Posterior interosseous nerve syndrome caused by a ganglion cyst and its surgical release with intraoperative neurophysiological monitoring: A case report.

RATIONALE: Intraoperative neurophysiological monitoring (IONM) has been utilized not only for the rapid detection of neural insults during surgeries, but also to verify the neurophysiological integrity of nerve lesions in the surgical field. PATIENT CONCERNS: A 32-year-old woman presented with a wrist and finger drop that had lasted about 3 months. DIAGNOSES: The result of the initial electrodiagnostic test was consistent with posterior interosseous nerve (PIN) syndrome. Ultrasonography and magnetic resonance imaging of the proximal forearm showed a cystic mass at the anterolateral aspect of the radial head, which was diagnosed as a ganglion cyst. INTERVENTIONS: Surgical release of the ganglion cyst with IONM was performed. During the surgery, we induced nerve action potentials and compound motor action potentials across the ganglion cyst, which demonstrated neural continuity. OUTCOMES: Three months after the surgery, the patient showed partial recovery of wrist and finger extensor muscle power. An electrodiagnostic test conducted 3 months after the surgery showed reinnervation potentials in PIN-innervated muscles. LESSONS: IONM during peripheral nerve surgeries can support surgical decisions and confirm the location and degree of nerve damage.

Embolization for intractable spontaneous hemarthrosis of the knee joint in the elderly patient: Case report.

RATIONALE: Several case reports about the diagnostic and therapeutic approaches of hemarthrosis after total knee arthroplasty using angiogram have been reported, owing to the probability of bleeding caused by vascular injuries. However, there were only few cases of spontaneous hemarthrosis of the knee joint in the elderly patient that have not undergone total knee arthroplasty that have been previously reported. PATIENTS CONCERNS: An 82-year-old male presented to our outpatient department with acute left knee pain. He had no history of trauma. The patient had under gone several times of therapeutic arthrocentesis for treatment of left knee joint effusion at a local clinic. DIAGNOSIS: Arthroscopic examination was performed at the local clinic and was not able to reveal any focus of intra-articular bleeding. We consulted this case with the department of radiology to angiographically find out abnormalities of the genicular arteries. Angiographs showed hyper vascularity of the superior and inferior lateral genicular artery, and superior medial genicular artery. INTERVENTION: One-step embolization using micro-catheter and 50 to 150 µm gelfoam particles was conducted. The hypervascular findings shown on angiogram were markedly subsided after embolization. OUTCOMES: Until 1 year after embolization, there were no signs of recurrence on outpatient follow-up sessions LESSONS:: Degenerative changes of the genicular arteries may be a cause of spontaneous knee joint hemarthrosis in the elderly patients. Angiographic diagnosis and treatment may be effective for such cases.

Pronation type Galeazzi-equivalent fracture: A rare case report (CARE-compliant).

RATIONALE: Galeazzi fractures are uncommon, and are less common in children than in adults. Galeazzi-equivalent fractures, a variant of the classic Galeazzi fractures, mostly occur in children or adolescents. Galeazzi equivalent fractures may commonly accompany distal radial fractures or injury of the epiphyseal plate of the distal ulna. PATIENT CONCERNS: A 13-year-old man visited our emergency department after stumbling over a rock. Manual reduction and splinting was already done in a nearby medical center. Plain radiographs revealed fractures in the distal radius and fracture of the ulnar epiphyseal plate. DIAGNOSIS: Plain radiographs showed Galeazzi-equivalent fracture. The result of primary closed reduction was not enough and there was still displacement of fracture. INTERVENTIONS: Anatomical reduction of distal radius was fixed with a plate and screws, and K-wires were inserted percutaneously for reduction and fixation of ulnar fracture. OUTCOMES: Complete bone union was achieved and normal range of motion is shown 2 years postoperatively. The patient is able to perform daily activities and sport activities without any signs of ulnar growth arrest. LESSONS: Open reduction is required in patients with malalignment, failure to reduce the DRUJ or maintain its reduction, or older ages which are hard to expect sufficient bone remodeling.

Changes of mediolateral soft tissue gaps in total knee arthroplasty after suturing medial extensor in navigation.

PURPOSE: Aim is to investigate the changes of mediolateral soft tissue gaps in total knee arthroplasty (TKA) after suturing medial extensor. METHODS AND MATERIALS: We compared the differences of medial and lateral gap values that were shown by the computer navigation at 0°, 45°, 90°, and 120° knee flexion during patella in situ and during patella repaired by a towel clip on two constant sites. Fifty consecutive knees (43 patients) scheduled for TKA due to varus knee osteoarthritis, from February 2017 to May 2017, were enrolled in this prospective study. RESULTS: The medial gaps with patella repaired were significantly lower ( p < 0.05) than the medial gaps with patella in situ at 45°, 90°, and 120° knee flexion. Differences in the medial gap were largest at 90, with the difference of 0.87 mm. Twenty-four of 50 cases (48%) showed medial gap differences of 1 mm or over, and 13 of 50 cases (26%) showed medial gap differences of 2 mm or over. The variation in the medial gap at 90° following patellar repair showed significant association (correlation coefficient = 0.78, p = 0.001) with the difference between medial and lateral gaps (medial gap - lateral gap) at 90° of patella in situ. At 90° knee flexion, when the medial and lateral gap difference in patella in situ was 1 mm or less, 73.5% (25/34) of the cases showed variation in the medial gap of less than 1 mm after patellar repair. CONCLUSION: During TKA, while measuring the medial gap with patella in situ, overestimation might occur, especially in the position of knee flexion. Thus, reevaluation using towel clips should be considered when the medial and lateral gap difference is 1 mm or larger when patella in situ during evaluation of the medial and lateral gaps at 90° knee flexion.

The Effect of Positive Medial Cortical Support in Reduction of Pertrochanteric Fractures with Posteromedial Wall Defect Using a Dynamic Hip Screw.

BACKGROUND: We evaluated the radiological and clinical results of reduction using a dynamic hip screw according to the grade of medial cortical support in patients with AO Foundation and Orthopaedic Trauma Association (AO/OTA) classification type 31-A2 pertrochanteric fractures. METHODS: We enrolled 100 patients with AO/OTA type 31-A2 fractures with displaced lesser trochanter fragments (length of the cortical area longer than 20 mm on the pelvis anteroposterior view). Patients with positive medial cortical support were assigned to group 1 (n = 28); neutral medial cortical support, group 2 (n = 42); and negative medial cortical support, group 3 (n = 30). Radiological evaluation was done by measuring the change in the femoral neck-shaft angle and sliding distance of the lag screw. Clinical outcomes of each group were compared by means of the walking ability score proposed by Ceder. RESULTS: Group 1 showed significantly less changes in the femoral neck-shaft angle and shorter sliding distance than groups 2 and 3. Group 2 showed significantly less changes in the femoral neck-shaft angle and shorter sliding distance than group 3. Group 1 showed significantly higher walking ability scores than group 3 (p = 0.00). The use of trochanter stabilizing plates or fixation using wires for posteromedial wall defect resulted in no significant changes in terms of the femoral neck-shaft angle or sliding distance. CONCLUSIONS: In the treatment of pertrochanteric fractures accompanied by posteromedial wall defect using a dynamic hip screw, reduction with negative cortical support should be avoided.

Results of Primary Total Hip Arthroplasty Using 36 mm Femoral Heads on 1st Generation Highly Cross Linked Polyethylene in Patients 50 Years and Less with Minimum Five Year Follow-up.

PURPOSE: We evaluated the clinical and radiographic midterm results of primary total hip arthroplasty (THA) using a 36 mm diameter femoral head on 1st generation highly cross-linked polyethylene (HXLPE) in patients 50 years and less with minimum five year follow-up. MATERIALS AND METHODS: We retrospectively reviewed 31 patients (41 hips) aged 50 years and less underwent primary THA with a 36 mm diameter femoral head on HXLPE between 2004 and 2010. Clinical follow-ups included specific measurements like modified Harris hip scores (HHS) and Merle d'Aubigne and Postel score. For radiologic evaluations, together with position of acetabular cup at six weeks later of postoperation, we separately calculated the penentrations of femoral head into polyethylene liners during postoperation and one year later check-ups, and during one year later check-ups and final check-ups. RESULTS: There were no major complications except for one case of dislocation. Average modified HHS at final follow-up was 88 (81-98), and Merle d'Aubigne and Postel scores were more than 15. Mean acetabular cup inclination and anteversion were 45.81°(36.33°-54.91°) and 13.26°(6.72°-27.71°), respectively. Average femoral head penetration of steady-state wear rate determined using radiographs taken at one-year postoperatively and at latest follow-up was 0.042±0.001 mm/year. CONCLUSION: Based on minimum 5 years clinical results, we think 36 mm metal head coupling with HXLPE as the good alternate articulation surface when planning THA for patients aged 50 years and less.

A Liner Breakage in Total Hip Arthroplasty after Using 1st Generation Highly Cross Linked Polyethylene Mated against 36-mm Metal Head: A Case Report.

It has been known the highly cross linked polyethylene (HXLPE) has an advantage of improved wear rate. However, the alteration in mechanical properties such as decreased tensile yield and fatigue strength make concerns about fragility of HXLPE. We experienced a case of HXLPE breakage. But, this case of liner breakage happened although patient belonged to normal BMI and proper acetabular cup position so called "safe zone" on radiographs. So, we report this case with reference review.