Mixed neuropathy presenting clinically as an anterior interosseous nerve palsy following shoulder arthroscopy: a report of four cases

Index Finger Flexor Digitorum Profundus Function Deficit after Shoulder Arthroscopy Treated by Neurolysis: A Case Report

A 60-year-old woman presented functional deficit of the index finger flexor digitorum profundus (FDP) tendon after shoulder arthroscopic rotator cuff repair. As no recovery was observed for 10 months, we conducted an operative exploration of the median nerve and the anterior interosseous nerve, followed by an external neurolysis. The patient recovered FDP function 4.5 months after the second operation. In a patient with persistent isolated FDP dysfunction after shoulder arthroscopy, operative exploration and external neurolysis could facilitate functional recovery. Level of Evidence: Level V (Therapeutic).

Peripheral neuropathies after shoulder arthroscopy: a systematic review

Purpose

Peripheral neuropathies after shoulder arthroscopy are rare, though likely under-reported. Many resolve spontaneously, but some patients are left with permanent neurological deficits. The purpose of this study was to review the literature to better characterize this patient population, diagnostic tests performed, the timing and type of surgical intervention, and report clinical outcomes.

Methods

A systematic literature review was performed. Articles in English were identified from PubMed, EMBASE, and CINAHL in August 2021. Article titles and abstracts were screened for relevance by two authors and discordant abstracts were resolved by the senior author. Data were subsequently extracted from the included articles.

Results

Seventeen articles were identified yielding a total of 91 patients. The average age was 53 ± 12 years, and most patients were male (72%). Rotator cuff repair (62%) was the most common procedure performed. A peripheral neuropathy was identified an average of 80 ± 81 days from the index procedure (range, 0-240 days). Most commonly, peripheral nerve injury presented as a mononeuropathy, with the median nerve (39%) and ulnar nerve (17%) affected predominantly. Seventeen percent of patients underwent a secondary surgery at an average of 232 ± 157 days after the index procedure. At the final follow-up, 55% of neuropathies had resolved, 14% partially improved, and 22% showed no clinical improvement. The most proposed etiologies were postoperative immobilization (29%) and intraoperative positioning (20%), but several possible etiologies have been suggested.

Conclusions

Peripheral neuropathies after arthroscopic shoulder procedures are rare. While most spontaneously resolve, up to 1 in 5 patients may have persistent neuropathic symptoms. A high index of suspicion should be maintained throughout the postoperative period. When neurologic deficits are identified, patients should undergo a thorough diagnostic workup and be referred to a subspecialist in a timely manner.

Anterior Interosseous Nerve Syndrome

Anterior interosseous nerve syndrome (AINS) is a rare form of peripheral neuropathy which involves disruption of the anterior interosseous nerve. The pathophysiology of AINS remains unclear. AINS typically initially presents with forearm pain and may gradually progress to palsy of the deep muscles of the anterior forearm. Diagnosis of AINS requires thorough patient history and physical exam. EMG is the preferred diagnostic study and classically reveals abnormal activity and prolonged latency periods within the evoked action potentials of the FPL and PQ. Due to the self-limiting nature of AINS, there is general agreement that conservative and symptomatic management should be explored for up to 6 months as first line therapy, which usually includes analgesics and nonsteroidal anti-inflammatory drugs, contracture prevention, hand therapy, and hand splinting. Surgical options such as internal neurolysis and minimally invasive endoscopic decompression may be explored if functional recovery from conservative management is limited.

Isolated Anterior Interosseous Neuropathy Affecting Only the Flexor Digitorum Profundus to the Index Finger After Shoulder Arthroscopy: A Case Report and Review of the Literature

ABSTRACT

Anterior interosseous nerve neuropathy is an uncommon neuropathy with multiple potential etiologies. We present a rare case of anterior interosseous nerve neuropathy affecting only the flexor digitorum profundus to the index finger and occurring after shoulder arthroscopy. This unique presentation used a combination of both electrodiagnostic testing and neuromuscular ultrasound to obtain an accurate diagnosis and highlights the importance of these complementary tests in the evaluation of nerve disorders. To our knowledge, anterior interosseous nerve neuropathy after shoulder arthroscopy affecting only the flexor digitorum profundus to the index finger has not been previously described in the literature.

Anterior Interosseous Nerve Palsy After Shoulder Arthroscopy Treated With Surgical Decompression: A Case Series and Systematic Review of the Literature

Background: Anterior interosseous nerve (AIN) palsy is a very uncommon cause of upper extremity pain and weakness that comprises less than 1% of all upper extremity nerve palsies. Rarely reported but also mentioned in the literature is AIN palsy after shoulder arthroscopy. Methods: A systematic review of the literature to date using PubMed was conducted to identify patients who suffered AIN palsy after shoulder arthroscopy procedures. Articles included met the following criteria: (1) published in English; (2) primary presentation of the data; (3) patients had undergone shoulder arthroscopy before developing symptoms of AIN palsy; and (4) diagnosis was confirmed with clinical symptoms of AIN palsy. Measured outcomes included patient demographics, specific shoulder procedure, anesthesia procedure, intra-operative patient positioning, intra-operative compressive dressing, intra-operative traction, surgical versus conservative treatment, abnormal findings during decompression procedure, proposed mechanism of injury, and follow-up. Results: The search yielded 6 articles, of which 4 (13 cases) met inclusion criteria. An additional 2 cases were included in this report totaling 15 cases. The average patient age was 49 years (range: 31-64) with 73% males. At average follow-up of 24 months, 67% of patients experienced complete resolution of symptoms-more than half of which underwent surgical decompression. Patients who failed to progress experienced weakness of the flexor digitorum profundus and flexor pollicis longus muscles. Conclusions: Proposed injury mechanisms for AIN palsy after shoulder arthroscopy range from mechanical trauma, compressive hematoma, and direct anesthetic neurotoxicity. Management should be directed by clinical symptoms, imaging, and patient factors with majority of patients expected to have excellent clinical outcomes.

Fluid Extravasation in Shoulder Arthroscopic Surgery: A Systematic Review

Background

Arthroscopic surgery of the shoulder joint has become increasingly more common given its advantages over open surgery; however, one rare but potentially life-threatening complication is fluid extravasation into the surrounding tissues, causing edema, respiratory compromise, abnormal results on laboratory blood tests, and possibly death. Currently, no systematic review exists that summarizes the existing clinical research on this topic.

Purpose

To perform a systematic review on fluid extravasation as a complication of shoulder arthroscopic surgery, specifically assessing clinical presentation, risk factors, management, and outcomes.

Study Design

Systematic review; Level of evidence, 4.

Methods

Two reviewers independently searched 3 databases (PubMed, Ovid [MEDLINE], and Embase) from database inception until July 1, 2017. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) checklist guided the reporting and data abstraction. The methodological quality of these studies was assessed using the Methodological Index for Non-Randomized Studies (MINORS) checklist. The results are presented in a narrative summary fashion using descriptive statistics including ranges and agreement statistics.

Results

A total of 26 studies (20 case reports, 4 case series, and 2 prospective comparative studies) encompassing 205 patients (mean age, 50.8 years [range, 15-83 years]) were included. The most common signs of fluid extravasation included chest wall swelling (n = 86) and neck swelling (n = 116). In 32 patients, observation alone was sufficient. Other patients required airway intubation (n = 16), diuretics (n = 7), steroids (n = 1), and percutaneous drainage of fluid (n = 1). Clinical edema resolved after 2 to 48 hours, and patients were discharged 1 to 20 days postoperatively. Serious complications included transfer to the intensive care unit (n = 14), anterior interosseous nerve palsy (n = 4), rhabdomyolysis (n = 1), and death (n = 1).

Conclusion

Fluid extravasation has the potential to be a life-threatening complication of shoulder arthroscopic surgery; however, it is most commonly managed nonoperatively, and symptoms typically resolve with no evidence of long-term complications. Intraoperative surgical decisions, such as minimizing the surgical time and volume of irrigation fluid used, may limit fluid extravasation, while careful intraoperative monitoring may facilitate prompt diagnosis and management to optimize patient outcomes.