hormonal changes, is responsible for more severe clinical symptoms and EDx data, and it explains why CSI is so effective.

Ultrasound-guided-electromyography in plegic muscle: Usefulness of nerve stimulation.

INTRODUCTION/AIMS: In traumatic nerve lesions (TNLs), motor unit potentials (MUPs) may be difficult to detect in early injury. Ultrasound-guided electromyography (US-EMG) can aid in identifying areas of muscle activation, but its sensitivity can be improved. In this study we compare the sensitivity of US-EMG alone with US-EMG after peripheral nerve stimulation (NC-US-EMG) to better identify active muscle regions. METHODS: In this prospective study, 32 patients with severe TNLs were evaluated with standard EMG (ST-EMG), US-EMG, and NC-US-EMG at baseline (T0), after 2 to 3 months (T1), and after 5 to 6 months (T2). RESULTS: NC-US-EMG was more sensitive in detecting MUPs compared with US-EMG and ST-EMG at T0 (19 patients vs 14 and 5 patients, respectively). In addition, both US-guided techniques were more sensitive than ST-EMG in detecting MUPs (ST-EMG vs US-EMG: P = .014; ST-EMG vs NC-US-EMG: P = .003). At T1, ST-EMG remained less sensitive NC-US-EMG (P = .019). No significant differences were observed among the three techniques at T2. DISCUSSION: In the evaluation of severe TNLs, the combination of peripheral nerve stimulation and US increases the sensitivity of EMG for MUP detection at baseline and 2 to 3 months postinjury.

Two fingerbreadths, one finger's width: on the proximity of the radial nerve to the deltoid tuberosity.

INTRODUCTION: The aim of this study was to find a convenient technique to evaluate the location of the radial nerve (RN) with reference to the deltoid tuberosity (DT). MATERIALS AND METHODS: Sixty-eight upper extremities, embalmed using a modified version of Thiel's method, were included in the study. The interval between the tip of the greater tubercle of the humerus and the distal tip of the lateral humeral epicondyle (LE) was defined as humeral length (HL). The most prominent point of the DT was used as the point of reference. Through this point, a horizontal reference line which met the humeral axis at the dorsal side of the humeral shaft was simulated. The longitudinal distance between the crossing point of the horizontal line and the humeral axis and the RN was measured (distance 1). The interval between the intersection point and the reference point at the DT was measured (distance 2). Data were evaluated in centimeters. RESULTS: For the whole sample, the HL averaged 31.0 cm (SD: 2.3; range 26.2-36.9). Distance 1 averaged 2.2 cm (SD: 0.3; range 1.6-3.1), and distance 2 averaged 1.2 cm (SD: 1.0; range 0-2.8). The HL was larger in the male group when compared to females (p < 0.001; males mean: 32.2 cm; females mean 29.5 cm). There was no difference regarding distance 2 (p = 0.59; males mean: 1.2 cm; females mean: 1.3 cm) between the sexes. Distance 1 was significantly (p = 0.02) larger in the male group (mean: 2.3 cm) when compared to females (mean: 2.1 cm). Concerning sides, there were no differences regarding all evaluated parameters (HL: p = 0.6; Distance 1: p = 0.6; distance 2: p = 0.8). CONCLUSIONS: This study provides an easily applicable technique to localize the RN with reference to the DT.

Activity-dependent decline and recovery of synaptic transmission in central parts of surviving primary afferents after their peripheral cut in crayfish.

Axons deprived of their nucleus degenerate within a few days in mammals but survive for several months in crustaceans. However, it is not known whether central synapses from sensory axons may preserve their molecular machinery in the absence of spiking activity. To assess this, we used peripheral axotomy, which removes their nuclei combined with electrophysiology techniques and electron microscopy imaging. We report the following. (1) Electron microscopy analysis confirms previous observations that glial cell nuclei present in the sensory nerve proliferate and migrate to axon tubes, where they form close contacts with surviving axons. (2) After peripheral axotomy performed in vivo on the coxo-basipodite chordotonal organ (CBCO), the sensory nerve does not convey any sensory message, but antidromic volleys are observed. (3) Central synaptic transmission from the CBCO to motoneurons (MNs) progressively declines over 200 days (90% of monosynaptic excitatory transmission is lost after 3 weeks, whereas 60% of disynaptic inhibitory transmission persists up to 6 months). After 200 days, no transmission is observed. (4) However, this total loss is apparent only because repetitive electrical stimulation of the sensory nerve in vitro progressively restores first inhibitory post-synaptic potentials and then excitatory post-synaptic potentials. (5) The loss of synaptic transmission can be prevented by in vivo chronic sensory nerve stimulation. (6) Using simulations based on the geometric arrangements of synapses of the monosynaptic excitatory transmission and disynaptic inhibitory pathways, we show that antidromic activity in the CBCO nerve could play a role in the maintenance of synaptic function of inhibitory pathways to MNs, but not monosynaptic excitatory transmission to MNs. Our study confirms the deep changes in glial nuclei observed in axons deprived of their nucleus. We further show that the machinery for spike conduction and synaptic release persists for several months, even if there is no longer any activity. Indeed, we were able to restore, with electrical activity, spike conduction and synaptic function after long silent periods (>6 months).

[Compromising due to additive cerclages : Can surgical treatment of humeral shaft fractures cause damage to the radial nerve?] / Kompromittierung durch additive Cerclagen : Ist der N. radialis in der operativen Versorgung der Humerusschaftfraktur in Gefahr?

BACKGROUND: In many cases the treatment of humeral shaft fractures is challenging and despite the large diversity of available approaches, no standard treatment exists. In addition to conservative treatment, intramedullary nails and plate osteosynthesis are competing methods for healing humeral shaft fractures. Furthermore, cerclage is considered to be an additive treatment for spiral fractures; however, this also increases the risk of radial nerve neuropathy and is said to compromise the perfusion of bone fragments. The goal of this study was to investigate secondary radial nerve neuropathy using additive and limited invasive cerclages for nail osteosynthesis of humeral shaft fractures. METHODS: In the present study a total of 102 patients with humeral shaft fractures were clinically and neurologically re-examined after having been treated with nail osteosynthesis and additive cerclage via a limited invasive access over the past 5 years. In total 193 cerclages with limited invasive access were inserted during this time period. RESULTS AND CONCLUSION: Of the patients four (3.9%) showed a secondary radial neuropathy during operative stabilization. Neurophysiological and neurosonographic examinations revealed that this had not been caused by compromising, embedding or severance of the radial nerve due to the cerclage. Two out of these nerve lesions recovered spontaneously within 3 and 6 months, respectively. The other two cases could not be documented over a period of 12 months due to death of the patient. With 3.9% of iatrogenic radial nerve lesions the rate of nerve lesions falls into the lower range of that which has previously been described in the literature for nerve lesions due to operative treatment of humeral shaft fractures (3-12%). We thus conclude that there is no increased risk for iatrogenic injury of the radial nerve using additive and limited invasive cerclage.

Does granulocyte-colony stimulating factor stimulate peripheral nerve regeneration? An experimental study on traumatic lesion of the sciatic nerve in rats.

AIM OF THE STUDY: To analyse the therapeutic potential of granulocyte-colony stimulating factor (G-CSF) treatment using a rat model of traumatic sciatic nerve lesion. CLINICAL RATIONALE FOR THE STUDY: G-CSF has proven strong neurotrophic properties in various models of ischaemic and traumatic brain injury. Fewer studies exist regarding the influence of G-CSF on posttraumatic peripheral nerve regeneration. Currently, the possibilities of pharmacological prevention or treatment of mechanical nerve injury are limited, and there is an urgent need to find new treatment strategies applicable in clinical situations. MATERIAL AND METHODS: A controlled traumatic right sciatic nerve lesion was set using a waterjet device. Three treatment groups were created. In the first group, G-CSF was administered after sciatic nerve injury. The second group received G-CSF before and after trauma, while the third group was treated with glucose 5%-solution. Sciatic nerve function was assessed clinically and electrophysiologically at day 1, and after weeks 1, 2, 4 and 6. Additionally, α-motoneurons of the spinal cord and sciatic nerve fibres were counted at week 6. RESULTS: Clinically, rats in both G-CSF groups improved faster compared to the control group. Additionally, animals treated with G-CSF had a significantly better improvement of motor potential amplitude and motor nerve conduction velocity at week 6 (p < 0.05). Histologically, G-CSF treatment resulted in a significantly higher number of α-motoneurons and small myelinated nerve fibres compared to placebo treatment (p < 0.05). CONCLUSIONS AND CLINICAL IMPLICATIONS: Under G-CSF treatment, the recovery of motor nerve conduction velocity and amplitude was enhanced. Further, signs of nerve regeneration and preservation of α-motoneurons were observed. These results indicate that G-CSF might accelerate and intensify the recovery of injured nerves. Thus, treatment with G-CSF may be beneficial for patients with peripheral nerve damage, and should be explored in further clinical studies.

Comparison Between Supercharged Ulnar Nerve Repair by Anterior Interosseous Nerve Transfer and Isolated Ulnar Nerve Repair in Proximal Ulnar Nerve Injuries.

PURPOSE: To compare combined ulnar nerve repair with supercharged end-to-side anterior interosseous nerve to ulnar motor nerve transfer (UR+SETS) with conventional isolated ulnar repair techniques in proximal ulnar nerve transection, with respect to intrinsic muscle power recovery and claw hand deformity correction. METHODS: We conducted a comparative matched-paired series prospectively on 21 patients with proximal ulnar nerve transection injury. Eleven patients were managed by UR+SETS and 10 by isolated ulnar repair. The outcome was reported at 3, 6, 12, and 18 months using the score of Birch and Raji and Brand's criteria. RESULTS: A total of 21 patients with acute proximal ulnar nerve transection injury had completed 18 months' follow-up. We observed better results in the UR+SETS group regarding the return of intrinsic function and reduction of deformity with earlier improvement in the score of Birch and Raji and Brand's criteria. CONCLUSIONS: In the short term, UR+SETS transfer appears to result in better intrinsic muscle reinnervation and clawing deformity correction after proximal ulnar nerve transection injury. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic II.

Neurologic deficit after reverse total shoulder arthroplasty: correlation with distalization.

BACKGROUND: Neurologic problems after reverse total shoulder arthroplasty (RTSA) have been reported, but there are a lack of studies regarding which nerve(s) are damaged and the outcomes for the patients who had neurologic complications after RTSA. The purpose of this study was to assess the prevalence and outcomes of neurologic deficit after RTSA and to evaluate the correlation between nonanatomic rearrangement of the shoulder joint and neurologic complications after RTSA. We hypothesized that the neurologic deficit was associated with excessive distalization or lateralization of the humerus after RTSA. METHODS: RTSA was performed on 182 consecutive shoulders with cuff tear arthropathy. Comparative analysis was performed on 34 shoulders with (group 1) and 148 shoulders without (group 2) neurologic deficit. RESULTS: The mean follow-up period in the study was 58.5 months (range: 24-124). The mean age was 71.5 ± 7.7 years in group 1 and 73.1 ± 7.2 years in group 2. Neurologic deficit after RTSA was found in 34 shoulders (19%). The mean postoperative acromiohumeral distance was 34.1 ± 11.0 mm in group 1 and 29.4 ± 7.6 mm in group 2 (P = .015). Significant differences in terms of postoperative distalization of the humerus were seen between group 1 (24.5 ± 9.4 mm) and group 2 (20.5 ± 8.3 mm) (P = .009). The most common forms of neurologic deficit after RTSA were axillary nerve (41.2%) and radial nerve (15%) injuries. Thirty shoulders (88%) had neuropraxia, and 4 shoulders (12%) had axonotmesis. By conservative treatment, all patients with neurologic complications achieved complete recovery without any additional surgery; the mean recovery period was 7.4 months (range: 2-38 months). CONCLUSION: Neurologic deficit occurred in 19% of patients who underwent RTSA, and it was significantly correlated with humeral distalization after surgery. Axillary nerve was mostly involved, and all patients with neurologic deficit achieved complete recovery without any additional surgery.

Incidence, diagnostics and treatment algorithm of nerve lesions after traumatic shoulder dislocations: a retrospective multicenter study.

BACKGROUND: The shoulder is the joint most prone to dislocating in the human body and accounts for 45% of all dislocations. In addition to ruptures of the soft tissue and bony injuries, lesions to vascular structures as well as the brachial plexus and its corresponding nerves might occur. With an incidence of up to 65%, nerve lesions are frequently reported after shoulder dislocations. The aim of this study is to obtain information on epidemiology, diagnostics, treatment and duration until remission or late sequelae after shoulder dislocation and concomitant nerve injury in a large patient cohort. METHODS: The patient cohort consisted of 15,739 patients from three centres who had sustained a shoulder dislocation. All patient files were searched for concomitant injury of the brachial plexus or its corresponding nerves. For epidemiological data analysis, demographic data, clinical follow-ups, electromyography and nerve conduction velocity were evaluated. RESULTS: In total, 60 patients (32 males, 28 females) with a mean age of 60 years (range 19-88 years) met the inclusion criteria. In the majority of patients (n = 51), the trauma mechanism was a trivial fall on the outstretched arm. The most frequent dislocation direction was anterior-caudal in 61.6%, followed by strictly caudal in 16.6%. The brachial plexus was injured in 46 patients (76.6%) and isolated nerve damage was documented in 14 patients (23.3%). Electroneurographic examinations were performed in less than half of the patients (38.3%). CONCLUSION: A combination injury of shoulder dislocation and plexus lesion may occur at any age and sometimes has a poor outcome. Electroneurographic examinations should be implemented when managing these patients as a cost-effective and supportive examination. LEVEL OF EVIDENCE: Level IV, retrospective study.

Comparing iatrogenic radial nerve lesions in humeral shaft fractures treated with helical or straight PHILOS plates: a 10-year retrospective cohort study of 62 cases.

BACKGROUND: Humerus shaft fractures are common and often treated surgically with a proximal humerus internal locking system like the long PHILOS® plate. Due to its close anatomical proximity to the humerus, the radial nerve is particularly susceptible to traumatic and iatrogenic damage. The iatrogenic radial nerve damage associated with internal locking systems is described in about 7% of the cases. In order to avoid this lesion, helical plates have been suggested since 1999. This technique continues to not being used as standard as there is still a clear lack of evidence. This study aimed to understand if twisting a long PHILOS plate can reduce the rate of iatrogenic radial nerve damage in humerus shaft fractures. METHODS: In this 10-year retrospective comparative study, patients with primary traumatic proximal humerus shaft fracture treated with a straight or twisted helical PHILOS® plate were analyzed and compared. Among the 62 patients meeting the inclusion criteria between 2008 and 2018, 33 received a conventional straight plate, while 29 were treated with a helical plate. The primary endpoint was iatrogenic radial nerve damage immediately after surgery with a follow-up of at least 3 months. RESULTS: No case of radial nerve damage was reported in the helical group. In the control group, iatrogenic radial nerve damage occurred in two cases (6%), which was not statistically significant when comparing both groups (p = 0.18). CONCLUSION: Manually twisting long PHILOS® plates is a safe procedure to avoid radial nerve lesion in humerus shaft fractures. Even though the group size did not allow a statistically relevant difference, we underline that only the helical group showed no iatrogenic radial lesion. This technique deserves further attention. LEVEL OF EVIDENCE: Level 3, retrospective cohort study.

[Reconstruction of a fracture of the posterior acetabular wall with Pipkin fracture and lesion of the sciatic nerve after dorsal hip dislocation]. / Rekonstruktion einer Fraktur der hinteren Acetabulumwand mit Pipkin-Fraktur und Ischiadicusläsion nach dorsaler Hüftluxation.

A 50-year-old male suffered a crash landing while paragliding and sustained a posterior dislocation of the hip with a Pipkin fracture type 4 (fracture of the posterior acetabular wall and Pipkin fracture type 2) and a lesion of the sciatic nerve. After primary treatment in an external hospital, the patient was transferred to this hospital 4 days following the trauma. An operative stabilization of the acetabular fracture and the Pipkin fracture was performed using a trochanter flip osteotomy. Despite a large central defect of the femoral head it was decided to attempt a reconstruction. Following fixation of the Pipkin fragment an autologous bone graft harvested from the intertrochanteric region was used to fill the defect. Subsequently, a collagen matrix was applied onto the filled defect and a perineural adaptation of the sciatic nerve was performed.

Interleukin-6 contributes to initiation of neuronal regeneration program in the remote dorsal root ganglia neurons after sciatic nerve injury.

To assess the potential role of IL-6 in sciatic nerve injury-induced activation of a pro-regenerative state in remote dorsal root ganglia (DRG) neurons, we compared protein levels of SCG-10 and activated STAT3, as well as axon regeneration in IL-6 knockout (IL-6ko) mice and their wild-type (WT) counterparts. Unilateral sciatic nerve compression and transection upregulated SCG-10 protein levels and activated STAT3 in DRG neurons not only in lumbar but also in cervical segments of WT mice. A pro-regenerative state induced by prior sciatic nerve lesion in cervical DRG neurons of WT mice was also shown by testing for axon regeneration in crushed ulnar nerve. DRG neurons from IL-6ko mice also displayed bilaterally increased levels of SCG-10 and STAT3 in both lumbar and cervical segments after sciatic nerve lesions. However, levels of SCG-10 protein in lumbar and cervical DRG of IL-6ko mice were significantly lower than those of their WT counterparts. Sciatic nerve injury induced a lower level of SCG-10 in cervical DRG of IL-6ko than WT mice, and this correlates with significantly shorter regeneration of axons distal to the crushed ulnar nerve. These results suggest that IL-6 contributes, at the very least, to initiation of the neuronal regeneration program in remote DRG neurons after unilateral sciatic nerve injury.

Peripheral nerve injuries in the pediatric population: a review of the literature. Part I: traumatic nerve injuries.

OBJECTIVE: This article reviews the clinical results that can be obtained after repair of a traumatic peripheral nerve injury in the pediatric population. METHODS: A systematic review of the published literature has been made. RESULTS: Functional outcome after major nerve injuries is sometimes disappointing in adults. However, children have been reported to experience much better functional results after nerve repair than adults. Moreover, recovery generally is faster in children. The superior capacity of children's central nervous system to adapt to external or internal environmental changes (neural plasticity) and the shorter recovery distance from the axon repair site to the target muscle are claimed to be crucial determinants of their favorable outcomes. Moreover, even in the pediatric population, it has been demonstrated that functional results are better the younger the patient is, including better clinical results in those injured in early childhood (< 6 years old) than in those injured in adolescence. Other favorable prognostic factors include the type of nerve injury (with complete transections doing less well than crush injuries) and the timing of surgery (with better outcomes after early repairs). CONCLUSIONS: All efforts should be done to repair in a timely and adequate fashion traumatic peripheral nerve injuries in children, as the results are good.

5.3.5 Rule for examining the muscles of the upper limb.

The current technique taught for examining the muscles of the upper limb does not differentiate between the various causes of weakness in the arm, in particular peripheral nerve and nerve root lesions. The 5.3.5 rule describes examining the muscles in a specific order: 5 at the shoulder, 3 at the elbow and 5 at the wrist and hand. The examiner records the number of the weak muscles. They then consult the tables to determine the cause of the weakness. This rule enables the diagnosis of all peripheral nerve and nerve root problems (radiculopathy) that cause weakness in the arm. It does not require detailed knowledge of neuroanatomy. It does require the examiner to learn how to examine each muscle so that they do not miss weakness or 'detect' weakness when there is none.

The surgical anatomy of the dorsal scapular nerve: a triple-tendon transfer perspective.

BACKGROUND: Iatrogenic or traumatic injury to the spinal accessory nerve is a rare but debilitating injury. An effective treatment, known as the Eden-Lange modification triple-tendon transfer procedure, involves the transfer of the rhomboid major (RM), rhomboid minor (Rm), and levator scapulae (LS). Careful detachment of their insertions is necessary to avoid injury of the dorsal scapular nerve (DSN). This study evaluated the surgical anatomy and safety of the DSN relative to this procedure. METHODS: The study used 12 cadavers (22 shoulders). The RM, Rm, and LS were detached from their insertions, and the DSN was dissected. Measurements were taken to evaluate the anatomy of each relative to the triple-tendon transfer procedure. Additional measurements were taken to identify "danger zones" for DSN injury, regarding detachment of RM, Rm, and LS from their respective insertions. RESULTS: Measurements of the 22 shoulders included in the study showed wide variation in anatomy. The minimum distance between the scapula and the DSN at the vertebral scapular border was 0.7 cm, suggesting that care and precision are needed to perform this technique. The region where the DSN crosses the superior border of the Rm was shown to be the greatest "danger zone" of this technique, with a mean distance to the scapula of 1.61 ± 0.53 cm CONCLUSIONS: This study provides insight into the surgical anatomy of the DSN relative to a rare but successful procedure used to treat trapezius paralysis. The results of this study can inform the surgeon regarding potential anatomic considerations when performing the triple-tendon transfer.

Predictive value of metacarpophalangeal stabilization tests for simulated ulnar nerve lesion measured by a sensor glove.

STUDY DESIGN: A within-subject research design was used in this study. The difference of the range of motion (ROM) with and without ulnar nerve block was analyzed. INTRODUCTION: For the clinical evaluation of the functional effects of ulnar nerve palsy at the hand the relevance of clinical tests is in discussion. PURPOSE OF THE STUDY: The aim of the study was to evaluate the predictive value of 2 clinical tests for a simulated ulnar nerve lesion by motion analysis with a sensor glove. METHODS: In 28 healthy subjects, dynamic measurements of the finger joints were performed by a sensor glove with and without ulnar nerve block at the wrist. In the 0° metacarpophalangeal (MCP) stabilization test, the subjects were asked to stabilize the MCP joints actively in 0° while moving the interphalangeal joints, whereas at the 90° MCP stabilization test, the subjects stabilized the MCP joints actively in the 90° position. RESULTS: In the 0° MCP stabilization test, no remarkable changes of the ROM were found at the MCP joints; at the proximal interphalangeal joints 2-5, the ROM decreased with ulnar nerve block, significantly at the index, middle, and ring fingers (P < .05). In the 90° MCP stabilization test, the average ROM of the MCP joints 2-5 significantly increased with ulnar nerve block (P < .05), whereas at the PIP joints, the average ROM decreased (P < .05). DISCUSSION: The 90° MCP stabilization test had a high predictive value for the discrimination between healthy subjects and subjects with a simulated peripheral ulnar nerve lesion. CONCLUSIONS: The results could be relevant for the determination of the functional effect of ulnar nerve palsy and the quantification of clawing in hand rehabilitation. LEVEL OF EVIDENCE: II.

Quantification of weakness caused by distal median nerve lesion by dynamometry.

INTRODUCTION: In the assessment of hand and upper limb function, grip strength is of major importance. Use of the JAMAR dynamometer has been an accepted test of grip strength and routinely part of the physical examination. PURPOSE OF THE STUDY: The aim of this study was to determine by means of a median nerve block simulating a patient group if the measurement of different types of grip force can improve the quantification of impairment of the hand beyond the sole power grip measurements. METHODS: In 29 healthy volunteers, grip force measurement was done by the JAMAR dynamometer for power grip and by a pinch grip dynamometer for pincer grip, precision grip, pinch grip, and palmar abduction. At the power grip, the force of digit 2-5 was measured separately by a sensor glove. For each measurement, 3 trials were recorded subsequently. STUDY DESIGN: A within-subject research design was used in this prospective study. Each subject served as the control by preinjection measurements of grip and pinch strength. Subsequent measurements after median nerve block were used to examine within-subject change. RESULTS: In power grip, there was no significant reduction of maximum grip force with median nerve block compared with grip force without block. By measuring the finger forces by a sensor glove, a reduction of force at the individual fingers was found compared with the setting with no block, although significant only at the middle finger (P < .017). With median nerve block, average grip force decreased significantly 20% in pincer grip (P < .021), 29.5% in pinch grip (P < .002), 39.5% in precision grip (P < .001), and 70.7% in palmar abduction (P < .013). CONCLUSIONS: These experiments suggest a minor role of the measurement of the power grip force in the diagnostics of distal median nerve block with the dynamometer, which could not be substantially improved by the digit forces and the force distribution of the individual fingers. The assessment of other grip forms, such as pincer grasp, precision grip, pinch grip, and especially palmar abduction, leads to a relevant improvement in the diagnostics of distal median nerve lesion. LEVEL OF EVIDENCE: II.