Masahiro Shirahama

Stabilization of an acetabular fracture with cables for acute total hip arthroplasty.

A critical stage of total hip arthroplasty for an acute acetabular fracture where extensive comminution, impaction, and osteopenia thwart the application of conventional open or closed methods, especially in the elderly, is stable fixation of the acetabulum. The use of 2-mm braided cables permits effective immobilization of the fracture for use in conjunction with a hybrid arthroplasty. The method is consistent with the use of a conventional arthroplastic incision and is suitable for other applications including the fixation of periprosthetic fractures, bulk allografts, and conventional acetabular fractures.

Risk factors for shoulder re-dislocation after arthroscopic Bankart repair

BackgroundRecent studies have shown effective clinical results after arthroscopic Bankart repair (ABR) but have shown several risk factors for re-dislocation after surgery. We evaluated whether patients are at a risk for re-dislocation during the first year after ABR, examined the recurrence rate after ABR, and sought to identify new risk factors.MethodsWe performed ABR using bioabsorbable suture anchors in 102 consecutive shoulders (100 patients) with traumatic anterior shoulder instability. Average patient age and follow-up period was 25.7 (range, 14–40) years and 67.5 (range, 24.5–120) months, respectively. We evaluated re-dislocation after ABR using patient telephone interviews (follow-up rate, 100%) and correlated re-dislocation with several risk factors.ResultsRe-dislocation after ABR occurred in nine shoulders (8.8%), of which seven sustained re-injuries within the first year with the arm elevated at 90° and externally rotated at 90°. Of the remaining 93 shoulders without re-dislocation, 8 had re-injury under the same conditions within the first year. Thus, re-injury within the first year was a risk for re-dislocation after ABR (P < 0.001, chi-squared test). Using multivariate analysis, large Hill-Sachs lesions (odds ratio, 6.77, 95% CI, 1.24–53.6) and <4 suture anchors (odds ratio, 9.86, 95% CI, 2.00–76.4) were significant risk factors for re-dislocation after ABR.ConclusionsThe recurrence rate after ABR is not associated with the time elapsed and that repair strategies should augment the large humeral bone defect and use >3 anchors during ABR.

Effects of corticosteroids and hyaluronic acid on torn rotator cuff tendons in vitro and in rats.

Corticosteroids (CS) or hyaluronic acid (HA) is used in subacromial injection for the conservative treatment of rotator cuff tears (RCT); this study addresses the question of how CS and HA affect the tendon tissue and fibroblasts in vitro and in rats. Cell proliferation assays were performed in human tendon fibroblasts from RCT. Rats underwent surgery to create RCT, and the surgical sites were injected with CS or HA. The rotator cuff tendons were subjected to biomechanical testing, microscopic and immunohistochemical analysis of proliferating cell nuclear antigen (PCNA), and ultrastructural analysis. Cell proliferation was significantly decreased with CS in vitro (p < 0.05). Maximal load of CS‐treated tendons was significantly decreased compared with that of HA‐treated tendons (p < 0.05), as well as PCNA+ cells at 2 weeks (p < 0.05). Ultrastructural observations of the CS‐treated rats detected apoptosis of tendon fibroblasts 24 h after surgery. Histological and biomechanical data 4 weeks after surgery were not significant among the three groups. Unlike HA, CS caused cell death, and inhibition of the proliferation of tendon fibroblasts, leading to a delay of tendon healing involved and a subsequent decrease of biomechanical strength at the surgical site.

Infective Endocarditis Presenting as Right Shoulder Pain: A Case Report

Although cases of referred shoulder pain due to ischemic heart disease have been well documented, to our knowledge no reports on infective endocarditis accompanied by referred right shoulder pain have been published. A 43-year-old Japanese man presented with severe right shoulder pain and a body temperature of 38°C.Blood tests showed inflammation and liver dysfunction, although magnetic resonance imaging did not indicate septic shoulder arthritis. However, contrast-enhanced computed tomography showed renal, splenic, and hepatic infarctions. Moreover, a labile vegetation was detected on an echocardiogram. The patient was diagnosed with infective endocarditis and antibiotics were administered intravenously. Infective endocarditis is a serious condition that can result in complications if it is not diagnosed and treated at an early stage. Therefore, in cases with referred shoulder pain, physicians should carefully consider the presence of internal diseases that may cause this condition, as in the present case.

Clinical outcomes of the Cadenat procedure in the treatment of acromioclavicular joint dislocations.

We report our clinical experience using the modified Cadenat method to treat acromioclavicular joint dislocation, and discuss the usefulness of this method. This study examined 6 shoulders in 6 patients (5 males, 1 female) who were diagnosed with acromioclavicular joint dislocation and treated with the modified Cadenat method at our hospital. Average age at onset was 49.3 years (26-78 years), average time interval from injury until surgery was 263.8 days (10 to 1100 days), and the average follow-up period was 21.7 months (12 to 42 months). Post-operative assessment was performed using plain radiographs to determine shoulder joint dislocation rate and Japanese Orthopaedic Association (JOA) score. The average post-operative JOA score was 94.1 points (91 to 100 points). The acromioclavicular joint dislocation rate improved from 148.7% (72 to 236%) before surgery to 28.6% (0 to 60%) after surgery. Conservative treatment has been reported to achieve good outcomes in acromioclavicular joint dislocations. However, many patients also experience chronic pain or a sensation of fatigue upon putting the extremity in an elevated posture, and therefore ensuring the stability of the acromioclavicular joint is crucial for highly active patients. In this study, we treated acromioclavicular joint dislocations by the modified Cadenat method, and were able to achieve favorable outcomes.