This study aimed to explore whether intraoperative nerve monitoring can identify risk factors and reduce the incidence of nerve injury in patients with high-riding developmental dysplasia. We conducted a historical controlled study of patients with unilateral Crowe IV developmental dysplasia of the hip (DDH). Between October 2016 and October 2017, intraoperative nerve monitoring of the femoral and sciatic nerves was applied in total hip arthroplasty (THA). A neuromonitoring technician was employed to monitor nerve function and inform the surgeon of ongoing changes in a timely manner. Patients who did not have intraoperative nerve monitoring between September 2015 and October 2016 were selected as the control group. All the surgeries were performed by one surgeon. Demographics and clinical data were analyzed. A total of 35 patients in the monitoring group (ten male, 25 female; mean age 37.1 years (20 to 46)) and 56 patients in the control group (13 male, 43 female; mean age 37.9 years (23 to 52)) were enrolled. The mean follow-up of all patients was 13.1 months (10 to 15).Aims
Patients and Methods
The success rate of surgical debridement and prostheses retention for acute periprosthetic joint infection (PJI) is controversial. This study aims to report our experience in managing acute PJI following total knee arthroplasty (TKA) with surgical debridement and prostheses retention, and to identify the prognostic factors that may influence the surgical outcomes. A retrospective review from our prospective joint replacement register in Queen Mary Hospital, Hong Kong, of patients who were managed with surgical debridement and prosthesis retention for acute PJI after TKA between 1998 and 2013 was performed. The diagnosis of acute PJI was based on the 2011 Musculoskeletal Infection Society (MSIS) PJI diagnostic criteria. Both the early post-operative infections and the late haematogenous infections were included (Tsukayama type 2 and 3). Surgical outcomes were defined as successful if patients’ clinical symptoms had been relieved; inflammatory marker levels including C-Reactive Protein (CRP), Erythrocyte Sedimentation Rate (ESR) and White Blood Cell (WBC) count had returned to normal; X-rays showed no prosthetic loosening; and no lifelong antibiotic suppression was required. Outcomes were defined as failed if patients required any further surgeries (e.g., re-debridement, one or two-stage revision), or needed lifelong antibiotic suppression. All Patients’ perioperative data, i.e., age, primary diagnosis, pre-operative CRP, ESR, WBC, haemoglobin, albumin, glucose level, time lag from symptoms onset to debridement, synovial fluid total cell count and bacteriology were traced and recorded. SPSS 22.0 was used to calculate and compare the statistical differences between surgically successful group and failed group regarding the factors above.Purpose
Methods
OA knee with subchondral cyst formation presented differential microstructure and mechanical competence of trabecular bone. This finding sheds light on the pivot role of subchondral cyst in OA bone pathophysiology. Subchondral bone cyst (SBC) is a major radiological finding in knee osteoarthritis (OA), together with joint space narrowing, osteophyte and sclerotic bone formation. There is mounting evidence showing that SBC originates in the same region as bone marrow lesions (BMLs). The presence of subchondral bone cyst (SBCs), in conjunction with BMLs, was associated with the severity of pain, and was able to predict tibial cartilage lolume loss and risk of joint replacement surgery in knee OA patient. It is speculated that the presence of SBCs might increase intraosseous pressure of subchondral bone, and trigger active remodeling and high turnover of surrounding trabecular bone. Yet the exact effect of SBC on the structural and mechanical properties trabecular bone, which provides the support to overlying articular cartilage, remains to be elucidated. Therefore, this study aimed to investiate the microstructure and mechanical competence of trabecular bone of knee OA in presence or absence of SBC.Summary Statement
Introduction
Image-guided spine surgery requires registration between the patient anatomy and the preoperative computed tomography (CT) image. We have previously developed an accurate and robust registration technique for this application by using intraoperative ultrasound to acquire patient anatomy and then registering the ultrasound images to the CT images by aligning the posterior vertebral surfaces extracted from both modalities. In this study, we validate our registration technique across 18 vertebrae on three porcine cadavers. We applied the ultrasound-registration technique on the thoracic and lumbar vertebrae of the porcine cadavers using both single sweeps and double orthogonal sweeps. For each sweep pattern at each vertebra, we also randomly simulated 100 different initial misalignments and registered each misalignment. The resulting registration transformations are compared to gold standard registrations to assess the accuracy and the robustness of the technique. Orthogonal-sweep acquisition was found to be the sweep-pattern that performed the best and yielded a registration accuracy of 1.65 mm across all vertebrae on all porcine cadavers. It was found that the target registration errors (TRE) stay relatively constant with increasing initial misalignment and that the majority (82.7%) of the registrations resulted in TREs below the clinically recommended 2 mm threshold. In addition, it was found that the registration accuracy varies by the sweep pattern and the vertebral level, but neighbouring vertebrae tend to result in statistically similar accuracy. We found that our ultrasound-CT registration technique yields clinically acceptable accuracy and robustness on multiple vertebrae across multiple porcine cadavers.
