Tibial intraneural ganglion cysts arising from the tibiofemoral joint: illustrative cases.

Background: Intraneural cysts involving the tibial nerve in the knee region (popliteal fossa) are rare. According to the articular (synovial) theory, which posits a joint origin for this pathology, these cysts originate from either the superior tibiofibular joint (STFJ) or the tibiofemoral (knee) joint. As tibial intraneural cysts arising from the tibiofemoral joint remain poorly understood, the authors present 2 illustrative cases and a review of the world's literature on all tibial intraneural ganglion cysts in the knee region.

Posterior interosseous nerve paralysis secondary to an extraneural ganglion cyst from a radial neck pseudarthrosis: illustrative case.

Background: Many benign and malignant tissue or bony lesions have been reported as causes of extrinsic or intrinsic posterior interosseous nerve (PIN) neuropathy at the proximal forearm/elbow region. The authors describe an unusual cause of external compression of the PIN due to a ganglion cyst arising from a radial neck pseudarthrosis (a false joint).

Observations: Decompression of the PIN with the release of the arcade of Frohse was performed with resection of the radial head and the ganglion cyst.

Perineurioma of the sciatic nerve with reticular, microcystic, and pseudolipoblastic features: illustrative case.

Background: Perineuriomas are peripheral nerve sheath tumors that are composed of benign, localized proliferations of perineural cells and further subclassified as intraneural or extraneural (soft tissue) based on their relationship to the histological boundaries of the nerve. Multiple histological variants have been described, and herein the authors present the first known case of a pseudolipoblastic perineurioma affecting the nerve.

Observations: A 52-year-old woman presented with a 5-year history of progressive, severe left buttock pain radiating down to the top of her foot and ankle, without any associated weakness, with a large mass in her sciatic nerve noted on magnetic resonance imaging (MRI).

Peroneal intraneural ganglion cyst with a nearly invisible joint connection (even to advocates of the articular theory): illustrative case.

Background: The articular (synovial) theory describes the formation of intraneural ganglion cysts through defects in the capsule of synovial joints. While the articular theory is gaining significant traction in the literature, it is not universally accepted. Therefore, the authors present a case of a plainly visible peroneal intraneural cyst, although the subtle joint connection was not identified specifically at the time of surgery, with subsequent rapid extraneural cyst recurrence.

Plexal intraneural perineurioma: an analysis of the clinicoradiologic presentation of this rare variant.

Purpose: Intraneural (IN) perineurioma is a rare benign peripheral nerve sheath tumor, typically presenting as a painless, progressive mononeuropathy in adolescents. A rare plexal variant has been described, although there are little data describing its clinicoradiologic features. Herein, we present the largest case series of plexal IN perineuriomas reported in the literature.

Hybrid tumors with perineurioma components: a systematic review of the literature and illustrative case.

Purpose: Hybrid peripheral nerve sheath tumors (HPNST) are a newly recognized class of peripheral nerve sheath tumor, composed of at least two areas characteristic of perineurioma, schwannoma, or neurofibroma. The literature consists only of case reports and small series; therefore, we present an illustrative case and an analysis of all reported cases of HPNST with a perineurioma component in the literature.

Methods: A systematic search of the literature was performed to identify all reported cases of hybrid perineurioma-schwannoma or perineurioma-neurofibroma in the world's literature.

The value of high-resolution imaging in an occult peroneal intraneural ganglion cyst: illustrative case.

Background: Foot drop is a common complaint with a broad differential diagnosis making imaging a key part of the diagnostic workup. The authors present a patient with an occult peroneal intraneural ganglion cyst who underwent imaging with high-frequency ultrasound (US) and high-resolution magnetic resonance imaging (MRI) to highlight the role of such techniques in cases of peroneal neuropathy.

Observations: Intraneural ganglion cysts are emerging as a common cause of common peroneal neuropathy.

Reconstruction of Triangular Fibrocartilage Complex Avulsions (Palmar 1C) with Associated Lunotriquetral and Dorsal Capsule Injury: A Case Report.

Case: A 34-year-old farmer and railroad worker injured his left wrist when working at a railroad. The resulting dorsal-ulnar wrist blow caused disabling pain. Splits and 2 subsequent surgeries failed, including an arthroscopic triangular fibrocartilage complex (TFCC) debridement and thermal ablation.

Preoperative Imaging of Intraneural Ganglion Cysts: A Critical Systematic Analysis of the World Literature.

Background: Advancements in imaging and an understanding of the pathomechanism for intraneural ganglion cyst formation have led to increased awareness and recognition of this lesion. However, the precise role of imaging has been advocated for but not formally evaluated.

Methods: We performed a systematic review of the world literature to study the frequency of imaging used to diagnose intraneural ganglion cysts at different sites and compared trends in identifying joint connections.

Does complete regression of intraneural ganglion cysts occur without surgery?

Purpose: The dynamic nature of intraneural ganglion cysts, including spontaneous expansion and regression, has been described. However, whether these cysts can regress completely in the absence of surgical management has important therapeutic implications. Therefore, we aim to review the literature for cyst regression without surgical intervention.

Clinical and radiographic outcomes of hybrid glenoid fixation with a central porous titanium post: analysis of 713 consecutive shoulders.

Background: Hybrid glenoid component fixation represents an emerging technology in total shoulder arthroplasty (TSA) design. However, there is a paucity of larger-scale studies reporting the outcomes following implantation of these components. This study aimed to determine the outcomes following primary TSA using hybrid glenoid component fixation with a central porous titanium post.

Prevalence of groin pain after primary dual-mobility total hip arthroplasty.

Background: Instability remains a challenging problem following total hip arthroplasty (THA). Dual-mobility (DM) components are used with increasing frequency to mitigate this potential complication. As has been shown with larger metal-on-metal (MoM) THA, the larger size femoral head may pose an increased risk of groin pain.

Clinical Features, Natural History, and Outcomes of Intraneural Perineuriomas: A Systematic Review of the Literature.

Background: Intraneural perineurioma is a rare peripheral nerve sheath tumor characterized by localized proliferation of perineurial cells. The literature consists predominantly of case reports and institutional series, with inconsistent and confusing nomenclature. We present a pooled analysis of all reported cases of intraneural perineurioma in the literature.

High prevalence of cervical myelopathy in patients with idiopathic normal pressure hydrocephalus.

Background: Both idiopathic normal pressure hydrocephalus (iNPH) and cervical myelopathy may result in progressive gait impairment. Some patients who do not respond to shunting despite a positive tap test may have gait dysfunction from cervical myelopathy. The objective of this study was to determine the prevalence of cervical myelopathy in patients with iNPH.

Limb Undergrowth in Intraneural Perineuriomas: An Under-Recognized Association.

Background: Intraneural (IN) perineuriomas are a rare benign hypertrophic nerve tumor, most frequently occurring in young patients. Patients with IN perineurioma have been anecdotally found to have limb undergrowth; however, this has not been systematically evaluated.

Methods: Archived electronic records from 1990 to 2018 from a single institution were reviewed for pathology or radiology reports documenting a diagnosis of IN perineurioma.