Purpose: The objective of this study was to compare the results of a single mini-incision posterior approach with those of a standard posterior incision total hip arthroplasty.

Patients & methods: During the year 2005 52 patients were randomized to undergo total hip arthroplasty (THA) surgery through a short incision of 10 cm (or less) or a standard incision of 16 cm. 27 pts (20 females – 7 males) underwent THA through a posterior standard approach whereas 25 pts (19 females – 6 males) underwent THA through a posterior minimal invasive technique. Surgical indication was primary degenerative osteoarthritis in all patients. A single experienced surgeon performed all operations. In all patients the same cementless acetabulum and femoral component was used. The anaesthetic, analgesic, and postoperative physiotherapy protocols were standardized in both groups. The patients were compared with respect to the preoperative ASA score, incision length, hospital stay, intraoperative blood loss, postoperative blood transfusion, early mobilisation and satisfaction evaluated by the Harris Hip Score(HHS) and the visual analoque scale (VAS) for pain.

Results: The two groups were matched for age, grade according to the system of the American Society of Anesthesiologists and the preoperative Harris Hip Score. No significant difference was detected with respect to average surgical time, postoperative hematocrit, blood transfusion requirements, pain scores, or analgesic use. Additionally, we found no difference in early walking ability or length of hospital stay and no difference in component placement or functional outcome scores at the latest follow-up 6 – 12 months (mean 8 months) after surgery.

Conclusions: In arthroplasty the term ‘minimal invasive’ not only refers to the length of the skin incision but more so to its soft tissue protecting features and thereby to a better outcome. There was no evidence that the mini-incision technique resulted in less bleeding or less trauma to the soft tissues of the hip. Even more, it offers no significant benefit in the early postoperative or late period compared with a standard incision of 16 cm.

Background: Misplaced pedicle screws are associated with significant complications during posterior spinal instrumentation.

Purpose: The purpose of this study is to evaluate the efficacy of triggered electromyographic stimulation in predicting the appropriate placement of pedicle screws.

Study Design: Prospective clinical trial.

Patient Sample: Fifteen consecutive patients (3 males; 12 females).

Outcome Measures: Not applicable.

Materials and Methods: All patients underwent posterior thoracolumbar spine fusion. Surgery was performed for spondylolisthesis, spinal stenosis, degenerative scoliosis and fractures. All patients received continuous electromyographic monitoring during surgery. During insertion of pedicle screws the integrity of the medial pedicle cortex was tested by stimulating each screw head with a monopolar pedicle probe stimulator and recording the compound muscle action potentials. A threshold of 7 mA and below was considered indicative of pedicle breach. Intraoperative screw placement was verified with the use of image intensifier. Finally, all patients following surgery underwent plain radiographs and CT scan of the operated region to evaluate the position of the pedicle screws.

Results: One hundred and fourteen pedicle screws were inserted from T7 to S1 in all patients. There were no myogenic responses at the threshold tested. No screw had to be repositioned intraoperatively. There were no new neurologic deficits recorded following surgery. Review of the radiographs and CT scans obtained following surgery revealed no medial pedicle cortex breach. There were two screws that violated the lateral pedicle cortex, without any subsequent complications for the patients.

Conclusions: Our study suggests that the absence of myogenic responses following stimulation at a threshold of 7 mA and below during pedicle screw placement, is a strong indicator that no medial pedicle cortex breach has occurred.

Introduction: Minimally invasive augmentation techniques of vertebral bodies have been widely used in the treatment of painful osteoporotic vertebral compression fractures (VBCFs). Kyphoplasty seems to achieve pain relief and improvement in quality of life. However, the effect of kyphoplasty on the height and the kyphotic deformity of the vertebrae is now yet clear. The present study reports our experience in kyphoplasty procedures for osteoporotic VBCF’s.

Materials and Methods: A total of 105 VBCF (45 thoracic and 60 lumbar vertebrae) in 56 patients (16 male, 40 female; mean age: 69 years, range 32–87 years) were treated with kyphoplasty between 2002–2005. All patients were preoperatively evaluated with radiographs, MRI and bone scintigraphy, and postoperatively immediately following the procedure and 6 months later with radiographs. Eight patients were treated within a week from their injury (new fractures). All patients completed the Oswestry Disability Index Questionnaire pre- and immediately post-operatively and at 6 months. The height of the treated vertebrae and the kyphotic deformity were measured before, after the kyphoplasty and at 6 months. All procedures were performed under general anaesthesia and fluoroscopy guidance.

Results: 54 patients were included in the study; 2 patients expired from causes unrelated to the procedure. All patients experienced pain relief following the procedure and the average Oswestry Disability Index score decreased from 76% preoperatively to 12.4% postoperatively (P< 0.001) and to 18.5% (P< 0.001) at 6 months. The observed mean height restoration at 6 months was 3mm (range 0–15mm) (P=NS) and the kyphotic deformity correction was 3.70 (0–120) (P=NS). In the new fractures the height restoration was 7.1mm and the kyphotic correction 7.80 (P=0.01). There were no cases of pulmonary embolism nor were any significant cement leakages noted.

Conclusion: The treatment of painful osteoporotic VBCFs with kyphoplasty is safe and reduces pain and disability. However, it does not lead to restoration of the vertebral height nor to correction of the kyphotic deformity, except in new fractures.