Ultrasound-guided first annular pulley injection for trigger finger

Is arthritis an associated risk factor for trigger finger occurrence after carpal tunnel release? A nationwide, population-based study in Korea

PURPOSE

We hypothesized that increased friction between the flexor tendon and surrounding structures due to hand arthritis is an important risk factor for trigger finger (TF) after carpal tunnel release (CTR). Therefore, we compared TF development according to the presence or absence of arthritis in carpal tunnel syndrome (CTS) patients treated with CTR.

METHODS

This retrospective study was based on data collected from the National Health Insurance Service-National Sample Cohort (NHIS-NSC) in the Republic of Korea between January 1, 2002, and December 31, 2015. Patients diagnosed with TF between one month and one year after the CTR date or with a history of surgery were included in the study. During subsequent follow-up, the patients were divided into subgroups of those (1) with TF and (2) without TF. Sex, age, arthritis, and TF-related comorbidities were compared between the subgroups.

RESULTS

The subgroup with TF had a higher proportion of women (9.43% vs 90.57%), the highest age range between 50 and 59 years, more cases of arthritis (32.55% vs 16.79%), and a higher proportion of patients with hypothyroidism (10.85% vs 4.60%) than the group without TF. The association between arthritis and TF after CTR was examined using a multivariate logistic regression model, showing arthritis to be a significant risk factor for TF after CTR (odds ratio, 1.35; P = 0.049).

CONCLUSIONS

We identified arthritis as an important risk factor for the development of TF after CTR.

Responsiveness of PROMIS Instruments for Trigger Digit After Corticosteroid Injection or A1 Pulley Release

PURPOSE

The purpose of the study was to determine if the patient-reported outcomes measurement information system (PROMIS) is sufficiently sensitive to detect improvement after 2 common treatments of trigger finger: corticosteroid injection or A1 pulley release.

METHODS

This retrospective cohort study included 72 patients in the injection group and 51 in the A1 pulley release group. PROMIS physical function (PF), pain interference (PI), and upper extremity (UE) scores were collected at baseline and 6 weeks after injection for the injection group and at baseline, and 1 week, 6 weeks, and 3 months after surgery for A1 pulley release patients. Descriptive statistics and paired t tests were used to compare PROMIS scores within each cohort. Standardized response means (SRMs) were calculated for each PROMIS domain to gauge instrument responsiveness.

RESULTS

Average age was 62 years, 65% were female patients, and 86% were White for the steroid injection cohort, compared to 60 years, 71%, and 88%, respectively, for the A1 pulley release cohort. For the steroid injection group, mean PROMIS PI scores (-4.0 points; SRM = -0.6) and PROMIS UE scores (+3.3 points; SRM = 0.5) improved significantly at 6 weeks after injection compared to baseline. Meanwhile, A1 pulley release patients improved significantly in mean PI scores (-3.7 points; SRM = -0.5) and in UE scores (+4.9 points; SRM = 0.7) at 3 months after surgery compared to baseline.

CONCLUSIONS

Clinical improvements after trigger digit treatments are reflected in improved PROMIS PI and UE scores that reach previously accepted minimum clinically important difference values for hand patients. PROMIS PI and UE also are more responsive than PROMIS PF in capturing improvement for trigger digit treatments.

CLINICAL RELEVANCE

As health care payers continue to emphasize patient-reported outcomes to determine treatment value and set reimbursement rates, this study helps establish that clinical improvement after trigger digit treatments are reflected in PROMIS PI and UE domains by reaching previously established minimum clinically important difference values for hand patients.

Diagnostic and Interventional US of the Wrist and Hand: Quadrant-based Approach

Diagnostic and interventional US of the wrist and hand can be challenging due to the small size and superficial location of structures and various disorders that need to be considered. A quadrant-based approach (volar, ulnar, dorsal, and radial) provides a rational method for performing a focused examination and joint positioning during both diagnostic imaging and intervention. Volar wrist disorders primarily involve the median nerve and the digital flexor system comprised of the flexor tendons and pulleys. The ulnar nerve and extensor carpi ulnaris tendon are chiefly responsible for ulnar-sided wrist pain. The differential diagnosis for dorsal-sided symptoms typically involves the extensor tendon compartments and includes distal intersection syndrome, extensor pollicis longus tear, and digital extensor apparatus injury. The soft-tissue ganglion is the most common abnormality in the dorsal wrist, typically associated with wrist ligaments or joint capsule. Radial-sided pain may be secondary to de Quervain tenosynovitis and must be differentiated from the more proximal intersection syndrome. US is an important tool for assessing the ulnar collateral ligament of the first metacarpophalangeal joint of the thumb and differentiating between displaced and nondisplaced tears, thereby influencing management. Despite the complexity of the anatomy and potential pathologic features within the wrist, a focused quadrant-based examination can permit the sonologist to focus on the structures of relevance. In conjunction with a systematic approach, this can aid in precise and efficient diagnostic scanning and intervention of the wrist and hand. ©RSNA, 2023 Supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

Ultrasound guided versus blinded injection in trigger finger treatment: a prospective controlled study

BACKGROUND

Trigger finger is a common disease with a lifetime prevalence of 2%. One of the frequently preferred non-surgical treatments is blinded injection around the A1 pulley. This study aims to compare the clinical results of ultrasound-guided and blinded corticosteroid injection in the trigger finger.

METHODS

In this prospective clinical study, 66 patients who had persistent symptoms of a single trigger finger were included. Patients with similar baseline characteristics such as age, gender, triggering period, and comorbidities were randomized. 34 patients had ultrasound-guided (UG), and 32 had blinded injections (BG). QDASH, VAS, time to return to work, and complications were compared between the groups.

RESULTS

The mean age was 52,66 (29-73) years. There were 18 male and 48 female patients. In the UG, the triggering resolved faster, returning to work was earlier, and the medication period was shorter (p < 0.05). A total of 17 patients who had diabetes mellitus received re-injections, 11 of which were in BG and 6 in UG (p < 0.05). Although statistically significantly lower scores were obtained in UG at the 1st and 4th weeks in the QDASH and VAS scores (p < 0.05), at the 12th and 24 weeks, there was no significant difference (p > 0.05).

CONCLUSION

Using ultrasound guidance for corticosteroid injections is more effective for treating trigger fingers than the blinded method, leading to better results and a faster return to work in the early stages of treatment.

Musculoskeletal steroid injections in pregnancy: a review

Pregnant women experience a wide range of musculoskeletal pain disorders, which include general ailments occurring during pregnancy, exacerbation of pre-existing conditions, or pregnancy-specific pain/inflammatory conditions. There are significant concerns and knowledge gaps surrounding the safety, dosage, and potential long-term effects of several drugs used during pregnancy. Our article reviews the use of focal steroid injections during pregnancy. A mixture of case studies, meta-analyses, and randomised controlled trials have shown at least there is no adverse side effect to the mother or baby from maternal use of non-systemic injection during pregnancy and a significant improvement in symptoms of pain or paraesthesia can be achieved in patients that do not respond to more conservative measures. As with all patients, the use of steroid injection should be judged on a case-by-case basis to ensure that it is the most appropriate treatment choice. However, being pregnant should not be considered a contraindication to a single dose of non-systemic steroid administration, as these women can achieve significant symptomatic relief that reduces reliance on systemic medication and can significantly improve their quality of life.

Ultrasound-guided needle release of A1 pulley combined with corticosteroid injection is more effective than ultrasound-guided needle release alone in the treatment of trigger finger

BACKGROUND

The purpose of the present study was to evaluate the clinical effectiveness of ultrasonography-guided needle release of A1 pulley combined with corticosteroid injection by comparing it with ultrasound-guided needle release of the A1 pulley alone.

METHODS

A total of 49 patients (55 fingers, thumb) with trigger fingers were included in this retrospective study. Twenty-seven fingers were treated with ultrasound-guided needle release of the A1 pulley alone (monotherapy group), and 28 fingers were treated with needle release of the A1 pulley combined with corticosteroid injection (combination group). Visual analog scale (VAS), Froimson scale, postoperative recurrence rate, and thickness of A1 pulley at baseline, Week-2, Week-12, and Month-6 were recorded.

RESULTS

Higher clinical cure rates were observed in the combination group at Week-2 after treatment among patients with the Froimson scale Grade III and IV (p < 0.05). Among Froimson scale Grade IV patients, the combination group had a significantly thinner thickness of A1 pulley and better articular pain relief at Week-2 (all p < 0.05). No significant differences were found in the clinical cure rate, the thickness of the A1 pulley, articular pain relief, and recurrence rate between the two groups at Week-12 and Month-6 (all p > 0.05).

CONCLUSIONS

Ultrasonography-guided needle release of A1 pulley plus corticosteroid injection was superior to ultrasonography-guided A1 pulley needle release alone during early-stage treatment of severe patients with trigger fingers. Moreover, ultrasonography-guided A1 pulley needle release combined with corticosteroid injection narrows the thickness of the A1 pulley. It is necessary to carry out preoperative evaluation and individualized treatment for patients of various severities.

Corticosteroid Injection for the Treatment of Trigger Finger: A Meta-Analysis of Randomised Control Trials

Background: The purpose of this meta-analysis is to provide an evidence-based overview of the effectiveness of corticosteroid injection for the treatment of stenosing tenosynovitis (trigger digits). We have analysed only randomised control trials (RCTs) which compared the effectiveness of corticosteroid injections with control injections. Methods: The Cochrane Library, PubMed, Medline, Web of Science and Scopus were searched to identify relevant studies. The keywords for search in the database were ('stenosing tenosynovitis' OR 'trigger finger') AND injections. After screening titles and abstracts of these studies, full-text articles of studies that fulfilled the selection criteria were obtained. For the meta-analysis, we determined the pooled mean failure rate, odds ratio (OR), relative risk (RR) and 95% confidence intervals (CI) for the risk of failure rate between the corticosteroid injection group and the control group through the random-effects model. Results: Six RCTs were found that involved 368 participants. The corticosteroid injection group included 190 patients and 178 patients were included in the control group. The pooled estimate of successful treatment in the corticosteroid injections group was 63.68 ± 5.32% and that in the control group was 27.53 ± 11.52%. The pooled RR of treatment failure between the corticosteroid injection group and the control group was 0.49 (95% CI 0.40-0.60). The pooled OR of treatment failure between the corticosteroid injection group and the control group was 0.18 (95% CI 0.08-0.44). All the included studies reported either mild or no complications with corticosteroids or placebo injections. Conclusions: In the treatment of stenosing tenosynovitis, the corticosteroid injections have better outcomes compared to the control injections and this meta-analysis provides significant evidence of the effectiveness of corticosteroid injection for stenosing tenosynovitis with minimal adverse effects. Level of Evidence: Level II (Therapeutic).

Evaluation of vapocoolant spray effect on pain reduction during digital nerve block: A randomized clinical trial

INTRODUCTION

The digital nerve block is an effective method of anesthesia before minor surgical interventions on the fingers. However, patients may experience a lot of pain and anxiety during this procedure. The efficacy of topical vapocoolant spray during minor procedures has been demonstrated in previous studies. we aimed to evaluate the effectiveness of topical vapocoolant spray in reducing pain during digital nerve block.

METHODS

This prospective, randomized clinical study was conducted to evaluate the effectiveness of vapocoolant spray application in reducing pain during digital block. The patients were categorized into 2 groups as spray-treated and control group. A routine digital block process was applied to the control group. Spray application was performed in two groups of 50 each, in a manner of bilateral and unilateral to the finger. Demographic data of the patients, such as gender, age, dominant hand, injury patterns, injection site and injury sites, were recorded. After the application, the patients' visual analog scale (VAS) was evaluated.

RESULTS

Of the participants, 100 were randomly assigned to the vapocoolant spray-treated group, and 50 were included in the control group. The VAS pain score during penetration in both spray groups was significantly lower than the control group (p < 0.001). Pain change during penetration was found to be significantly lower in the bilateral spray-treated group compared to the control group (p < 0.001). Pain change during infiltration was significantly lower in both spray groups compared to the control group (p < 0.001).

CONCLUSIONS

Spray application prior to digital nerve blocking can be used to reduce needle penetration pain associated with this procedure and pain associated with local anesthetic infiltration.

Non-steroidal anti-inflammatory drugs (NSAIDs) for trigger finger

BACKGROUND

Trigger finger is a common hand condition that occurs when movement of a finger flexor tendon through the first annular (A1) pulley is impaired by degeneration, inflammation, and swelling. This causes pain and restricted movement of the affected finger. Non-surgical treatment options include activity modification, oral and topical non-steroidal anti-inflammatory drugs (NSAIDs), splinting, and local injections with anti-inflammatory drugs.

OBJECTIVES

To review the benefits and harms of non-steroidal anti-inflammatory drugs (NSAIDs) versus placebo, glucocorticoids, or different NSAIDs administered by the same route for trigger finger.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, CNKI (China National Knowledge Infrastructure), ProQuest Dissertations and Theses, www.ClinicalTrials.gov, and the WHO trials portal until 30 September 2020. We applied no language or publication status restrictions.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) and quasi-randomised trials of adult participants with trigger finger that compared NSAIDs administered topically, orally, or by injection versus placebo, glucocorticoid, or different NSAIDs administered by the same route.

DATA COLLECTION AND ANALYSIS

Two or more review authors independently screened the reports, extracted data, and assessed risk of bias and GRADE certainty of evidence. The seven major outcomes were resolution of trigger finger symptoms, persistent moderate or severe symptoms, recurrence of symptoms, total active range of finger motion, residual pain, patient satisfaction, and adverse events. Treatment effects were reported as risk ratios (RRs) and mean differences (MDs) with 95% confidence intervals (CIs).

MAIN RESULTS

Two RCTs conducted in an outpatient hospital setting were included (231 adult participants, mean age 58.6 years, 60% female, 95% to 100% moderate to severe disease). Both studies compared a single injection of a non-selective NSAID (12.5 mg diclofenac or 15.0 mg ketorolac) given at lower than normal doses with a single injection of a glucocorticoid (triamcinolone 20 mg or 5 mg), with maximum follow-up duration of 12 weeks or 24 weeks. In both studies, we detected risk of attrition and performance bias. One study also had risk of selection bias. The effects of treatment were sensitive to assumptions about missing outcomes. All seven outcomes were reported in one study, and five in the other. NSAID injection may offer little to no benefit over glucocorticoid injection, based on low- to very low-certainty evidence from two trials. Evidence was downgraded for bias and imprecision. There may be little to no difference between groups in resolution of symptoms at 12 to 24 weeks (34% with NSAIDs, 41% with glucocorticoids; absolute effect 7% lower, 95% confidence interval (CI) 16% lower to 5% higher; 2 studies, 231 participants; RR 0.83, 95% CI 0.62 to 1.11; low-certainty evidence). The rate of persistent moderate to severe symptoms may be higher at 12 to 24 weeks in the NSAIDs group (28%) compared to the glucocorticoid group (14%) (absolute effect 14% higher, 95% CI 2% to 33% higher; 2 studies, 231 participants; RR 2.03, 95% CI 1.19 to 3.46; low-certainty evidence). We are uncertain whether NSAIDs result in fewer recurrences at 12 to 24 weeks (1%) compared to glucocorticoid (21%) (absolute effect 20% lower, 95% CI 21% to 13% lower; 2 studies, 231 participants; RR 0.07, 95% CI 0.01 to 0.38; very low-certainty evidence). There may be little to no difference between groups in mean total active motion at 24 weeks (235 degrees with NSAIDs, 240 degrees with glucocorticoid) (absolute effect 5% lower, 95% CI 34.54% lower to 24.54% higher; 1 study, 99 participants; MD -5.00, 95% CI -34.54 to 24.54; low-certainty evidence). There may be little to no difference between groups in residual pain at 12 to 24 weeks (20% with NSAIDs, 24% with glucocorticoid) (absolute effect 4% lower, 95% CI 11% lower to 7% higher; 2 studies, 231 participants; RR 0.84, 95% CI 0.54 to 1.31; low-certainty evidence). There may be little to no difference between groups in participant-reported treatment success at 24 weeks (64% with NSAIDs, 68% with glucocorticoid) (absolute effect 4% lower, 95% CI 18% lower to 15% higher; 1 study, 121 participants; RR 0.95, 95% CI 0.74 to 1.23; low-certainty evidence). We are uncertain whether NSAID injection has an effect on adverse events at 12 to 24 weeks (1% with NSAIDs, 1% with glucocorticoid) (absolute effect 0% difference, 95% CI 2% lower to 3% higher; 2 studies, 231 participants; RR 2.00, 95% CI 0.19 to 21.42; very low-certainty evidence).

AUTHORS' CONCLUSIONS

For adults with trigger finger, by 24 weeks' follow-up, results from two trials show that compared to glucocorticoid injection, NSAID injection offered little to no benefit in the treatment of trigger finger. Specifically, there was no difference in resolution, symptoms, recurrence, total active motion, residual pain, participant-reported treatment success, or adverse events.

Reduction in pain from corticosteroid injection for the treatment of trigger finger with subcutaneous single-injection digital block: a randomized controlled trial

PURPOSE

The pain from corticosteroid injections is not an insignificant issue for patients with trigger finger. The aim of this study was to evaluate the efficacy of subcutaneous single-injection digital block (SSIDB) for pain reduction during trigger finger corticosteroid injection.

METHODS

Ninety patients requiring corticosteroid injections for trigger finger were randomized to three groups: SSIDB with 2 ml of 1% lidocaine, SSIDB with 1 ml of 1% lidocaine and no digital block (control group). In SSIDB groups, the intrasynovial corticosteroid injections were performed after digital nerve block. In control group, ethyl chloride spray was applied prior to intrasynovial injection of the corticosteroid and 1% lidocaine mixture. The pain during lidocaine needle insertion, lidocaine infiltration, corticosteroid needle insertion and corticosteroid infiltration were determined with a visual analog scale (VAS).

RESULTS

The VAS pain scores for corticosteroid needle insertion in both SSIDB groups were significantly lower than the VAS pain scores in control group (p < 0.001). The VAS pain score during corticosteroid infiltration in 2 ml of 1% lidocaine group was significantly lower than 1 ml of 1% lidocaine group (p = 0.008), and in control group (p < 0.001). Pain during nerve block procedure in both SSIDB groups was significantly lower than the pain from corticosteroid injection in the control group (p < 0.05 and p < 0.05).

CONCLUSIONS

Subcutaneous single-injection digital block with 2 ml of 1% lidocaine was highly effective in reducing pain associated with injection of corticosteroid for trigger finger.

Clinical indications for image-guided interventional procedures in the musculoskeletal system: a Delphi-based consensus paper from the European Society of Musculoskeletal Radiology (ESSR)-Part II, elbow and wrist

BACKGROUND

Although image-guided interventional procedures of the elbow and wrist are routinely performed, there is poor evidence in the literature concerning such treatments. Our aim was to perform a Delphi-based consensus on published evidence on image-guided interventional procedures around the elbow and wrist and provide clinical indications on this topic.

METHODS

A board of 45 experts in image-guided interventional musculoskeletal procedures from the European Society of Musculoskeletal Radiology were involved in this Delphi-based consensus study. All panelists reviewed and scored published papers on image-guided interventional procedures around the elbow and wrist updated to September 2018 according to the Oxford Centre for Evidence-based Medicine levels of evidence. Consensus on statements drafted by the panelists about clinical indications was considered as "strong" when more than 95% of panelists agreed and as "broad" if more than 80% agreed.

RESULTS

Eighteen statements were drafted, 12 about tendon procedures and 6 about intra-articular procedures. Only statement #15 reached the highest level of evidence (ultrasound-guided steroid wrist injections result in greater pain reduction and greater likelihood of attaining clinically important improvement). Seventeen statements received strong consensus (94%), while one received broad consensus (6%).

CONCLUSIONS

There is still poor evidence in published papers on image-guided interventional procedures around the elbow and wrist. A strong consensus has been achieved in 17/18 (94%) statements provided by the panel on clinical indications. Large prospective randomized trials are needed to better define the role of these procedures in clinical practice.

KEY POINTS

• The panel provided 18 evidence-based statements on clinical indications of image-guided interventional procedures around the elbow and wrist. • Only statement #15 reached the highest level of evidence: ultrasound-guided steroid wrist injections result in greater pain reduction and greater likelihood of attaining clinically important improvement. • Seventeen statements received strong consensus (94%), while broad consensus was obtained by 1 statement (6%).

Ultrasound Features of Trigger Finger: Review of the Literature

Trigger finger is a common pathologic condition of the digital pulleys and flexor tendons in the hand. The key clinical finding is a transient blockage of the digit when it is flexed with subsequent painful snapping when it is extended. Imaging is a helpful guide for establishing the severity of the disease, identifying the underlying cause, and deciding the appropriate management. This narrative review aims to recall the anatomic and pathologic bases and describe the ultrasound features of trigger finger, also including common ultrasound findings and complications after therapy. Ultrasound enables an accurate static and dynamic evaluation of trigger finger as well as a comparison with the adjacent normal digits and thus should be considered the radiologic modality of first choice for its diagnosis.

Effect of metacarpophalangeal joint position on A1 pulley and flexor digitorum tendons in trigger digit

BACKGROUND

The aim of this study was to evaluate and compare the cross-sectional area (CSA) of flexor digitorum tendons and the thickness of first annular (A1) pulleys between contralateral normal digits and trigger digits (TDs) at positions of finger flexion and extension using a noninvasive ultrasound system.

METHODS

Seventeen affected fingers of 17 patients (6 men and 11 women) with TDs in one hand, and 17 contralateral normal digits without trigger finger symptoms were examined. The sonographic appearances of flexor digitorum tendons and A1 pulleys were observed at two positions of metacarpophalangeal (MCP) joint flexion: 0° and 60°.

RESULTS

The findings of this study indicate that CSA of flexor digitorum tendons and A1 pulley thickness were significantly larger in both positions of 0° and 60° flexion of MCP joint compared with contralateral normal digits (p < 0.01). In TDs, there was a significantly thicker A1 pulley at 60° flexion of MCP joint than that at 0° flexion (p < 0.01), but no significant change on CSA of flexor tendons.

CONCLUSION

Our results suggested that TDs lead to the thicker A1 pulley and larger CSA of the flexor digitorum tendons. The mismatch in volume change between CSA of flexor digitorum tendons and A1 pulley thickness during MCP flexion may lead to the trigger phenomenon.

Upper Limb Interventions

Ultrasound has been reported to be a quick, cheap, and effective imaging modality to guide the interventional procedures in the musculoskeletal system. The use of ultrasound results in increased accuracy of needle placement associated with a reduction of complications. In the upper limb, ultrasound-guided procedures are applied to joints and soft tissues around the shoulder, elbow, wrist, and hand. This article reviews the clinical and technical aspects of the most common procedures performed in this anatomic area.

Interventional therapeutic procedures to treat degenerative and inflammatory musculoskeletal conditions: state of the art

Imaging-guided interventional procedures have become increasingly popular in the treatment of several pathologic conditions in the musculoskeletal system. Besides oncological treatments, musculoskeletal procedures can be performed to treat different degenerative or inflammatory conditions. This paper is aimed to review clinical indications and technical aspects of these kinds of procedures. In particular, we revise the general aspects common to most procedures and the different imaging-guided interventions which can be performed around joints, soft tissues, and spine.

Cost-Effective Management of Stenosing Tenosynovitis

PURPOSE

Stenosing tenosynovitis (STS) is a common condition treated by hand surgeons. Limited evidence exists to support the nonsurgical management of STS. The purpose of this study was to prospectively evaluate a cohort of patients with STS, and to determine the strategy for treating patients with this condition that is most cost effective in terms of dollars reimbursed by payers.

METHODS

Prospective data were collected on patients diagnosed with STS between March 2014 and September 2014. All patients were initially treated with a corticosteroid injection. Patients with persistent symptoms were given the option of injection or surgery. A maximum of 3 injections were offered. All patients were evaluated every 6 months through office appointments or phone calls. A cost analysis was performed in our cohort using actual reimbursement rates for injections, initial and established patient visits, and facility and physician fees for surgery, using the reimbursement rates from the 6 payers covering this patient cohort. Cost savings were calculated based on offering 1, 2, and 3 injections.

RESULTS

Eighty-eight digits in 82 patients were followed for an average of 21.9 months (range, 18.7-22.7 mo) after an initial corticosteroid injection. Thirty-five digits went on to surgical release, whereas 53 digits were treated nonsurgically. Had all patients initially undergone surgery, the cost would have totaled $169,088.98 ($1,921 per digit). Offering up to 3 injections yielded a potential savings of $72,730 ($826 per digit) or 43% of the total cost. For the 33 patients who underwent more than 1 injection, offering a second injection yielded potential savings of $15,956 ($484 per digit, 22.7%), and for the 7 patients presenting a third time, a third injection saved $1,986 ($283 per digit, 14.5%).

CONCLUSIONS

Based on the data from our cohort, the efficient way to treat STS in terms of health care dollars spent is to offer up to 3 injections before surgical release. The first injection had the highest component of cost savings, at $826 per digit.

TYPE OF STUDY/LEVEL OF EVIDENCE

Economic/Decision Analysis III.

Different Dosages of Triamcinolone Acetonide Injection for the Treatment of Trigger Finger and Thumb: A Randomized Controlled Trial

BACKGROUND

This study was designed to compare the efficacy and complications between 3 different dosages of triamcinolone acetonide for the treatment of trigger finger.

METHODS

Ninety-three patients with a total of 120 trigger digits were included in the study. The involved digits were randomized to 3 groups. Each group received treatment consisting of injection with 5, 10 or 20 mg triamcinolone acetonide. The clinical response to the steroid was evaluated during the first six weeks after injection. The success rate was determined at 3, 6, 9 and 12 months after injection.

RESULTS

After the injections, pain and triggering improved gradually and nearly resolved completely at 6 weeks in all dosages. A dose related pattern was found at 3 and 6 months after the injection. The 20 mg group had a significant higher success rate when compared to the 5 and 10 mg at 3 and 6 months. The 10 mg group has significant higher success rate when compare to 5 mg at 3 months. There were no differences of success rate between groups at 9 and 12 months. At 12 months, 7 of 40 digits (17.5%) in the 5 mg group, 7 of 40 digits (17.5%) in the 10 mg group, and 9 of 40 digit (22.5%) in the 20 mg group were without triggering (p = 0.806).

CONCLUSIONS

A dose-response characteristic was demonstrated in the treatment of trigger finger with triamcinolone acetonide. Triamcinolone acetonide 5 mg seems to have the lowest success rate.

Intra-sheath versus extra-sheath ultrasound guided corticosteroid injection for trigger finger: a triple blinded randomized clinical trial

OBJECTIVE

The aim of this study is to compare clinical results of ultrasound-guided corticosteroid injection, intra-sheath versus extra-sheath of the finger flexor tendon.

METHODS

A total of 166 patients with trigger finger were evaluated in a triple blind randomized clinical trial study. All the patients were injected with 1ml of 40mg/ml methyl prednisolone acetate, under the guidance of ultrasound. Half the patients were injected extra sheath, while the other half were injected intra sheath at the level of first annular pulley.

RESULTS

The two groups were comparable in baseline characteristics (age, gender, dominant hand, involved hand and finger, and the symptoms duration). No significant difference was observed in the two groups with regards to Quinnell grading. In the final visit, 94% of patients from each group were symptom free.

CONCLUSION

Results of corticosteroid injection intra-sheath or extra-sheath of the finger flexor tendon under ultrasound guidance in patients with trigger finger are comparably alike. Extra-sheath injection at the level of A1 pulley is as effective as an Intra-sheath administration.

Open Surgery Versus Ultrasound-Guided Corticosteroid Injection for Trigger Finger: A Randomized Controlled Trial With 1-Year Follow-up

PURPOSE

Trigger finger is a common condition with a lifetime prevalence of 2%. Corticosteroid injection is a treatment often considered as a first-line intervention with reported cure rates between 60% and 90% in observational cohorts. Nevertheless, open surgery remains the most effective treatment with reported cure rates near 100%. Head-to-head trials on these treatments are limited. We investigated the efficacy of open surgery compared with ultrasound-guided corticosteroid injections.

METHODS

The study was performed as a single-center, randomized, controlled trial with a 1-year follow-up. A total of 165 patients received either open surgery (n = 81) or ultrasound-guided corticosteroid injection (n = 84). Follow-up was conducted at 3 and 12 months. If the finger had normal movement or normal movement with discomfort at latest follow-up, the outcome was considered a success. Secondary outcomes were postprocedural pain and complications.

RESULTS

The groups were similar at baseline except for lower alcohol consumption in the open surgery group. At 3 months, 86% and 99% were successfully treated after corticosteroid injection and open surgery, respectively. At 12 months, 49% and 99% were considered successfully treated after corticosteroid injection and open surgery, respectively. The pain score at latest follow-up was significantly higher in the corticosteroid injection group. Complications after open surgery were more severe and included 3 superficial infections and 1 iatrogenic nerve lesion. After corticosteroid injection 11 patients experienced a steroid flare and 2 had fat necrosis at the site of injection.

CONCLUSIONS

Open surgery is superior to ultrasound-guided corticosteroid injections. Complications after open surgery are more severe; this must be taken into account when advising patients with regard to treatment.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic I.

Ultrasound-Guided Interventional Procedures of the Wrist and Hand: Anatomy, Indications, and Techniques

Acute and chronic wrist and hand conditions are commonly seen by neuromuscular and musculoskeletal specialists. High-frequency diagnostic ultrasonography (US) has facilitated advances in the diagnosis and interventional management of wrist and hand disorders. US provides excellent soft tissue resolution, accessibility, portability, lack of ionizing radiation, and the ability to dynamically assess disorders and precisely guide interventional procedures. This article review the relevant anatomy, indications, and interventional techniques for common disorders of the wrist and hand, including radiocarpal joint arthritis, scaphotrapeziotrapezoidal joint arthritis, trapeziometacarpal joint arthritis, phalangeal joint arthritis, first dorsal compartment tenosynovitis, ganglion cysts, and stenosing tenosynovitis.

Identification of the Position and Thickness of the First Annular Pulley in Sonographic Images

The purpose was to identify the A1 pulley's exact location and thickness by comparing measurements from a clinical high-frequency ultrasound scanner system (CHUS), a customized high-frequency ultrasound imaging research system (HURS) and a digital caliper. Ten cadaveric hands were used. We explored the pulley by layers, inserted guide pins and scanned it with the CHUS. After identifying the pulley, we measured each long finger's thickness using the CHUS and excised the pulley to measure its thickness with a digital caliper and the HURS. The thin hypo-echoic layer was revealed to be the synovial fluid space, and the pulley appears hyper-echoic regardless of scan direction. We also defined the pulley's boundaries. Moreover, the CHUS provided a significantly lower measurement of the pulley's thickness than the digital caliper and HURS. Likewise, based on the digital caliper's measurement, the HURS had significantly lower mean absolute and relative errors than the CHUS.

Ultrasound-guided procedures in rheumatology. What is the evidence?

Ultrasound (US) is a cost-effective, noninvasive, and accessible imaging modality that clinicians use at the point of care to assess disease activity and therapeutic efficacy in different rheumatic conditions. It can play a relevant role in invasive procedures performed by the rheumatologist, potentially ensuring a higher degree of accuracy. However, US-guided injections are still underused, and the conventional blind injection the most commonly adopted approach. In this article, we analyze the current evidence supporting the use of US-guided procedures, emphasizing comparative studies between conventional and US-guided procedures and their benefits in the daily rheumatological practice.

Sonographic evaluation of effects of the volar plate on trigger finger

BACKGROUND

We evaluated trigger fingers ultrasonographically and clarified differences between fingers with and without continuous locking or snapping symptoms according to the thicknesses of the A1 pulley, flexor tendon and volar plate.

METHODS

We evaluated 26 trigger fingers, divided into two groups: Group 1, 14 fingers with locking or snapping; and Group 2, 12 fingers without such symptoms. We also evaluated 26 contralateral fingers as controls (Control 1 and 2 groups). We compared each group to the respective control group according to thickness of the A1 pulley and volar plate, and cross-sectional area of the flexor tendon. In addition, nine fingers with locking or snapping and treated using corticosteroid injection were evaluated according to symptoms and sonographic findings 3-4 weeks after treatment.

RESULTS

Thickness of the A1 pulley and cross-sectional area of the flexor tendon were greater in both Groups 1 and 2 than in controls. Thickness of the volar plate was greater in Group 1 than in Control 1, although no significant difference was seen between Group 2 and Control 2. In Group 1, eight of the nine fingers showed an alleviation of locking or snapping symptoms with corticosteroid injection, and sonographic findings showed that thickness of the volar plate was significantly decreased with corticosteroid injection, in addition to reduced thickness of the A1 pulley.

CONCLUSION

In addition to thickening of the A1 pulley, thickening of the volar plate may represent an important contributor to continuous snapping or locking symptoms.

Evolving Role of Ultrasound in Therapeutic Injections of the Upper Extremity

Ultrasound machines are creating more refined pictures and becoming more user-friendly and readily accessible. As a result, ultrasound is being increasingly used for therapeutic purposes. One example involves the use of ultrasound guidance in musculoskeletal interventional procedures, such as joint injections, tendon sheath injections, and peripheral nerve blocks. Technical considerations and therapeutic results have been described for multiple locations about the upper extremities, with varying levels of success. The implementation of ultrasound-guided injections in the orthopedist's clinic has therapeutic, financial, and provider role implications. Given these potential benefits, orthopedic providers, both in practice and residency, would benefit from increased exposure and education in ultrasound use. Ultrasound provides the benefit of real-time, dynamic imaging without the radiation exposure of fluoroscopy, and ultrasound-guided injections can be performed in the office, as opposed to the operating room, which is frequently required when using fluoroscopy. A basic knowledge of the principles and terms used in ultrasound is required. With these simple principles, a practitioner can review techniques for specific areas of the musculoskeletal system and begin using ultrasound to guide injections. Many locations for diagnostic and/or therapeutic injections in the upper extremities have improved accuracy and benefit with the use of ultrasound vs blind techniques, although a few have not been shown to have a significant difference in the literature. The educational and professional implications can be significant, but these potential benefits need to be carefully weighed against costs by each orthopedic practice.

Radiological intervention of the hand and wrist

The role of radiological guided intervention is integral in the management of patients with musculoskeletal pathologies. The key to image-guided procedures is to achieve an accurately placed intervention with minimal invasion. This review article specifically concentrates on radiological procedures of the hand and wrist using ultrasound and fluoroscopic guidance. A systematic literature review of the most recent publications relevant to image-guided intervention of the hand and wrist was conducted. During this search, it became clear that there is little consensus regarding all aspects of image-guided intervention, from the technique adopted to the dosage of injectate and the specific drugs used. The aim of this article is to formulate an evidence-based reference point which can be utilized by radiologists and to describe the most commonly employed techniques.

Ultrasound-Guided Hyaluronic Acid Injections for Trigger Finger: A Double-Blinded, Randomized Controlled Trial

OBJECTIVES

To investigate the effects of ultrasound-guided injections of hyaluronic acid (HA) versus steroid for trigger fingers in adults.

DESIGN

Prospective, double-blinded, randomized controlled study.

SETTING

Tertiary care center.

PARTICIPANTS

Subjects with a diagnosis of trigger finger (N=36; 39 affected digits) received treatment and were evaluated.

INTERVENTIONS

Subjects were randomly assigned to HA and steroid injection groups. Both study medications were injected separately via ultrasound guidance with 1 injection.

MAIN OUTCOME MEASURES

The classification of trigger grading, pain, functional disability, and patient satisfaction were evaluated before the injection and 3 weeks and 3 months after the injection.

RESULTS

At 3 months, 12 patients (66.7%) in the HA group and 17 patients (89.5%) in the steroid group exhibited no triggering of the affected fingers (P=.124). The treatment results at 3 weeks and 3 months showed similar changes in the Quinnell scale (P=.057 and .931, respectively). A statistically significant interaction effect between group and time was found for visual analog scale (VAS) and Michigan Hand Outcome Questionnaire (MHQ) evaluation (P<.05). The steroid group had a lower VAS at 3 months after injection (steroid 0.5±1.1 vs HA 2.7±2.4; P<.001). The HA group demonstrated continuing significant improvement in MHQ at 3 months (change from 3wk: steroid -2.6±14.1 vs HA 19.1±37.0; P=.023; d=.78).

CONCLUSIONS

Ultrasound-guided injection of HA demonstrated promising results for the treatment of trigger fingers. The optimal frequency, dosage, and molecular weight of HA injections for trigger fingers deserve further investigation for future clinical applications.

Corticosteroid injection for trigger finger: blinded or ultrasound-guided injection?

INTRODUCTION

Trigger digit is one of the most common causes of pain and disability in the hand. The mainstay of conservative treatment of this disease has been local steroid injection into the tendon sheath. The aim of this study was to investigate the clinical benefit of an ultrasound-guided corticosteroid injection compared to a blinded application.

MATERIALS AND METHODS

74 patients, who suffered from persistent or increasing symptoms of a single trigger digit, were enroled in this prospective, randomised case-control study. All patients were treated with an injection of 40 mg/1 ml methylprednisolone acetate into the flexor tendon sheath at the level of the A1 pulley. Half of the patients had their injections under ultrasound control (USG) and half without (blinded injection group, BIG). Associated metabolic diseases were recorded. At the 6-week and 6-month follow-up examinations, the complication rate and the need for a second injection were assessed. The outcome was rated using the Quinnell grading. The pain level was assessed using the visual analogue scale.

RESULTS

Four patients were excluded due to lack of follow-up. Both study groups were comparable in respect of age, hand dominance and associated diseases. There were significantly more female patients in the USG group (32 versus 23 %). After the corticosteroid injections, all patients improved significantly in terms of pain level and the Quinnell grading at 6 weeks and 6 months after the intervention in comparison to the pre-injection status. There were no significant differences between the groups. 9 patients (13 %) needed a second injection (6 of BIG, 3 of USG), all of whom had diabetes mellitus. No local complications were seen after the injections.

CONCLUSION

The use of ultrasound-guided injection of corticosteroid may be associated with extra time and effort, with no superior clinical benefits compared to the blinded technique.

LEVEL OF EVIDENCE

Level 1(prospective randomised study).

Temporary inductions of matrix metalloprotease-3 (MMP-3) expression and cell apoptosis are associated with tendon degeneration or rupture after corticosteroid injection

Corticosteroid injections are widely used to treat enthesopathy and tendinitis, but are also associated with possible side effects, such as tendon degeneration or rupture. However, the mechanism of tendon degeneration or rupture after corticosteroid injection remains controversial. The purpose of this study was to reveal the mechanism of tendon degeneration or rupture after injection of triamcinolone acetonide (TA) or prednisolone (PSL). Forty-two rats were divided into 3 groups: A normal saline injection group (control group), a TA injection group, and a PSL injection group; the normal saline or corticosteroid was injected around the Achilles tendon. One or 3 weeks after injection, the tendons were subjected to biomechanical testing and histological analysis. At 1 week, the biomechanical strength was significantly lower in the corticosteroid groups. Histological analysis, at 1-week post-injection, showed collagen attenuation, increased expression of MMP-3 and apoptotic cells in the corticosteroid groups. The histological changes and biomechanical weaknesses of the tendon were not seen at 3 weeks. These alterations appeared to be involved in tendon degeneration or rupture after corticosteroid injection.

Ultrasound-guided procedures around the wrist and hand: how to do

Ultrasound has emerged as a low-cost, radiation-free and effective imaging technique to detect joint abnormalities and to guide percutaneous procedures. Being superficial, wrist and hand tendons and joints represent a good target to perform such procedures using ultrasound guidance. This kind of approach allows for a clear and real-time visualization of the needles during their whole path. In this setting, the knowledge of technical aspects and tips is essential to act in the most accurate way on target tissues that can be as small as a few millimetres. The aim of this review is to summarize the local treatments of inflammatory and degenerative disease described in literature (such as treatment of De Quervain's tenosynovitis, trigger finger, trapezio-metacarpal joint osteoarthritis, etc.), emphasizing precautions and tricks based on day-by-day experience that may help to improve the outcome of percutaneous ultrasound-guided procedures around the wrist and hand.

Ultrasound-guided corticosteroid injection therapy for juvenile idiopathic arthritis: 12-year care experience

BACKGROUND

Intra-articular corticosteroid injections are a safe and effective treatment for patients with juvenile idiopathic arthritis. The potential scope of care in ultrasound-guided corticosteroid therapy in children and a joint-based corticosteroid dose protocol designed to optimize interdisciplinary care are not found in the current literature.

OBJECTIVE

The purpose of this study was to report the spectrum of care, technique and safety of ultrasound-guided corticosteroid injection therapy in patients with juvenile idiopathic arthritis and to propose an age-weight-joint-based corticosteroid dose protocol.

MATERIALS AND METHODS

A retrospective analysis was performed of 198 patients (ages 21 months to 28 years) referred for treatment of juvenile idiopathic arthritis with corticosteroid therapy. Symptomatic joints and tendon sheaths were treated as prescribed by the referring rheumatologist. An age-weight-joint-based dose protocol was developed and utilized for corticosteroid dose prescription.

RESULTS

A total of 1,444 corticosteroid injections (1,340 joints, 104 tendon sheaths) were performed under US guidance. Injection sites included small, medium and large appendicular skeletal joints (upper extremity 497, lower extremity 837) and six temporomandibular joints. For patients with recurrent symptoms, 414 repeat injections were performed, with an average time interval of 17.7 months (range, 0.5-101.5 months) between injections. Complications occurred in 2.6% of injections and included subcutaneous tissue atrophy, skin hypopigmentation, erythema and pruritis.

CONCLUSION

US-guided corticosteroid injection therapy provides dynamic, precise and safe treatment of a broad spectrum of joints and tendon sheaths throughout the entire pediatric musculoskeletal system. An age-weight-joint-based corticosteroid dose protocol is effective and integral to interdisciplinary care of patients with juvenile idiopathic arthritis.

Musculoskeletal interventional ultrasonography: the upper limb

Forty percent of the 823 ultrasound-guided injections performed in our centre over a year and a half concerned the upper limb, injections involving the shoulder, for subacromial bursitis and the treatment of calcific tendinitis, being the prime indications (24%). The wrist represented 8% of the prescriptions, for treatment of tendinopathy, ganglion cysts, carpal tunnel syndrome and rhizarthrosis. Trigger finger, tenosynovitis and pulley ganglia made up 6% of the indications and the elbow 2.5%. Ultrasound improves the accuracy of the procedure by helping guide the path of the needle and allowing the distribution of the substance injected to be visualised. We shall give details of the technique used for each indication, with advice and hints and post-procedure recommendations.

Ultrasound-guided injection of a corticosteroid and hyaluronic acid: a potential new approach to the treatment of trigger finger

Background and Objectives: Stenosing tenosynovitis (trigger finger) is one of the most common causes of pain and disability in the hand, which may often require treatment with anti-inflammatory drugs, corticosteroid injection, or open surgery. However, there is still large room for improvement in the treatment of this condition by corticosteroid injection. The mechanical, viscoelastic, and antinociceptive properties of hyaluronic acid may potentially support the use of this molecule in association with corticosteroids for the treatment of trigger finger. This study examines the feasibility and safety of ultrasound-guided injection of a corticosteroid and hyaluronic acid compared, for the first time, with open surgery for the treatment of trigger finger.

Methods: This was a monocentric, open-label, randomized study. Consecutive patients aged between 35 and 70 years with ultrasound-confirmed diagnosis of trigger finger were included. Patients were randomly assigned to either ultrasound-guided injection of methylprednisolone acetate 40 mg/mL with 0.8mL lidocaine into the flexor sheath plus injection of 1mL hyaluronic acid 0.8% 10 days later (n = 15; group A), or to open surgical release of the first annular pulley (n = 15; group B). Clinical assessment of the digital articular chain was conducted prior to treatment and after 6 weeks, and 3, 6, and 12 months. The duration of abstention from work and/or sports activity, and any treatment complications or additional treatment requirements (e.g. physiotherapy, compression, medication) were also recorded.

Results: Fourteen patients (93.3%) in group A had complete symptom resolution at 6 months, which persisted for 12 months in 11 patients (73.3%), while three patients experienced recurrences and one experienced no symptom improvements. No patients in group A reported major or minor complications during or after corticosteroid injection, or required a compression bandage. All 15 patients in group B achieved complete resolution of articular impairment by 3 weeks after surgery, but ten patients were assigned to physiotherapy and local and/or oral analgesics for complete resolution of symptoms, which was approximately 30–40 days postsurgery. The mean duration of abstention from work and/or sport was 2–3 days in group A and 26 days in group B.

Conclusions: Although the limited sample size did not allow any statistical comparison between treatment groups, and therefore all the findings should be regarded as preliminary, the results of this explorative study suggest that ultrasound-guided injection of a corticosteroid and hyaluronic acid could be a safe and feasible approach for the treatment of trigger finger. It is also associated with a shorter recovery time than open surgery, which leads to a reduced abstention from sports and, in particular, work activities, and therefore may have some pharmacoeconomic implications, which may be further explored. In light of the promising results obtained in this investigation, further studies comparing ultrasound-guided injection of corticosteroid plus hyaluronic acid with corticosteroid alone are recommended in order to clarify the actual benefits attributable to hyaluronic acid.

Stenosing tenosynovitis

Tenosynovitis refers to an inflammatory condition involving the synovial sheath of a tendon. Stenosing tenosynovitis is a peculiar entity caused by multiple factors, including local anatomy, mechanical factors, and hormonal factors. The main forms include de Quervain tendinopathy; trigger finger (stenosing tenosynovitis involving the flexor digitorum tendons); stenosing tenosynovitis of the extensor carpi ulnaris, extensor carpi radialis, or extensor comunis tendons; stenosing tenosynovitis of the flexor hallucis tendon; and stenosing tenosynovitis of the peroneal tendons. The cardinal finding on ultrasonography is the presence of a thickened retinaculum or pulley that constricts the osseofibrous tunnel through which the tendon runs.

US guided corticosteroid injection into the subacromial-subdeltoid bursa: Technique and approach

Local injection of cortisone derivatives, sometimes combined with local anesthetics, is frequently administered in rheumatology as the treatment of choice in para-articular diseases or as an adjuvant to systemic therapy in the treatment of arthritis.One of the most frequent local corticosteroid injections administered in daily clinical practice by rheumatologists, orthopedic surgeons, physiatrists, sports medicine doctors and general practitioners is injection into the subacromialsubdeltoid bursa in the treatment of bursitis and anterior superior impingement syndrome of the shoulder.Before local corticosteroid injection is administered, it is important to identify possible contraindications and to examine the documentation provided by the patient. Absolute contraindications or those related to the procedure should be evaluated by the prescribing physician but also the physician performing the corticosteroid injection should evaluate possible contraindications to make sure that corticosteroid injection is feasible. The present paper describes the ultrasound (US) guided local corticosteroid injection procedure with particular attention to the equipment required, the position of the patient and the examiner as well as the approach. The main advantage of US guidance during corticosteroid injection is the possibility to identify vascular structures, nerves and tendons situated in the needle path in order to avoid these structures and be sure to inject the drug into the appropriate location. When all rules are complied with and the corticosteroid injection is carried out by an experienced physician, it is virtually painless and is performed in just a few minutes.

Accuracy of sonographically guided and palpation guided scaphotrapeziotrapezoid joint injections

OBJECTIVES

The purpose of this study was to determine and compare the accuracies of sonographically guided and palpation guided scaphotrapeziotrapezoid (STT) joint injections in a cadaveric model.

METHODS

A clinician with 6 years of experience performing sonographically guided procedures injected 1.0 mL of a diluted latex solution into the STT joints of 20 unembalmed cadaveric wrist specimens using a palmar approach. At a minimum of 24 hours after injection, an experienced clinician specializing in hand care completed palpation guided injections in the same specimens using a dorsal approach and 1 mL of a different-colored latex. A fellowship-trained hand surgeon blinded to the injection technique then dissected each specimen to assess injection accuracy. Injections were graded as accurate if the colored latex was found in the STT joint, whereas inaccurate injections resulted in no latex being found in the joint.

RESULTS

All sonographically guided injections were accurate (100%; 95% confidence interval, 81%-100%), whereas only 80% of palpation guided injections were accurate (95% confidence interval, 61%-99%). Sonographically guided injections were significantly more accurate than palpation guided injections, as determined by the ability to deliver latex into the joint (P < .05).

CONCLUSIONS

Sonographic guidance can be used to inject the STT joint with a high degree of accuracy and is more accurate than palpation guidance within the limits of this study design. Clinicians should consider using sonographic guidance to perform STT joint injections when precise intra-articular placement is desired. Further clinical investigation examining the role of sonographically guided STT joint injections in the treatment of patients with radial wrist pain syndromes is warranted.

Sonographically guided tendon sheath injections are more accurate than blind injections: implications for trigger finger treatment

OBJECTIVES

Trigger finger is frequently treated with tendon sheath injections. This cadaveric study evaluated the accuracy and safety of blind and sonographically guided tendon sheath injections. To our knowledge, a study that precisely mapped the locations of material injected into the tendon sheath has not been reported previously.

METHODS

A total of 40 fingers (excluding thumbs) of 5 fresh cadavers were used. Methylene blue dye was injected into the flexor tendon sheath using either a blind or sonographically guided injection technique (20 fingers for each technique). The location of the dye was then determined via dissection.

RESULTS

Dye was observed only in the tendon sheath (ie, optimal outcome) in 70% of sonographically guided injections and 15% of blind injections (P = .001). Dye was observed in the tendon proper (ie, unsafe outcome) in 30% of blind injections and 0% of sonographically guided injections (P = .02).

CONCLUSIONS

We found that sonographically guided tendon sheath injections were more accurate and may be potentially safer than blind injections. These findings suggest that sonographically guided injections should be considered over blind injections when treating trigger finger.

Sonographically guided percutaneous first annular pulley release: cadaveric safety study of needle and knife techniques

OBJECTIVE

The purpose of this study was to assess the safety of sonographically guided percutaneous finger and thumb first annular (A1) pulley releases performed using needle and hook knife techniques in an unembalmed cadaveric model.

METHODS

A single operator completed 50 (40 fingers and 10 thumbs) sonographically guided percutaneous A1 pulley releases in unembalmed cadavers using previously described needle and hook knife techniques and simulated local anesthesia. Half of the fingers and thumbs were completed with each technique. An experienced observer blinded to the technique dissected each specimen and assessed for neurovascular, flexor tendon, and A2 pulley injury. Completeness of release was also recorded as a secondary outcome.

RESULTS

No neurovascular or A2 pulley injury occurred in any digit, regardless of technique. No significant flexor tendon injury was seen in any digit, although minor surface scratches were visualized in 3 cases (6%; 2 knife and 1 needle). The hook knife technique was significantly more likely to result in a complete pulley release compared to the needle technique (22 of 25 [88%] versus 8 of 25 [32%]; P < .001).

CONCLUSIONS

Sonographically guided percutaneous A1 pulley releases can be performed safely using previously described needle and hook knife techniques. The safety margin for thumb releases is less than that for finger releases, particularly with respect to the radial digital nerve. These cadaveric data support recently published clinical investigations recommending consideration of sonographically guided percutaneous A1 pulley release in the management of patients with a disabling trigger finger.

Kinematic evaluation of the finger's interphalangeal joints coupling mechanism--variability, flexion-extension differences, triggers, locking swanneck deformities, anthropometric correlations

The human finger contains tendon/ligament mechanisms essential for proper control. One mechanism couples the movements of the interphalangeal joints when the (unloaded) finger is flexed with active deep flexor. This study's aim was to accurately determine in a large finger sample the kinematics and variability of the coupled interphalangeal joint motions, for potential clinical and finger model validation applications. The data could also be applied to humanoid robotic hands. Sixty-eight fingers were measured in seventeen hands in nine subjects. Fingers exhibited great joint mobility variability, with passive proximal interphalangeal hyperextension ranging from zero to almost fifty degrees. Increased measurement accuracy was obtained by using marker frames to amplify finger segment motions. Gravitational forces on the marker frames were not found to invalidate measurements. The recorded interphalangeal joint trajectories were highly consistent, demonstrating the underlying coupling mechanism. The increased accuracy and large sample size allowed for evaluation of detailed trajectory variability, systematic differences between flexion and extension trajectories, and three trigger types, distinct from flexor tendon triggers, involving initial flexion deficits in either proximal or distal interphalangeal joint. The experimental methods, data and analysis should advance insight into normal and pathological finger biomechanics (e.g., swanneck deformities), and could help improve clinical differential diagnostics of trigger finger causes. The marker frame measuring method may be useful to quantify interphalangeal joints trajectories in surgical/rehabilitative outcome studies. The data as a whole provide the most comprehensive collection of interphalangeal joint trajectories for clinical reference and model validation known to us to date.