Ulnar Nerve Block Research Articles

(371) Pain over the dorsum of third metacarpophalangeal joint: which nerve to block, radial or ulnar?

The distribution of radial and ulnar nerve on the dorsum of hand seems pretty demarcated in textbooks. However overlap or crossover of nerve distribution might happen especially after injury or surgery. In this case report, a 42 year old male suffered right third metacarpophalageal (MCP) joint fracture with a traumatic degloving type laceration over the dorsal aspect of the right hand over a year ago. He had open reduction and internal fixation of right middle metacarpal fracture and wrist external fixation surgery on the same day of injury. Six months after surgery, patient was referred to our pain clinic for persistent pain over the right third MCP joint which completely resolved after scar injection. However, the pain relief only lasted for couple days. Patient subsequently had right superficial radial nerve block which only provided 20-25% instant pain relief. Scar injection with Botox provided complete pain relief which unfortunately only lasted for about a month. Patient subsequently went through a second hand surgery for excision of an osteophyte at the radial side of the right third MCP joint. Also a radial sensory neuroma was identified during the surgery which was buried into distal right radius. However three months later, patient returned to the clinic with persistent pain over the same location--dorsal third MCP joint. Diagnostic nerve block of right dorsal antebrachial cutaneous nerve and right common radial nerve failed to relieve the pain. Eventually dorsal branch of the ulnar nerve was identified (as a small fascicular bundle separating from the distal ulnar nerve then passing dorsally around the ulna deep to the flexor carpi ulnaris) and specifically blocked with a small volume of local anesthetic resulting in complete resolution of pain. Lack of ulnar nerve block was confirmed by spared sensation over ventral hand.

Concurrent proximal suspensory desmopathy and injury of the proximal aspect of the accessory ligament of the deep digital flexor tendon in forelimbs or hindlimbs in 19 horses

SummaryClinical features of proximal suspensory desmopathy (PSD) and concurrent injury of the proximal aspect of the accessory ligament of the deep digital flexor tendon (ALDDFT) have not been documented. The objectives were to describe clinical signs and diagnosis. This was a retrospective study. Patient details, lame limb(s), response to diagnostic analgesia, and radiographic and ultrasonographic findings were recorded. PSD and injury of the proximal aspect of the ALDDFT were identified in 19 horses, 14 with forelimb lameness (unilateral 5, bilateral 9) and 5 with hindlimb lameness (unilateral 2, bilateral 3). Localising clinical signs were seen in 7/31 lame limbs (subtle thickening in the region of the ALDDFT [n = 3], pain on palpation of the body of the suspensory ligament (SL) [n = 6], heat in the proximal metacarpal or metatarsal region [n = 2]). Forelimb lameness was abolished by perineural analgesia of the palmar metacarpal (subcarpal) nerves in 17/23 limbs. In the remaining limbs intra‐articular analgesia of the middle carpal joint (n = 2) or an ulnar nerve block (n = 4) were required to eliminate the lameness. Hindlimb lameness was abolished by perineural analgesia of the deep branch of the lateral plantar nerve (n = 2) or local infiltration of the proximal plantar aspect of the metatarsus (n = 3); a tibial nerve block resolved lameness in the remaining 3 limbs. Lesions of the SL and of the ALDDFT were characterised ultrasonographically by enlargement, heterogeneous echogenicity and loss of long linear echoes in longitudinal images. In 3 horses adhesions between the ALDDFT and the SL were identified post mortem. Close apposition of these structures seen ultrasonographically may indicate adhesion formation. It was concluded that the clinical features of PSD and concurrent injury of the ALDDFT are similar to those for PSD alone, highlighting the need for comprehensive and systematic ultrasonographic assessment.

Concurrent Proximal Suspensory Desmopathy And Injury of the Proximal Aspect of the Accessory Ligament of the Deep Digital Flexor Tendon in Forelimbs and Hindlimbs

Reasons for performing studyThere are no reports of proximal suspensory desmopathy (PSD) and concurrent injuries of the proximal aspect of the accessory ligament of the deep digital flexor tendon (ALDDFT).ObjectivesTo describe clinical features, response to local analgesia and ultrasonographic features.Study designRetrospective study.MethodsReview of case records, January 2009–2014.ResultsThere were 8 horses with forelimb lameness, 4 unilateral and 4 bilateral (2 with bilateral injuries of the suspensory ligament [SL] and ALDDFT and 2 with PSD and injury of the ALDDFT in one limb and injury of the ALDDFT alone in the other). One horse had pain on palpation of the proximal aspect of the ALDDFT. Lameness was abolished by palmar metacarpal (subcarpal) nerve blocks in 10/12 limbs; in 2 limbs an ulnar nerve block was required to abolish lameness. There were 5 horses with bilateral hindlimb lameness; concurrent desmopathy of the ALDDFT and PSD was identified in one horse. In the other 4 horses there was a history of bilateral PSD which had undergone treatment. Recurrent lameness was associated with unilateral (n = 3) or bilateral (n = 1) PSD and desmopathy of the ALDDFT. In 2 horses there was soft tissue swelling in the proximomedial aspect of the metatarsus in the region of the ALDDFT. Lameness was abolished by local infiltration of mepivacaine in the proximoplantar aspect of the metatarsus in 3 limbs; in one limb a tibial nerve block was required to eliminate lameness. In all horses lesions were characterised ultrasonographically by enlargement of both the ALDDFT and the proximal aspect of the SL and a diffuse decrease in echogenicity. There was echogenic material between the SL and ALDDFT in 5 limbs.ConclusionsAll soft tissue structures in the proximal aspect of the metacarpus/metatarsus should be evaluated ultrasonographically if pain is localised to this area.Ethical animal research: The study was approved by the Ethical Review Committee of the Animal Health Trust and there was informed owner consent. Sources of funding: None. Competing interests: None.

Can we gain an advantage by combining distal median, radial and ulnar nerve blocks with supraclavicular block? A randomized controlled study.

The aim of this study was to compare the combined ultrasound-guided supraclavicular brachial plexus block (SCB) and distal median, radial, and ulnar nerve blocks, with the supraclavicular block alone. Sixty-two patients undergoing upper extremity surgery were randomized to supraclavicular only (Group S, n=31) or supraclavicular+distal (Group SD, n=31) group. Patients in Group S received 32mL of 1.5% lidocaine+epinephrine 5µg/mL, while those in Group SD received 20mL of 1.5% lidocaine+epinephrine 5µg/mL followed by distal median, radial, and ulnar nerve blocks using equal volumes of 2% lidocaine+0.5% levobupivacaine (4mL/nerve). Sensory and motor blocks of the ulnar, median, radial and musculocutaneous nerves were assessed every 5min starting at the 10th minute. The imaging, needling and performance times were recorded. Also, the onset and anesthesia-related times, need for analgesic and first analgesic times, were noted. In Group SD, the anesthesia onset [15 (10-25) vs. 20 (15-30) min, p<0.001] and anesthesia related times [16.6 (10.7-28.2) vs. 22 (15.9-33.7) min, p<0.001] were significantly shorter than those of Group S. Additionally, the analgesic requirement was lower in Group SD (56.7 vs. 88.5%, p=0.009), while among the patients who required analgesic, the first analgesic time was longer in Group SD in comparison to Group S [625 (347-1764) vs. 315 (233-746) min p<0.001]. The addition of distal median, radial, and ulnar nerve blocks to SCB shortens anesthesia-related time and anesthesia onset time when compared with a SCB alone.

SAT0197 Ultrasound Guided Musculoskeletal Procedures under Peripheral Nerve Block: A Pilot Controlled Study in Rheumatic Patients

BackgroundMusculoskeletal Ultrasound (US) is a valuable tool in the diagnosis and monitoring of rheumatic diseases. Invasive musculoskeletal procedures under US guidance improve technical accuracy and efficacy. However, patients complain of...

A cadaveric study comparing the three approaches for ulnar nerve block at wrist.

Background:Ulnar nerve blockade as a component of wrist block is a promising technique for adequate anesthesia and analgesia for different surgeries of the hand. Due to anatomical variations in the location of ulnar nerve under the flexor carpi ulnaris (FCU) a technique with good results and minimal complications are required.Aim:The aim of the following study is to compare the three techniques (volar, transtendinous volar [TTV] and ulnar) for ulnar nerve block at the wrist in human cadaveric wrists.Materials and Methods:Our study was conducted using 40 cadaver wrists. After inserting standard hypodermic needles by three techniques for ulnar nerve blockade at the wrist, a detailed dissection of FCU was done. The mean distance from the tip of the needle to ulnar artery/nerve and number of instances in which the ulnar artery/nerve pierced were observed.Results:Inter-group statistical significance was observed in measurement of the mean distance (mm) from the tip of the needle to the ulnar artery (volar [0.92 ± 0.11], TTV [3.96 ± 0.14] and ulnar [7.14 ± 0.08] approaches) and ulnar nerve (volar/TTV/ulnar approaches were 0.71 ± 0.12/3.61 ± 0.10/6.31 ± 0.49, respectively) (P = 0.001). Inadvertent intra-arterial/intraneural injections was seen with volar approach in 14 (35%) and 16 (40%) of the cadaveric wrists respectively, statistically significant with transtendinous and ulnar techniques of ulnar nerve block.Conclusion:TTV approach could be a better technique of choice for ulnar nerve blockade at the wrist because of its ease to practice, safer profile and minimum chances of inadvertent intra-arterial/intraneural injection with adequate anesthesia/analgesia.

Comparison of the Volar and Medial Approach in Peripheral Block of Ulnar Nerve at the Wrist – A Cadaveric Study

Two standard approaches are described to block the ulnar nerve at wrist. These include a) the traditional Volar approach where the needle is inserted lateral to tendon of flexor carpi ulnaris (FCU) b) Medial approach where the needle is inserted posterior to the tendon of FCU. Caution must be exercised to avoid puncture of the ulnar artery and/or intraneural injection of the ulnar nerve in both the approaches. This study compares the volar and medial approach to the peripheral block of ulnar nerve at the wrist. The objective was two fold: a) to analyze the position of the ulnar nerve and the ulnar artery in relation to the Flexor Carpi Ulnaris tendon b) to assess the risk of injury to ulnar artery in both the volar and medial approach. Twelve cadaveric upper limbs were used and both approaches compared by an observational study. Two 18 G needles were inserted up to a depth of 7 mm using the standard volar and medial approach. The pattern of arrangement and positions of the ulnar artery and nerve in relation to FCU tendon were observed. The distance between the tip of needle and its proximity to the ulnar artery, and risk of injury were determined. Statistical analysis was done using SPSS for Windows, Version 16.0. Chicago, SPSS Inc. Three patterns of arrangement and position of the ulnar nerve and artery were observed. Puncture of ulnar artery was seen in 50% of cases in the volar approach as compared to no injury at all in the medial approach. The ulnar artery is highly liable to injury during the volar approach in type I and II and safe only in type III arrangement of ulnar artery. The medial approach showed no injury to the ulnar artery or nerve at a penetration depth of 7mm. The medial approach is safer compared to volar approach for peripheral block of ulnar nerve at wrist.

Dexmedetomidine as an Adjuvant to Ropivacaine Prolongs Peripheral Nerve Block

Background. Dexmedetomidine is an a-2-receptor agonist which might be used as an additive to local anaesthetics for various regional anaesthetic techniques. We therefore designed this prospective, double-blinded, controlled volunteer study to investigate the effects of dexmedetomidine as an adjuvant to ropivacaine on peripheral nerve block. Methods. Ultrasound-guided ulnar nerve block (UNB) was performed in 36 volunteers with either 3 ml ropivacaine 0.75% (R), 3 ml ropivacaine 0.75% plus 20 mg dexmedetomidine (RpD), or 3 ml ropivacaine 0.75% plus systemic 20 mg dexmedetomidine (RsD). UNBrelated sensory and motor scores were evaluated. Results. Sensory onset time of UNB was not different between the study groups, whereas motor onset time was significantly faster in Group RpD when compared with the other study groups [mean (SD)] [21 (15) vs 43 (25) min in Group RsD and 47 (36) min in Group R, P,0.05 Group RpD vs other groups]. The duration of sensory block was 350 (54) min in Group R, 555 (118) min in Group RpD, and 395 (40) min in Group RsD (P,0.01 Group RpD vs other groups, P,0.05 Group RsD vs Group R). Motor block duration was similar to the duration of sensory block. Conclusions. A profound prolongation of UNB of � 60% was detected with perineural dexmedetomidine when added to 0.75% ropivacaine. The systemic administration of 20 mg dexmedetomidine resulted in a prolongation of � 10% during UNB with 0.75% ropivacaine. Eudra-CT No.: 2012-000030-19.

Dexmedetomidine as an adjuvant to ropivacaine prolongs peripheral nerve block: a volunteer study

Dexmedetomidine is an α-2-receptor agonist which might be used as an additive to local anaesthetics for various regional anaesthetic techniques. We therefore designed this prospective, double-blinded, controlled volunteer study to investigate the effects of dexmedetomidine as an adjuvant to ropivacaine on peripheral nerve block. Ultrasound-guided ulnar nerve block (UNB) was performed in 36 volunteers with either 3 ml ropivacaine 0.75% (R), 3 ml ropivacaine 0.75% plus 20 µg dexmedetomidine (RpD), or 3 ml ropivacaine 0.75% plus systemic 20 µg dexmedetomidine (RsD). UNB-related sensory and motor scores were evaluated. Sensory onset time of UNB was not different between the study groups, whereas motor onset time was significantly faster in Group RpD when compared with the other study groups [mean (sd)] [21 (15) vs 43 (25) min in Group RsD and 47 (36) min in Group R, P<0.05 Group RpD vs other groups]. The duration of sensory block was 350 (54) min in Group R, 555 (118) min in Group RpD, and 395 (40) min in Group RsD (P<0.01 Group RpD vs other groups, P<0.05 Group RsD vs Group R). Motor block duration was similar to the duration of sensory block. A profound prolongation of UNB of ∼60% was detected with perineural dexmedetomidine when added to 0.75% ropivacaine. The systemic administration of 20 µg dexmedetomidine resulted in a prolongation of ∼10% during UNB with 0.75% ropivacaine. Eudra-CT No.: 2012-000030-19.

Concomitant infraclavicular plus distal median, radial, and ulnar nerve blockade accelerates upper extremity anaesthesia and improves block consistency compared with infraclavicular block alone

This prospective, randomized, observer-blinded study tested the hypothesis that a combined ultrasound-guided block of the infraclavicular brachial plexus plus distal median, radial, and ulnar nerves would accelerate upper extremity anaesthesia compared with infraclavicular block alone. Elective wrist and hand surgery patients were randomly assigned to receive 42 ml infraclavicular lidocaine 1.5% with epinephrine 1/200,000 ('infraclavicular only'; n=30) or 30 ml lidocaine 1.5% with epinephrine 1/200,000 followed by a distal median, radial, and ulnar nerve block using 12 ml 50:50 lidocaine 2%+ropivacaine 0.75% ('combined'; n=31). A blinded observer assessed pinprick sensory and motor block in the four distal nerve territories at 10 and 15 min (each nerve/parameter: no block, 3, to complete block, 0). Total aggregate block score (sensory+motor) was reduced in the combined group at 15 min [mean (95% confidence interval)=6.7 (5.3-8.1) vs. 9.9 (7.9-11.9), mean difference (95% confidence interval)=3.2 (0.81-5.6), P=0.01], and corresponded to an estimated onset effect time benefit of 6 min (∼40% treatment effect). The combined group also demonstrated reduced variance about the mean (sd=3.7 vs. 5.4, P=0.046). Mean (sd) total block score (sensory+motor) was significantly reduced at 15 min in the combined group for each individual nerve [median, radial, ulnar, respectively: 1.4 (1.1) vs. 2.4 (1.5), P=0.005; 1.2 (1.1) vs. 2.0 (1.5), P=0.03; 1.6 (1.3) vs. 2.5 (1.6), P=0.03]. At an approximately equivalent total local anaesthetic dose, a combined infraclavicular block plus distal median, radial, and ulnar nerve blockade accelerates anaesthesia onset time and improves block consistency compared with an infraclavicular block alone. ANZCTR: ACTRN12610000155099. https://www.anzctr.org.au/registry/trial_review.aspx?ID=335162.

Spread of local anesthetic during an ultrasound-guided interscalene block: does the injection site influence diffusion?

During interscalene block (ISB) placement, ultrasound guidance (USG) enables the practitioner to measure the spread of local anesthetic around the nerve trunks or roots, and to adjust the needle position in order to optimize diffusion. Moreover, USG helps determine the best injection level, i.e. the point from which diffusion gives the most complete brachial plexus block. The aim of this study was to compare C5 and C6 level injections and to determine which level allows the best diffusion. Sixty randomized patients scheduled for shoulder surgery were divided into two groups. In group C5, injection was directed toward C5 while in group C6, the C6 nerve root was targeted. Block performance time was recorded. The onset of motor and sensory block of each nerve distribution was evaluated every 10 min over a 30-min period. The average time taken to perform a nerve block was 6.2+2.6 min in Group C6 and 6.0+2.1 min in Group C5 (NS). At 30 min, the number of patients with a satisfactory musculocutaneous and axillary nerve block was not notably greater in either group. By contrast, a significantly higher success rate was observed for other nerves in the C6 group as compared to the C5 group: ulnar nerve block: 93% vs. 19%, radial nerve block: 96% vs. 28%, median nerve block: 96%, vs. 69%. During USG ISB placement, injection below the C6 level provided the same efficiency in analgesia after shoulder surgery as an injection cranial to the C5 nerve root but a greater success rate of anesthesia in all distal nerve areas. This technique could be very interesting for trauma cases as an alternative to a supraclavicular block and offers a high success rate and is simple to perform, potentially promoting wide use and quicker learning for beginners.

Nerve Blocks at the Wrist for Painful Injections of the Palm

Injections into the palmar hand for trigger finger, palmar flexor tenosynovitis, and Dupuytren contracture can be very painful. This randomized, controlled study evaluated nerve block anesthesia at the wrist for prevention of procedural pain associated with painful injection of the palmar hand. Forty-seven corticosteroid injections for trigger fingers in 19 individuals were randomized to (1) anesthesia consisting of median and ulnar nerve block with 1% lidocaine anesthesia followed by standard injection or (2) standard injection alone using the 1-needle 2-syringe technique consisting of transthecal dilation of the synovial sheath with 0.5 mL 1% lidocaine with a mechanical syringe, the reciprocating procedure device, followed by injection with 20 mg triamcinolone acetonide. Baseline pain, needle insertion/sheath dilation pain, corticosteroid injection pain, resolution of trigger finger, and pain at outcome (2 weeks) were determined. Standard injection for trigger finger was associated with significant pain in 100% of subjects. Nerve blocks at the wrist provided effective anesthesia, resulting in a 56% reduction in injection pain compared with direct injection (P < 0.01). There was 100% resolution of trigger finger in both treatment groups. Pain at the 2-week outcome, reduction in pain from baseline, responders, and nonresponders were not statistically different (P > 0.3 for all). Eighty-eight percent of subjects preferred nerve block anesthesia to direct injection (P < 0.0001). Nerve block anesthesia at the wrist before palmar injection is preferred by patients and is highly effective in preventing pain associated with injection of the palmar hand for trigger finger and other painful hand procedures.

P5.5 Partial conduction block of ulnar nerve at the wrist

P5.5 Partial conduction block of ulnar nerve at the wrist

A clinical study of modified subclavicular brachial plexus block with localized puncture at the apex of the axilla

Objective To study the feasibility of subclavicular brachial plexus block with localized puncture at the apex of the axilla.Methods 520 adult patients who underwent upper limb emergency surgery were randomly assigned to receive subclavicular brachial plexus block with localized puncture at the apex of the axilla ( experimental group) and block anesthesia with intraclavicular route ( control group).Patients in both groups received 0.375% ropivacaine, volume (40.0± 2.7)ml.During the 30 minutes after the blockade, the onset and effect of motor and sensory block, the sensory block effect of each nerve branches and integrated effect of nerve block were recorded.The VAS score and acesodyne duration with tourniquet were compared between the two groups at 2, 4, 6 and 8 hours after the drug had been used for 30 minutes.Results Within 30 minutes after the drug was delivered, the onset of motor and sensory block in the experimental group was evidently shorter than that in the control group, while the duration of motor and sensory block was evidently longer ( P ＜ 0.01).There were no statistically significant differences in motor and sensory block score, median nerve block effect and ulnar nerve block effect between the two groups.The musculocutaneous nerve and radial nerve block effects in the experimental group were better than those in the control group ( P ＜ 0.05).After the drug had been used for 30 minutes, VAS score of the experimental group at each point time was significantly lower than that of the oontrol group ( P ＜0.01).The analgesia duration of tourniquet in the experimental group was significantly longer than that of the control group ( P ＜ 0.01 ).Conclusion The modified subclavicular brachial plexus block with localized puncture at the apex of the axilla can provide perfect blockade, satisfactory anesthetic effect and higher safety in upper limb surgery. Key words: Anesthesia; Brachial plexus; Clavicle; Neuromuscular blockade

Estimation and Pharmacodynamic Consequences of the Minimum Effective Anesthetic Volumes for Median and Ulnar Nerve Blocks

Nerve stimulation and ultrasound guidance are the most popular techniques for peripheral nerve blocks. However, the minimum effective anesthetic volume (MEAV) in selected nerves for both techniques and the consequences of decreasing the local anesthetic volume on the pharmacodynamic characteristics of nerve block remain unstudied. We designed a randomized, double-blind controlled comparison between neurostimulation and ultrasound guidance to estimate the MEAV of 1.5% mepivacaine and pharmacodynamics in median and ulnar nerve blocks. Patients scheduled for carpal tunnel release were randomized to ultrasound guidance (UG) or neurostimulation (NS) groups. A step-up/step-down study model (Dixon method) was used to determine the MEAV with nonprobability sequential dosing based on the outcome of the previous patient. The starting dose of 1.5% mepivacaine was 13 and 11 mL for median and ulnar nerves at the humeral canal. Block success/failure resulted in a decrease/increase of 2 mL. A blinded physician assessed sensory blockade at 2-minute intervals for 20 minutes. Block onset time and duration were noted. The MEAV50 (SD) of the median nerve was lower in the UG group 2 (0.1) mL (95% confidence interval [CI] = [1, 96] to [2, 04]) than in the NS group 4 (3.8) mL (95% CI = [2, 4] to [5, 6]) (P = 0.017). There was no difference for the ulnar nerve between UG group 2 (0.1) mL (95% CI = [1, 96] to [2, 04]) and NS group 2.4 (0.6) mL (95% CI = [2, 1] to [2, 7]). The duration of sensory blockade was significantly correlated to local anesthetic volume, but onset time was not modified. Ultrasound guidance selectively provided a 50% reduction in the MEAV of mepivacaine 1.5% for median nerve sensory blockade in comparison with neurostimulation. Decreasing the local anesthetic volume can decrease sensory block duration but not onset time.

Which anatomical region determines a positive flexion test of the distal aspect of a forelimb in a nonlame horse?

The flexion test is used routinely as part of lameness and prepurchase examinations. However, little is known about the mechanisms that cause a positive response to a flexion test. To determine which anatomical regions play a role in a positive outcome of a flexion test of the distal aspect of a forelimb in a nonlame horse. Eight clinically sound Dutch Warmblood horses were subjected to a standardised flexion test (force 250 N, time 60 s) inducing a consistent lameness. To discriminate between different areas of the distal aspect of a forelimb, effects of various nerve blocks on the outcome of the flexion test were investigated. Low palmar digital, palmar at the abaxial aspects of the base of the proximal sesamoids, high palmar, ulnar and low 4-point nerve blocks were performed. Flexion test induced lameness was scored before and after each nerve block in separate sessions. The low palmar digital nerve blocks and nerve blocks of the palmar nerves at the abaxial aspect of the base of the proximal sesamoid bones had no significant effect on the flexion test induced lameness score. The ulnar, high palmar and, most dramatically, the low 4-point nerve blocks all caused a significant (P<0.05) reduction in the flexion test induced lameness score. Anatomical structures (soft tissue nor synovial structures) located distal to the metacarpophalangeal joint appear to contribute only minimally to the outcome of a positive flexion test of the distal aspect of a forelimb in a clinically nonlame horse. The structures in the region of, and including, the metacarpophalangeal joint appear to contribute most to a positive flexion test of the distal aspect of a forelimb in a nonlame horse. The flexion test of the distal aspect of a forelimb may be sensitive for investigating the metacarpophalangeal joint region in horses free from lameness, but may be less relevant for structures distal to this region.

Ultrasound‐guided Ulnar Nerve Block in the Management of Digital Abscess and Hand Cellulitis

Ultrasound‐guided Ulnar Nerve Block in the Management of Digital Abscess and Hand Cellulitis

Tendinitis of the proximal aspect of the superficial digital flexor tendon in horses: 12 cases (2000–2006)

To determine clinical signs, ultrasonographic findings, and outcome of horses with tendinitis of the proximal portion of the superficial digital flexor tendon (SDFT; group A horses) and to compare signalment, horse use, and outcome in these horses with that of horses with tendinitis of the midmetacarpal region of the SDFT (group B horses). Retrospective case series. 12 group A horses and 22 group B horses. Medical records were reviewed for signalment, horse use, and outcome information; data for group A horses also included severity of lameness, diagnostic results, and treatment. Most group A horses were aged (mean, 18 years; median, 17 years; range, 11 to 23 years) Quarter Horses (9/12 horses) and had a grade 3 or 4 (on a scale from 1 to 5) forelimb lameness. Most group A horses (8/12 horses) had positive reactions to carpal flexion and were (9/12 horses) sound following ulnar nerve blocks. Ultrasonographic evaluation revealed hypoechoic SDFT lesions (median echogenicity score, 3/4; median fiber alignment score, 3/3; and mean length, 9.75 cm). Group A horses were significantly older and had a poorer outcome for return to previous use (2/12 horses), compared with group B horses (median age, 5 years; 10/22 horses returned to previous use). Thirteen of 22 group B horses were Thoroughbreds. Tendinitis of the proximal portion of the SDFT was a cause of lameness in aged performance horses; prognosis for return to previous use was poor.

Ultrasound- or Nerve Stimulation-Guided Wrist Blocks for Carpal Tunnel Release: A Randomized Prospective Comparative Study

We hypothesized that ultrasound-guided wrist blocks may be faster to perform, and may increase success rate, compared with nerve stimulation-guided wrist blocks. Sixty patients undergoing ambulatory endoscopic carpal tunnel release were randomly allocated to receive median and ulnar nerve blocks using either sensory-motor nerve stimulation (n = 30) or ultrasound guidance (n = 30). Four mL of mepivacaine 1.5% was injected around each nerve. Performance time and onset time of complete sensory block were assessed. Median time to perform both median (ultrasound, 55 [48-60] vs. nerve stimulation, 100 [65-150] seconds, P = .002) and ulnar (ultrasound, 57 [50-70] vs. nerve stimulation, 80 [60-105] seconds, P = .02) nerve blocks were significantly shorter in the ultrasound group. Onset time of complete sensory block in the median (ultrasound, 370 [278-459] vs. nerve stimulation, 254 [230-300] seconds, P = .02) and ulnar (ultrasound, 367 [296-420] vs. nerve stimulation, 241 [210-300] seconds, P = .01) nerve areas were shorter in the nerve stimulation group. The success rate was 93% in both groups. This randomized prospective study demonstrates that ultrasound-guided wrist nerve blocks are as efficient as those performed with nerve stimulation.

Sonoanatomy Of The Ulnar Nerve In The Distal Forearm

Sonoanatomy Of The Ulnar Nerve In The Distal Forearm