"Single-use peripheral" vs "conventional" reaming in total hip arthroplasty: how to respect native centre of rotation and acetabular offset? A CT study.

PURPOSE: The respect of native hip offset represents a mainstay for satisfying results in total hip arthroplasty (THA). Historically, a great interest has been focused on restoration of femoral offset, while only in recent years, acetabular offset (AO) has been considered. The purpose of the current study was to compare the "single-use peripheral" reaming technique with the "conventional" one for the maintenance of the native COR of the hip and AO in patients undergoing to primary THA. METHODS: Eighty patients affected from primary hip osteoarthritis were prospectively enrolled in the study and were divided in two groups (Group A "single-use peripheral" and Group B "conventional" reaming technique). Pre- and post-operatively, AO, acetabular floor distance (AFd) and acetabular version (AV) were assessed through a CT scan. A comparison between groups for the radiological parameters, surgical time and complications was performed. RESULTS: The demographic data were similar in both groups. The complications rate and the AV did not differ statistically between groups. Group A presented a statistically significant shorter surgical time and lower variation between pre- and post-operative AO and AFd. Statistical significance was defined as p < 0.05. CONCLUSIONS: The "single-use peripheral" reaming technique demonstrated to be more reliable in reproducing the native COR and AO of patients undergoing to primary THA than the "conventional" one. The operative time was significantly reduced, and it may lead to a reduction in the infection risk even though it was not observed in the current study. Further research could be useful to validate such findings and to assess clinical impact and long-term survival of the implant.

First Metatarsal Bilateral Stress Fracture: A Case Report.

Introduction: Metatarsal stress fractures typically occur in the second and third metatarsus metaphysis, with only rare cases in the fourth and first. The main factors influencing its onset are repetitive stress from prolonged training, biomechanical factors and bone weakness. There is only a paucity of literature documenting first metatarsal stress fractures; the authors present a rare bilateral first metatarsal stress fracture. Case Report: A Caucasian 52-years-old amateur female runner with no other risk factors or medical condition was admitted in our institute with complaints of severe bilateral forefoot pain for 2 weeks arisen after a 20 km run of an amateur race. The patient presented bilateral hallux valgus (HVA) and advanced osteoarthritis of the first metatarsal-phalangeal joint, which is not usually considered a biomechanical risk factor for metatarsal stress fractures. Radiographs of both feet showed linear sclerosis, perpendicular to the diaphysis of the first metatarsal, approximatively in the half of the bone. Signs of osteoarthritis of the first metatarsal-phalangeal were also detected bilaterally.The patient was treated with rest, bilateral post-operative rocker sole shoes that she has worn for 6 weeks, cryotherapy, analgesics as needed and pulsed electromagnetic fields for 8 h per day for 40 days with a complete resolution of symptoms and the previous radiological findings. Conclusion: The authors believed that the bilateral HVA condition could be considered an indirect sign of overuse, and it may be investigated and eventually treated as a responsible for this pathologic condition.