The study of 2-dimensional computed tomography scans of the glenoid anatomy in relation to reverse shoulder arthroplasty in the Southern Chinese population.

BACKGROUND: Reverse shoulder arthroplasty is becoming an increasingly common surgical procedure in Hong Kong, as well as in many other countries worldwide. The aim of this study is to describe the glenoid anatomy in the Southern Chinese population. We are interested to know whether commercially available glenoid implants are suitable for this population and whether there are any steps or precautions we can take during surgery to optimize the clinical outcome for these patients. METHOD: A total of 244 shoulders of Southern Chinese patients were analyzed using 2-dimensional computed tomography, formatted to align along the scapular axis. The anatomic parameters analyzed included the shape, axial configuration, maximum width, maximum height, version, and presence of bone defect. RESULTS: In our study, 76.6% of glenoids were pear-shaped, 23.0% were elliptical, and only 0.4% were inverted pear in shape. Of all glenoids, 95.1% of glenoids had posterior-prominent axial configuration, whereas 4.9% had neutral axial configuration. The mean maximum glenoid height for both genders was 33.8 mm, whereas the mean maximum glenoid height was 32.2 mm for women and 36.6 mm for men. The mean maximum glenoid width for both genders was 25.8 mm, whereas the mean maximum glenoid width was 24.8 mm for women and 27.3 mm for men. The differences in measurements between genders were statistically significant. Of all glenoids, 46.3% of the glenoids were retroverted, whereas 53.7% of the glenoids were anteverted. The mean version for both genders was 0.77 degrees anteversion. The mean version was 1.16 degrees anteversion for women and 0.10 degrees anteversion for men. Of the 244 glenoids, 4 had bone defects. In our study, 39.8% of patients had mean maximum glenoid widths that were less than 25 mm, which is the smallest size available for most conventional glenoid baseplates. CONCLUSION: A significant portion of the Southern Chinese population has glenoid widths that are smaller than the smallest commercially available glenoid baseplates. Understanding the glenoid anatomy is crucial in the case of reverse shoulder arthroplasty, as it has significant implications in implant design, operative planning, and surgical outcomes.

Intra-operative femoral neck fracture during attempted dislocation of a reduced hemi-arthroplasty.

Fragility hip fractures are increasingly common and hemiarthroplasty is one of the standard treatments. Although a common surgery, it should be performed with great caution because of the poor premorbid and bone quality in this demographic. Intra-operative fractures can occur while attempting press fit of the femoral implant. However; vigilance often steps down once the implant is secured and the hip reduced. This case report reminds surgeons that a large amount of torque can be transmitted during intra-operative positioning, such as during an attempt of hip dislocation. This torque, in addition to the risk factor of osteoporotic bone, can result in iatrogenic fractures. Published literature regarding management of an intra-operative fracture while the prosthetic hip is still reduced is lacking. The authors propose that temporary prophylactic cerclage wiring is a prudent and safe procedure prior to hip dislocation.

Arthroscopy-assisted correction of hallux valgus deformity.

PURPOSE: Our purpose was to evaluate the clinical and radiologic results of arthroscopy-assisted hallux valgus deformity correction with percutaneous screw fixation. METHODS: Ninety-four feet underwent arthroscopy-assisted hallux valgus deformity correction. Patients in whom the 1,2-intermetatarsal angle could be reduced manually and who had no significant abnormality of the distal metatarsal articular angle were included, and an endoscopic distal soft tissue procedure was performed. Those patients with first tarsometatarsal hypermobility, in whom the 1,2-intermetatarsal angle cannot be reduced manually, or those who had a significantly abnormal distal metatarsal articular angle were excluded. Patients were assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) hallux-metatarsophalangeal-interphalangeal scale. The pre- and postoperative hallux valgus angle, intermetatarsal angle, distal metatarsal articular angle, and sesamoid position were measured. RESULTS: The mean score on the AOFAS scale was 93 +/- 8 out of 100 points. The hallux valgus angle improved from 33 degrees +/- 7 degrees (range, 20 degrees to 58 degrees ) to 14 degrees +/- 5 degrees (range, 4 degrees to 30 degrees ). The intermetatarsal angle improved from 14 degrees +/- 3 degrees (range, 10 degrees to 26 degrees ) to 9 degrees +/- 2 degrees (range, 5 degrees to 18 degrees ). Complications of hallux varus, skin impingement, screw breakage, and first metatarsophalangeal stiffness were experienced. Two patients with symptomatic recurrence had revision operation performed. CONCLUSIONS: Our study shows that arthroscopic correction of the hallux valgus deformity can achieve good clinical and radiologic results, provided that careful preoperative clinico-radiologic assessment is made to exclude patients contraindicated for the procedure. LEVEL OF EVIDENCE: Level IV, therapeutic case series.