Similar radiological results with accelerometer-based navigation versus conventional technique in total knee arthroplasty.

BACKGROUND: The Zimmer iASSIST system is an accelerometer-based, portable navigation device for total knee arthroplasty (TKA) that does not require the use of a large console for alignment feedback as required in computer-assisted surgery. The purpose of this study was to determine the accuracy of the accelerometer-based system in component positioning and overall mechanical alignment. METHODS: Two groups of 30 patients each with primary osteoarthritis underwent TKA using either conventional method or Zimmer iASSIST navigation in 2013 was retrospectively studied. Patients were matched according to body mass index (BMI), gender and age. A senior arthroplasty surgeon performed all the operation using the same surgical approach. Perioperative and post-operative regimens were the same. All patients had standardized radiographs performed post-operatively to determine the lower limb mechanical alignment and component placement. RESULTS: There was no difference between the two groups for age, BMI, gender, side of operated knee and preoperative mechanical axis ( p > 0.05). There was no difference in the proportion of outliers for mechanical axis ( p = 0.38), coronal femoral angle ( p = 0.50), coronal tibia angle ( p = 0.11), sagittal femoral angle ( p = 0.28) and sagittal tibia angle ( p = 0.33). The duration of surgery, post-operative drop in haemoglobin level and transfusion incidence did not show statistically significant differences between the two groups ( p > 0.05). CONCLUSIONS: Our article showed that iASSIST was safe and remains a useful tool to restore mechanical axis. However, our data demonstrated no difference in lower limb alignment and component placement between the TKA that used accelerometer-based system and those that underwent conventional method.

Patients with knee osteoarthritis demonstrate improved gait pattern and reduced pain following a non-invasive biomechanical therapy: a prospective multi-centre study on Singaporean population.

BACKGROUND: Previous studies have shown the effect of a unique therapy with a non-invasive biomechanical foot-worn device (AposTherapy) on Caucasian western population suffering from knee osteoarthritis. The purpose of the current study was to evaluate the effect of this therapy on the level of symptoms and gait patterns in a multi-ethnic Singaporean population suffering from knee osteoarthritis. METHODS: Fifty-eight patients with bilateral medial compartment knee osteoarthritis participated in the study. All patients underwent a computerized gait test and completed two self-assessment questionnaires (WOMAC and SF-36). The biomechanical device was calibrated to each patient, and therapy commenced. Changes in gait patterns and self-assessment questionnaires were reassessed after 3 and 6 months of therapy. RESULTS: A significant improvement was seen in all of the gait parameters following 6 months of therapy. Specifically, gait velocity increased by 15.9%, step length increased by 10.3%, stance phase decreased by 5.9% and single limb support phase increased by 2.7%. In addition, pain, stiffness and functional limitation significantly decreased by 68.3%, 66.7% and 75.6%, respectively. SF-36 physical score and mental score also increased significantly following 6 months of therapy (46.1% and 22.4%, respectively) (P < 0.05 for all parameters). CONCLUSIONS: Singaporean population with medial compartment knee osteoarthritis demonstrated improved gait patterns, reported alleviation in symptoms and improved function and quality of life following 6 months of therapy with a unique biomechanical device. TRIAL REGISTRATION: Registration number NCT01562652.

The minimum 10-year results of a second-generation cementless acetabular shell with a polished inner surface.

The purpose of this prospective study was to evaluate the minimum 10-year outcomes and survivorship of the Reflection shell with a polished inner surface and an improved locking mechanism. Three hundred sixty-three total hip replacements with a mean follow-up of 11.6 years (range, 10.0-15.1) were evaluated. The mean Harris Hip and WOMAC scores at last follow-up were 87 and 77, respectively. Four cups were revised: 2 for infection and 2 for aseptic loosening. Thirteen cases underwent liner exchange for wear. Radiographic review of remaining cups identified 8.8% with identifiable peri-acetabular osteolysis and no cases of loosening. The overall 10- and 15-year Kaplan-Meier survivorship was 94% and 90% for the total hip arthroplasty system while the survivorship of the shell remained 99.4% at 15 years.

The relationship of the lateral cord of the brachial plexus to the coracoid process during arthroscopic coracoid surgery: a dynamic cadaveric study.

BACKGROUND: Arthroscopic coracoid decompression is performed for coracoid impingement and has also been advocated for arthroscopic repair of tears of the subscapularis tendon, placing the lateral cord or the musculocutaneous nerve at risk of injury. The dynamic relationship of the lateral cord to the coracoid while the upper limb is in abduction and traction in the shoulder arthroscopy position is not clear. PURPOSE: The purpose of this study was to evaluate the dynamic relationship of the lateral cord of the brachial plexus to the coracoid process during varying degrees of upper limb abduction in traction. STUDY DESIGN: Descriptive laboratory study. METHODS AND MATERIALS: The musculocutaneous nerves of 15 fresh-frozen cadaveric shoulders were carefully dissected and identified without mobilization of the nerve. The musculocutaneous nerve was then injected with radiopaque contrast mixed with methylene blue. The contrast would infiltrate retrogradely into the lateral cord, minimizing mobilization of the lateral cord. The specimens were mounted in the lateral decubitus position with 4.5 kg of traction to the forearm and anteroposterior radiographs were taken at 30 degrees and 60 degrees of abduction. The nearest distance of the lateral cord to the coracoid process was measured off the radiographs and the displacement with increase in shoulder abduction was determined. RESULTS: The mean nearest distance between the lateral cord and the coracoid tip at 30 degrees of shoulder abduction was 26.6 +/- 5.2 mm and it moved nearer at 60 degrees of abduction to 23.4 +/- 5.1 mm; the difference of 3.2 mm was statistically significant (P < .0005, 95% confidence interval, 2.5-3.9 mm). The shortest distance measured was 14.4 mm in 1 specimen at 60 degrees of abduction. CONCLUSION: The lateral cord moved closer to the coracoid process at 60 degrees than at 30 degrees of abduction under traction during simulated shoulder arthroscopy position using the lateral decubitus position. CLINICAL RELEVANCE: The margin of safety for lateral cord injury during arthroscopic surgery around the coracoid process is improved with lower abduction angles in the lateral decubitus position.

Vesico-hip fistula from bladder puncture with subsequent infected total hip arthroplasty.

The association of total hip arthroplasty and bladder injury has been well documented. Most cases of fistula formation between the bladder and the hip arthroplasty have occurred, either at the time of hip arthroplasty or subsequently. We report on this rare case where a bladder puncture resulted in infection of the arthroplasty. This occurred through an acetabular floor defect secondary to osteolysis and the subsequent fistula formation.

Laparoscopic nephrectomy: new standard of care?

OBJECTIVE: The pace of implementation of a laparoscopic nephrectomy programme is affected by factors including surgical expertise, case load, learning curves and outcome audits. We report our experience in introducing a laparoscopic nephrectomy programme over a 3-year period. METHODS: From January 2001 to December 2003, 187 nephrectomies were performed (105 by conventional surgery, 82 by laparoscopy). Hand-assisted laparoscopy was used predominantly. The indications for surgery, factors affecting the approach and outcome parameters were studied. A cost comparison was made between patients with similar-sized renal tumours undergoing laparoscopic versus open surgery. RESULTS: Most operations were performed for malignancy in both the open (70%) and laparoscopic (67%) surgery groups. The laparoscopic approach was most commonly used in upper tract transitional cell cancers (TCCs; 70% of 30 patients) and benign pathologies (49% of 35 patients), followed by radical nephrectomies (34% of 99 patients) and donor nephrectomies (44% of 23 patients). There was a rapid rise in laparoscopic surgeries, from 30% in 2001 to 58% in 2002. The median hospital stay was 5.8 days in the laparoscopic group and 8.1 days in the open surgery group. The procedure cost for laparoscopic surgery was 4,943 dollars compared with 4,479 dollars for open surgery. However, due to a shorter hospital stay, the total hospital cost was slightly lower in the laparoscopic group (7,500 dollars versus 7,907 dollars). CONCLUSION: The laparoscopic approach for various renal pathologies was quickly established with a rapid increase in the number of laparoscopic procedures.