Citations

Purpose To analyze the complications of arthroscopic heterotopic ossification (HO) excision and compare them with those of open removal of HO or a combined open‐arthroscopic approach. Methods We performed a retrospective review of elbow HO removal cases performed by a single surgeon from 1997 to 2014. In all cases studied, the intention was to restore range of motion owing to the presence of HO causing functional impairment. The arthroscopic, open, and combined treatment groups were compared. Results The study cohort consisted of 223 surgical procedures performed on 213 elbows in 211 patients. Fifty major complications occurred in 46 cases (21%): 17 hematomas (8%) treated by irrigation and debridement, 8 cases of HO requiring reoperation (4%), 7 deep infections (3%), 4 contractures (2%), 3 cases of delayed‐onset ulnar neuritis (1%), 2 cases of distal humeral avascular necrosis (1%), 2 tendon ruptures (1%), 2 cases of instability requiring reconstruction (1%), 2 postoperative fractures (1%), 1 intraoperative fracture (<0.5%), 1 case of worsening of pre‐existing neuropathic pain (<0.5%), and 1 permanent partial posterior interosseous nerve injury (<0.5%). Of these 46 cases, the major complications occurred in 6 of the 41 (15%) performed arthroscopically, in 36 of the 158 (23%) performed open and in 4 of the 21 (17%) with combined (i.e. open + arthroscopic) HO removal. Preventive strategies, introduced to prevent hematomas and delayed‐onset ulnar neuritis, reduced the rate of major complications from 35% during the period from 1997 to 2005 to 10% during the period from 2006 to 2014 ( P < .0001). Moreover, the rate of reoperations was reduced from 34% to 10% in the same periods ( P < .0001). Minor complications occurred in 36 cases (16%), including 17 cases of transient nerve palsy, 9 cases of superficial infection or delayed wound healing, 6 cases of mild instability, and 4 cases of hematoma resolved by aspiration. Conclusions The use of arthroscopy—or a combination of arthroscopic and open techniques—to remove HO around the elbow by a surgeon skilled in both arthroscopic and open elbow surgery does not increase the risk of major complications or need for reoperation compared with traditional open surgery. Preventive strategies, such as avoiding raising skin flaps by using multiple separate incisions for open and prophylactic ulnar nerve decompression in arthroscopic cases, were developed during the study period. These strategies were monitored prospectively and found to be effective in preventing two‐thirds of the major complications needing reoperation with both open and arthroscopic HO removal. Level of Evidence Level III, retrospective comparative study of prospectively collected data.

Objective:To ascertain long-term hearing outcomes in patients with serviceable hearing following microsurgical resection of sporadic vestibular schwannoma (VS).Study Design:Retrospective cohort.Setting:Tertiary academic referral center.Patients:Forty-three adult subjects with unilateral sporadic VS who had serviceable hearing (American Academy of Otolaryngology–Head and Neck Surgery [AAO-HNS] class A or B) on initial postoperative audiogram following microsurgical resection between 2003 and 2016 with a minimum of two postoperative audiograms available for review.Intervention:Surgical treatment with a retrosigmoid or middle cranial fossa approach.Main Outcome Measure:Rate of maintaining serviceable hearing, as estimated using the Kaplan–Meier method, in accordance with the 1995 and 2012 AAO-HNS guidelines on reporting hearing outcomes.Results:The median immediate postoperative pure-tone average (PTA) and word recognition score (WRS) were 31 dB and 95%, respectively. At last follow-up, the median PTA was 38 dB with a median change of 5 dB from initial postoperative audiogram, and the median WRS was 90% with a median change of 0% from initial postoperative audiogram. Eight patients developed non-serviceable hearing at a median of 4.1 years following microsurgical resection (interquartile range, 2.9–7.0). The median duration of hearing follow-up for the 35 patients who maintained serviceable hearing was 3.1 years (interquartile range, 2.2–7.5). Tumor control was achieved in 41 (95%) patients. The rate of maintaining serviceable hearing at 5 years was 81%.Conclusion:Microsurgical resection provides excellent tumor control and durable long-term hearing in those with AAO-HNS class A or B hearing postoperatively. The paradigm of proactive microsurgical resection—when the tumor is small and hearing is good—hinges on the surgeon's ability to preserve residual hearing in a very high percentage of cases at or near preoperative hearing levels to maintain an advantage over conservative observation with regard to long-term hearing preservation.

Background Over-lengthening of the radial neck has been shown to affect ulnohumeral kinematics and has been proposed to affect radiocapitellar pressures. We hypothesized that an incremental increase in radial neck height increases the capitellar contact pressure and reduces the coronoid contact pressure. Knowledge of the effects of over-lengthening is clinically important in preventing pain and degenerative changes due to overstuffing. Methods Six human cadaveric elbows were prepared on a custom-designed apparatus simulating muscle loads and passive flexion from 0° to 90° under gravity valgus torque while measuring joint contact pressures in this biomechanical study. Each elbow was tested sequentially starting with the intact specimen followed by insertion of a radial head prosthesis with 0, +2, and +4 mm of radial neck height, respectively. Results Capitellar mean contact pressures significantly increased after insertion of +2 and +4 mm radial head prostheses (p < 0.03). The capitellar mean contact pressure with a 0 mm radial head prosthesis was 97 KPa. Insertion of +2 mm and +4 mm radial heads increased mean contact pressures to 391 KPa (p = 0.001) and 619 KPa (p = 0.001), respectively, with 90° of elbow flexion. Discussion Increasing radial prosthesis height by 2 mm significantly increases capitellar contact pressures and reduces coronoid contact pressures.

Abstract Introduction Neurosurgical anatomy is traditionally taught via anatomic and operative atlases; however, these resources present the skull base using views that emphasize three-dimensional (3D) relationships rather than operative perspectives, and are frequently written above a typical resident's understanding. Our objective is to describe, step-by-step, a retrosigmoid approach dissection, in a way that is educationally valuable for trainees at numerous levels. Methods Six sides of three formalin-fixed latex-injected specimens were dissected under microscopic magnification. A retrosigmoid was performed by each of three neurosurgery residents, under supervision by the senior authors (C.L.W.D. and M.J.L.) and a graduated skull base fellow, neurosurgeon, and neuroanatomist (M.P.C.). Dissections were supplemented with representative case applications. Results The retrosigmoid craniotomy (aka lateral suboccipital approach) affords excellent access to cranial nerve (CN) IV to XII, with corresponding applicability to numerous posterior fossa operations. Key steps include positioning and skin incision, scalp and muscle flaps, burr hole and parasigmoid trough, craniotomy flap elevation, initial durotomy and deep cistern access, completion durotomy, and final exposure. Conclusion The retrosigmoid craniotomy is a workhorse skull base exposure, particularly for lesions located predominantly in the cerebellopontine angle. Operatively oriented neuroanatomy dissections provide trainees with a critical foundation for learning this fundamental skull base technique. We outline a comprehensive approach for neurosurgery residents to develop their familiarity with the retrosigmoid craniotomy in the cadaver laboratory in a way that simultaneously informs rapid learning in the operating room, and an understanding of its potential for wide clinical application to skull base diseases.

Objective: To report the use of multi-frequency intra-cochlear electrocochleography (ECOG) in monitoring and optimizing electrode placement during cochlear implant surgery. An acoustic pure tone complex comprising of 250, 500, 1000, and 2000 Hz was used to elicit ECOG, or more specifically cochlear microphonics (CMs), responses from various locations in the cochlea. The most apical cochlear implant electrode was used as the recording electrode. Study Design: Clinical capsule report. Setting: Tertiary academic referral center. Results: ECOG measurements were performed during cochlear implant surgery in an adult patient with significant residual acoustic hearing. The 500, 1000, and 2000 Hz CM tracings from the most apical electrode showed an amplitude peak at three different instances during the early phase of cochlear implant electrode insertion. These results are consistent with the tonotopic organization of the cochlea. During final electrode placement a slight advancement of the electrode array resulted in a correlated decrease in 250, 500, and/or 1000 Hz CM amplitude. The electrode array was retracted and repositioned which resulted in a recovery of CM amplitude. Intraoperative CM thresholds revealed a correlation of r = 0.87 with preoperative audiometric thresholds. Conclusion: We present a report on simultaneous multi-frequency ECOG monitoring during cochlear implant surgery. Multi-frequency ECOG can be used to differentiate between electrode trauma and the advancement of the apical electrode beyond the CM source in the cochlea.

Objective: To date, prediction models for estimating risk of acquiring non-serviceable hearing in subjects with observed vestibular schwannoma (VS) have evaluated outcomes primarily based on features at initial diagnosis. Herein, we evaluate the association of rate of hearing decline during the initial period of observation with time to non-serviceable hearing. If significant, rate of hearing decline may inform decision making after an introductory period of observation. Setting: Two tertiary care centers. Patients: VS patients with serviceable hearing who underwent at least three audiograms and two magnetic resonance imaging (MRI) studies before intervention or being lost to follow-up. The rate of change in pure-tone average (PTA) and word recognition score (WRS) was calculated as the score from the second audiogram minus the score from the first audiogram, divided by the duration in months between the two. Main Outcome Measure(s): Serviceable hearing, defined as PTA ≤50 dB HL and WRS ≥50%. Results: Among 266 patients meeting inclusion criteria, 52 developed non-serviceable hearing at last follow-up. Kaplan–Meier estimated rates of maintaining serviceable hearing (95% CI; number still at risk) at 1, 3, 5, 7, and 10 years were 97% (95–100; 206), 78% (72–85; 98), 68% (60–77; 39), 60% (50–73; 17), and 44% (29–67; 2), respectively. In a univariable setting, each 1 dB increase per month in the rate of initial PTA change was associated with a 96% increased likelihood of acquiring non-serviceable hearing (hazard ratio [HR] 1.96; 95% CI 1.44–2.68; p < 0.001). Each 1% increase per month in the rate of initial WRS change was associated with a decreased likelihood of acquiring non-serviceable hearing (hazard ratio [HR] 0.79; 95% confidence interval [CI] 0.66–0.94; p = 0.009). After multivariable adjustment, both rate of PTA change (HR 2.42; 95% CI 1.72–3.41; p < 0.001) and rate of WRS change (HR 0.81; 95% CI 0.67–0.99; p = 0.043) remained statistically significantly associated with time to non-serviceable hearing. Conclusion: Rate of early PTA and WRS decline during the initial period of observation are significantly associated with time to development of non-serviceable hearing. This information may facilitate accurate patient counseling and inform decision-making regarding prospective disease management.

Abstract The pursuit of rationale, targeted therapies relies on a detailed understanding of the mechanisms that subvert normal growth control and lead to development of Multiple Myeloma (MM). To further define the mechanistic steps that contribute to MM pathogenesis, we examined mRNA expression profiles of CD138+ plasma cells obtained from normal, Monoclonal Gammopathy of Unknown Significance (MGUS), and MM patient samples. Using genomic results in combination with molecular and cellular-based assays, we demonstrate a critical role for UBC9 and the sumoylation pathway in myeloma cell growth and survival. Notably, Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) demonstrated a ten-fold induction in UBC9; a gene that encodes the sole Sumo-conjugating enzyme in human cells. We demonstrated an elevation of UBC9 in both MM primary patient cells and in a number of patient-derived MM cell lines. In addition, a number of other sumoylation pathway components were induced in primary MM cells at the gene and protein level relative to normal plasma cells. We believe that induction of UBC9 is an early genetic event in the pathogenesis of MM since the induction was observed at the gene and protein level in plasma cells from patients with MGUS. Importantly, UBC9 induction was functionally significant since a different pattern of sumoylation was observed in total cell lysate from MM patient plasma cells relative to that of normal plasma cells. Furthermore, overexpresion of a mutant form of UBC9 deficient in Sumo-conjugating activity increased the sensitivity of plasma cells to apoptosis by chemotherapeutic agents and these cells were impaired in other essential functions that included cellular proliferation, DNA synthesis, resistance to apoptosis and adhesion to bone marrow stroma. Immunoblotting of MM patient cell lysates also demonstrated a similar induction of the UBC9 gene product (Ubc9) as well as induction of the Sumo ligases Nse2 and PIAS1. These studies identify UBC9 as a target upregulated early in the pathogenesis of MM and indicate a critical role for sumoylation in disrupting the controls that govern normal plasma cell growth. To further develop prognostically relevant molecular signatures and classifications of MM subtypes, we analyzed the survival outcome of patients that expressed induced levels of UBC9, as well as other sumoylation components, and demonstrate significantly reduced survival of such patients following current treatment modalities. The results provide evidence for critical role of UBC9 and sumoylation in MM pathogenesis. Furthermore, sumoylation pattern may serve as a therapeutic target in MM, help stratify clinical management and provide a framework for the identification of sumoylation pathway targets that govern MM cell growth and progression.

OBJECTIVE Tumor-associated macrophages (TAMs) have been implicated as pathologic actors in phenotypically aggressive vestibular schwannoma (VS), potentially mediated via programmed death-ligand 1 (PD-L1). The authors hypothesized that PD-L1 is a key regulator of the VS immune microenvironment. METHODS Forty-six consecutive, radiation-naïve, sporadic VSs that were subtotally resected at primary surgery were assessed via immunohistochemical analysis, including analysis of CD163 and PD-L1 expression. Pathologic data were correlated with clinical endpoints, including tumor control, facial nerve function, and complications. RESULTS Baseline parameters were equivalent between stable and progressive post–subtotal resection (STR) VS. CD163 percent positivity and M2 index were significantly increased among tumors that remained stable (34% vs 21%, p = 0.02; 1.13 vs 0.99, p = 0.0008), as well as patients with favorable House-Brackmann grade I or II facial nerve function (31% vs 13%, p = 0.04; 1.11 vs 0.97, p = 0.05). PD-L1 percent positivity was significantly associated with tumor progression (1% vs 11%, p = 0.01) and unfavorable House-Brackmann grade III–VI facial nerve function (1% vs 38%, p = 0.02). On multivariate analysis, PD-L1 was independently significant in all models (likelihood ratio 4.4, p = 0.04), while CD163 was dependent in all iterations. CONCLUSIONS In contrast to prior reports, in this study, the authors observed significantly increased levels of M1, CD163 + TAMs in association with VS that progressed after STR. Progressive tumors are characterized by increased PD-L1, potentially highlighting a mechanism of immune evasion that results in TAM deactivation, tumor growth, and further infiltration of anti-tumor immune cells. Targeting PD-1/PD-L1 may offer therapeutic promise, particularly in the setting of disease control after STR.

Background To determine if self-taken photographs (“selfies”), performed independently after instruction by video or illustrated handout, would be an accurate and reliable tool for capturing elbow range of motion in patients with elbow contractures. Methods Fifty patients presenting with elbow contractures participated in the study. After completion of the selfie, the senior author clinically measured flexion and extension with a goniometer. The angles from the photographs were measured and analyzed. Results The agreement between goniometer and “selfie” measurements correlated closely (R 2 = 0.98) and agreement was excellent in both extension and in flexion with intra-class correlation coefficients of 0.95 (95% CI 0.92 to 0.97) in extension with a mean difference of 2° (95% CI −3° to 7°), and 0.93 (95% CI 0.89 to 0.96) in flexion with a mean difference of 4° (95% CI 0° to 8°). Systematic errors were low in extension, 0° (95% CI, ±11°) and in flexion −3° (95% CI, ±10°). Six patients demonstrated ≥10° difference between clinical and selfie measurements. Ability to take a usable selfie was inversely correlated with age (R 2 = 0.97). Discussion Self-taken flexion–extension photographs are a reliable and accurate tool for measuring elbow range of motion. Errors in the selfie technique are well tolerated and appear to have a negligible effect upon measurements of motion. This important parameter of elbow function can therefore be obtained outside a normal clinic visit, thereby improving frequency of follow-up assessments (and minimizing loss to follow-up) necessary for quality control and research.

Objective: The etiology of sensorineural hearing loss (SNHL) in patients with jugular paraganglioma (JP) whose tumors lack inner ear fistulae or vestibulocochlear nerve involvement is unknown. Recent literature has proposed that occlusion of the inferior cochlear vein may be causative. Herein, we assess the association between radiologic involvement of the cochlear aqueduct (CA) and the development of SNHL. Study Design: Blinded, retrospective review of imaging and audiometry. Setting: Tertiary center. Patients: Adults with JP. Intervention(s): None. Main Outcome Measures: Asymmetric SNHL was assessed continuously as the difference in bone conduction pure-tone average (BCPTA) between ears and as a categorical variable (≥15 dB difference at two consecutive frequencies, or a difference in speech discrimination score of ≥15%). Involvement of the CA was considered present if there was evidence of medial T2 fluid signal loss, contrast enhancement, or bony erosion/expansion. Results: Of 30 patients meeting inclusion criteria, 15 (50%) had asymmetric SNHL. CA involvement was observed in 87% of patients with asymmetric SNHL compared with 13% in those with symmetric hearing (p = 0.0001). Univariate analysis demonstrated that age, sex, and tumor volume were not associated with asymmetric SNHL. The median difference in BCPTA between ears in patients with CA involvement was 21.3 dB HL compared to 1.2 dB HL in those without CA involvement (p < 0.0001). Regression analysis demonstrates that enhancement within the CA is associated with a BCPTA difference of 19.4 dB HL (p = 0.0006). Conclusions: Cochlear aqueduct involvement by JP is associated with SNHL in the absence of inner ear fistula, vestibulocochlear nerve involvement, or brainstem compression. Correlation with operative findings or histopathologic evidence of tumor involvement may validate this intriguing imaging finding.