Two-incision total hip replacement: Intra-operative fluoroscopy versus imageless navigation for cup placement

A complete-pelvis segmentation framework for image-free total hip arthroplasty (THA): methodology and clinical study

BACKGROUND

Complete-pelvis segmentation in antero-posterior pelvic radiographs is required to create a patient-specific three-dimensional pelvis model for surgical planning and postoperative assessment in image-free navigation of total hip arthroplasty.

METHODS

A fast and robust framework for accurately segmenting the complete pelvis is presented, consisting of two consecutive modules. In the first module, a three-stage method was developed to delineate the left hemi-pelvis based on statistical appearance and shape models. To handle complex pelvic structures, anatomy-specific information processing techniques were employed. As the input to the second module, the delineated left hemi-pelvis was then reflected about an estimated symmetry line of the radiograph to initialize the right hemi-pelvis segmentation. The right hemi-pelvis was segmented by the same three-stage method,

RESULTS

Two experiments conducted on respectively 143 and 40 AP radiographs demonstrated a mean segmentation accuracy of 1.61±0.68 mm. A clinical study to investigate the postoperative assessment of acetabular cup orientations based on the proposed framework revealed an average accuracy of 1.2°±0.9° and 1.6°±1.4° for anteversion and inclination, respectively. Delineation of each radiograph costs less than one minute.

CONCLUSIONS

Despite further validation needed, the preliminary results implied the underlying clinical applicability of the proposed framework for image-free THA.

Enhanced recovery in total hip replacement: a clinical review

The outcome after total hip replacement has improved with the development of surgical techniques, better pain management and the introduction of enhanced recovery pathways. These pathways require a multidisciplinary team to manage pre-operative education, multimodal pain control and accelerated rehabilitation. The current economic climate and restricted budgets favour brief hospitalisation while minimising costs. This has put considerable pressure on hospitals to combine excellent results, early functional recovery and shorter admissions. In this review we present an evidence-based summary of some common interventions and methods, including pre-operative patient education, pre-emptive analgesia, local infiltration analgesia, pre-operative nutrition, the use of pulsed electromagnetic fields, peri-operative rehabilitation, wound dressings, different surgical techniques, minimally invasive surgery and fast-track joint replacement units.

Comparison of clinical outcome in primary total hip arthroplasty by conventional anterolateral transgluteal or 2-incision approach

Studies comparing the minimally invasive surgery with 2-incision technique (MIS-2) technique with the conventional transgluteal technique are lacking in the literatures. We compared the clinical outcomes in a series of 166 hips, including 83 MIS-2 total hip arthroplsty (THA) (group I) and another 83 matched-pair series (group II) using conventional transgluteal approach. Demographic data, hospital course, radiographic data, and functional outcome (Western Ontario and McMaster University Osteoarthritis Index and Harris hip score [HHS]) were investigated. The 2 groups significantly differed in 3 and 6-month HHS with a higher HHS in MIS-2 group. But the MIS-2 group had longer operation time, increased blood loss, and more complications. The current study indicates that the benefit of MIS-2 technique was only short-term with quicker functional recovery and shorter duration use of nonsteroid antiinflammatory drugs postoperatively.

Fluoroscopy cannot recognize intraoperative fracture in patients receiving 2-incision total hip arthroplasty

Intraoperative fluoroscopy is suggested as a standard procedure in 2-incision total hip arthroplasty. Between September 2003 and July 2004, 2-incision total hip arthroplasties were done in 18 hips with and another 18 hips without the use of fluoroscopy. In group 1, the anterior skin incision was initially limited to 5 cm. Fracture or instability was checked by fluoroscopy first and then the incision was enlarged to 8 cm for visualization. In group 2, incisions were made long enough to expose the surgical field. There were 2 femoral neck fractures in the fluoroscopy group. The fractures were linear in the anteromedial femoral neck and could not be detected by fluoroscopy. Such linear fractures if overlooked could result in serious complications such as fracture displacement or implant instability. Surgeons should not rely on intraoperative fluoroscopy to check implant stability, and visualization of the surgical field should not be compromised when doing minimally invasive approach for total hip arthroplasty.