Three-dimensional analysis of baseplate screw penetration in reverse total shoulder arthroplasty: risk of iatrogenic suprascapular neuropathy by screw violation.

BACKGROUND: Baseplate screws have been suggested to be a possible cause of suprascapular neuropathy after reverse total shoulder arthroplasty (RTSA). Three-dimensional analyses of screw penetration and confirmation of its clinical impacts are relevant. The study aims to investigate the association between screw penetration and the clinical outcomes. MATERIALS AND METHODS: Eighty-two patients who underwent RTSA for a massive rotator cuff tear, cuff tear arthropathy, or osteoarthritis with rotator cuff tear were retrospectively enrolled. They were followed up for a minimum of 12 months, and all underwent computed tomography at 1 year postoperatively. The lengths of the superior and posterior baseplate screws were documented. Postoperative computed tomography images were subjected to 3-dimensional analysis to determine whether superior or posterior screws penetrated the glenoid vault and the location to which they penetrated, and screw-to-nerve distances were measured to estimate risks of screw nerve violation and iatrogenic suprascapular neuropathy. Patients with any screw <5 mm from the suprascapular nerve were deemed to have a high risk. Clinical outcomes (functional scores, ranges of motion, and isometric strengths) of patients in the high- and lower-risk groups were compared. RESULTS: The mean lengths of the superior and posterior screws were 28 ± 4 mm and 18 ± 3 mm, respectively. Penetration was detected for 13% of superior screws and 64% of posterior screws. Sixty-three percent of penetrating superior screws and 5% of penetrating posterior screws were <5 mm from the suprascapular nerve, and therefore, 12% of patients who received RTSA were assessed to have a high risk of iatrogenic suprascapular neuropathy. However, no significant difference was detected in clinical outcomes between the high- and lower-risk patients after a mean follow-up period of 20 months. CONCLUSION: Twelve percent of patients who received RTSA were assessed to be at high risk of iatrogenic suprascapular neuropathy by baseplate screw penetration. However, the clinical outcomes of RTSA at a minimum follow-up of 1 year were similar in the high- and lower-risk groups.

Prevalence and Clinical Impact of Acromial Cupping after Arthroscopic Rotator Cuff Repair: Does Acromioplasty Matter?

BACKGROUND: Although the effectiveness of acromioplasty is controversial, it is commonly performed during rotator cuff repair to reduce external impingement. During follow-up, osteolysis under the acromion (acromial cupping) could be observed. However, this phenomenon has been rarely addressed in the literature. The purpose of this study was to compare the prevalence and severity of acromial cupping after rotator cuff repair depending on the concomitant performance of acromioplasty and evaluate the influence of acromial cupping on clinical and radiological outcome. METHODS: This is a retrospective study involving patients who underwent arthroscopic rotator cuff repair for small-to-large full-thickness rotator cuff tears from October 2015 to March 2019 and clinical follow-up and magnetic resonance imaging at least 1 year postoperatively. A total of 110 patients were enrolled and divided into two groups depending on whether acromioplasty had been performed (group A) or not (group N). The prevalence of acromial cupping was evaluated in each group. In addition, we stratified patients according to the severity of acromial cupping to investigate its influence on healing and functional scores (visual analog scale [VAS], American Shoulder and Elbow Surgeons [ASES] score, simple shoulder test [SST], and Constant-Murley score). RESULTS: There were 85 patients in group A and 25 patients in group N. The prevalence of acromial cupping and acromial cysts was as follows: 36.4% (40 patients) and 6.4% (7 patients), respectively, in the total subjects; 43.5% (37/85) and 5.9% (5/85), respectively, in group A; and 12.0% (3/25) and 8.0% (2/25), respectively, in group N. The prevalence of acromial cupping was significantly different between the two groups (p = 0.012). However, functional outcomes were not significantly different between groups stratified by the severity of acromial cupping (VAS, p = 0.464; ASES score, p = 0.902; SST, p = 0.816; and Constant-Murley score, p = 0.117). The difference in healing rate was statistically insignificant between groups (p = 0.726). CONCLUSIONS: The incidence and severity of acromial cupping were significantly greater in patients who underwent rotator cuff repair with acromioplasty. It was a relatively common phenomenon, especially after acromioplasty. However, neither the existence nor the severity of acromial cupping affected functional outcomes or healing.

Acute airway obstruction due to postoperative retropharyngeal hematoma after anterior cervical fusion: a retrospective analysis.

BACKGROUND: Acute airway obstruction (AAO) after anterior cervical fusion (ACF) can be caused by postoperative retropharyngeal hematoma, which requires urgent recognition and treatment. However, the causes, evaluation, and appropriate treatment of this complication are not clearly defined. The purpose of this retrospective review of a prospective database was to investigate etiologic factors related to the development of AAO due to postoperative hematoma after ACF and formulate appropriate prevention and treatment guidelines. METHODS: Cervical spinal cases treated at our academic institutions from 1998 to 2013 were evaluated. Demographic data, including factors related to hemorrhagic tendency, and operative data were analyzed. Patients who developed a hematoma were compared with those who did not to identify risk factors. Cases complicated by hematoma were reviewed, and times until development of hematoma and surgical evacuation were determined. Degrees of airway compromise and patient behavior were classified and evaluated. Treatment was selected according to the patient's status. RESULTS: Among 785 ACF procedures performed, there were nine cases (1.15%) of AAO. None of these nine patients had preoperative risk factors. In six patients (67%), the hematoma occurred within 24 h, whereas three patients (33%) presented with hematoma at a median of 72 h postoperatively. Four of the nine patients with AAO underwent evacuation of the hematoma. Two patients with inspiratory stridor, anterior neck swelling, and facial edema progressed to respiratory distress and their hematomas were removed by surgery, during which, sustained superficial venous bleeding was confirmed. Intubation was attempted several times in one patient with cyanosis, but is unsuccessful; cricothyroidotomy was performed in this patient and pumping in the small muscular arterial branches was confirmed in the operating room. All of the patients recovered without any complications. CONCLUSIONS: With rapid recognition and appropriate treatment, there were no long-term complications caused by postoperative hematoma. There were no specific preoperative risk factors for hematoma. Systematic evaluation and appropriate management can be helpful for preventing serious complications after development of a postoperative hematoma.

Effect of RNA Interference-Mediated Suppression of p75 on the Viability of Rat Notochordal Cells.

STUDY DESIGN: In vitro cell culture model. PURPOSE: To investigate the effects of RNA interference (RNAi) on p75 expression and viability of rat notochordal cells treated with serum deprivation. OVERVIEW OF LITERATURE: RNAi enables the inhibition of specific genes by sequence-specific gene silencing using a double-stranded RNA. METHODS: Notochordal cells were isolated, cultured, and placed in 10% (control) or 0% (apoptosis-promoting) fetal bovine serum (FBS) for 48 hours. The expression of p75, apoptosis, and cell proliferation were determined. To suppress p75 expression, a small interfering RNA (siRNA) was synthesized against p75 (p75 siRNA) and transfected into cells. The suppression of p75 mRNA expression was investigated using the reverse transcription-polymerase chain reaction. The degree of p75 suppression was semiquantitatively analyzed using densitometry. The effect of p75 siRNA on apoptosis and proliferation of cells was determined. Solutions of an unrelated siRNA and transfection agent alone served as controls. RESULTS: Serum deprivation significantly increased apoptosis by 40.3%, decreased proliferation of notochordal cells by 45.3% (both, p<0.001), and upregulated p75 expression. The p75 siRNA suppressed p75 expression in cells cultured in 0% FBS. The rate of suppression by p75 siRNA of p75 mRNA was 72.9% (p<0.001). Suppression of p75 expression by p75 siRNA inhibited apoptosis by 7% and increased proliferation by 14% in cells cultured in 0% FBS (both, p<0.05). CONCLUSIONS: siRNA-mediated suppression of p75 inhibited apoptosis and increased proliferation of notochordal cells under conditions of serum deprivation, suggesting that RNAi might serve as a novel therapeutic approach for disc degeneration caused by insufficient viability of disc cells through the suppression of the expression of harmful genes.

Revision surgery for curve progression after implant removal following posterior fusion only at a young age in the treatment of congenital scoliosis: A case report.

RATIONALE: Congenital scoliosis due to a hemivertebra creates a wedge-shaped deformity, which progresses and causes severe spinal deformities as an individual grows. The treatment of congenital scoliosis focuses on early diagnosis and appropriate surgical management before the development of severe deformity. PATIENT CONCERNS: We report the case of a 4-year-old male child with a left thoracolumbar scoliosis of 27° (T10-T12) due to a T11 hemivertebra who was treated by posterior fusion and pedicle screw fixation at the age of 4 years. The implant was removed due to pain secondary to implant prominence after 4 years without definitive revision surgery, which led to significant progression of the scoliosis, to 50°. The indication for posterior vertebral column resection (PVCR) is a congenital spinal deformity with a curve magnitude greater than 30° with fast progression. This includes documented progression of the curve by more than 5° in a 6- month period, failure of conservative treatment, or both. OUTCOMES: The patient underwent PVCR of the T11 hemivertebra. Nine years after the revision surgery with PVCR, the patient showed satisfactory results and his spine was well balanced. LESSONS: This case shows that removal of an implant that was not the only cause of curve progression at a young age may lead to progression of scoliosis and, therefore, should be avoided unless it is absolutely necessary. CONCLUSION: Congenital scoliosis due to a hemivertebra at a young age could be treated by hemivertebra resection or anterior and posterior epiphysiodesis as definitive surgical treatment. The patient was eventually treated with PVCR, which achieved satisfactory correction without curve progression in a long-term follow-up.