Introduction: The long-term results of total hip replacement can be improved by accurate placement of the implants, leading to restoration of hip biomechanics and prevention impingement from of implant malposition. Pelvic obliquity from patient positioning during surgery prevents accurate intra-operative assessment of component placement. Computer navigation assisted total hip replacement can potentially eliminate these problems by providing feedback on prosthetic placement during surgery. The purpose of our study was to assess the accuracy of the component placement in computer navigation assisted THRs performed in our institution.

Methods: A total of 154 computer navigation assisted total hip arthroplasties performed between January 2004 and January 2005 were prospectively included in this study. Image free optical based navigation system (Navitrack™) was used. All procedures were performed by the senior author using MIS and open posterior approaches. Two independent observers performed analysis of the position of components and leg length discrepancy from standardized hip radiographs. Navigation values during surgery were compared with postoperative radiographic evaluation.

Results: The mean abduction and anteversion angles of acetabular component in postoperative radiographs were 41.4 ± 6.1 and 22.6 ± 3.8 degrees respectively, in comparison to the navigation values of 40.9 ± 4.0 and 22.9 ± 3.6 degrees respectively. The femoral neck offset and leg length discrepancy calculated from navigation were with in a mean of 1.5mm and 2.8mm, respectively. There was one complication consisting of a peri-prosthetic femoral fracture that was recognised during surgery and treated with revision of the femoral component to a long-stem prosthesis. There was no early post-operative dislocation or deep infection in this series.

Discussion: This study showed that computer navigation assisted THR provided predictable and reproducible results with accuracy in component placement and restorations of femoral neck offset and leg length.

Introduction: Technical and patient care improvements have occurred with the posterior mini-incision total hip replacement (THR). The hypothesis of this study was that these changes would provide better results for patients in the posterior mini incision surgery (MIS) THRs performed in our institution.

Methods: The clinical and radiographic results of 100 THRs performed with the posterior mini incision between January 2004 and October 2004 were compared with 100 mini incision THRs performed between December 2001 and September 2002. The second group was subjected to improved operative technique, the post-operative analgesia protocol, rehabilitation and patient advise. The acetabular cup abduction angle, anteversion angle, and stem varus/valgus alignment angle were measured in the post-operative radiographs in both groups. Pain score and Harris hip score were recorded at 6 weeks and 3 months. Statistical analysis was performed using Student 2-tailed t test, Chi-squared test and Wilcoxon-Mann-Whitney tests to compare the incision length, operative time, estimated blood loss, length of hospital stay, pain score and radiographic measurements between the two groups.

Results: The results showed that the component positions were not compromised in either group. There were statistical improvements in 2004 group with less estimated blood loss, decreased hospital stay, reduction of postoperative pain and opioid analgesic use and earlier muscle recovery. In 2004 group there were no complications of infection, dislocation, or sciatic palsy.

Discussion: The posterior mini-incision operation has shown improved results with experience and changes in technique and patient care treatment. We have continued our practice using this new technique.

Aims: We present a prospective study, with three-year follow-up, of the incidence, course and influence on surgical outcome of the abductor digiti minimi cord in Dupuytren’s contracture of the PIP joint of the little finger.

Methods: All patients presenting for surgery with primary Dupuytren’s contracture of the little finger over a six-month period were included in the study. Patterns of disease cords and joint involvement were noted. All fingers underwent fasciectomy of the central and pre-tendinous cords. If significant contracture remained the abductor cord was excised next, and the PIP joint itself released only if correction could still not be obtained. Contracture and range of movement of affected joints measured with goniometer pre-operatively, at each stage intra-operatively and at 3 months and 3 years post-op.

Results: The abductor cord was present in twleve of the nineteen fingers in the study, including all of those with ulnar-sided disease. The ulnar neurovascular bundle was found to be deep to the cord in nine fingers, encased by diseased tissue in two and displaced superficially in only one finger. Mean initial flexion deformity in these twelve fingers was 59, corrected to only 51 by resection of the central and pre-tendinous cords. Excision of the abductor cord further improved the contracture to 25 while PIP join release improved it to 6. Flexion deformity was 18 at three months and 21 at three years. For the seven fingers in which no abductor cord was found, mean initial flexion deformity was 42, improving to 24 following fasciectomy and 4 with joint release. It was 16 at three months and 18 at three years. No significant difference in outcome could be identified between the groups at three months or three years.

Conclusions: The abductor cord is present in roughly two-thirds of little fingers with contracture pf the PIP joint. The ulnar digital nerve usually lies deep to the abductor cord but in roughly one quarter of cases is either encased in or superficial to it. In affected fingers, resection of the cord accounts for more than half of the total correction obtained and three quarters of that obtained by fasciectomy. Presence of the ADM cord does not prejudice long-term outcome provided it is adequately resected.

Aims: We present a prospective study, with three-year follow-up, of the role and outcome of fasciectomy plus surgical release of structures of the PIP joint in Dupuy-tren’s contracture of the fifth ray. Methods: All patients presenting for surgery with primary Dupuytren’s contracture of the fifth ray over a six-month period were included in the study. All underwent fasciectomy followed sequentially by release of the abductor band, accessory collateral and checkrein ligaments as necessary. Deformity and range of motion in the PIPJ were measured by goniometer preoperatively, intra-operatively (post-fasciectomy and post-PIP release) and at three months and three years postoperatively. Results: Of the nineteen fingers in the study, eight (all mild deformity) achieved a full correction by fasciectomy alone. 78% correction remained at three months and 70% at three years. The remaining eleven fingers (initial mean deformity 70o flexion) obtained only a 38% correction by fasciectomy, increased to 90% with PIPJ release. Of this correction 64% was maintained at three months and 57% at three years. These figures include one recurrence of Dupuytren’s and are comparable with those of other techniques. Conclusion: We conclude that sequential PIPJ release is a useful technique for the correction of severe Dupuytren’s of the fifth ray involving that joint.

The aim of this study is to assess the accuracy of clinical examination of the knee compared to MRI and Arthroscopy in diagnosing significant internal derangement.

We performed a retrospective analysis on 245 patients who underwent an MRI of the knee over a two-year period. The MRI diagnoses were compared with both clinical and arthroscopic findings. There were 169 male and 76 female patients with an average age of 33 years. A history of significant trauma was seen in 98 (40%) patients. The commonest clinical diagnosis was isolated medial meniscal tear (25%). Anterior cruciate ligament (ACL) tear was diagnosed in 8% and lateral meniscal tear in 7% of cases. No definite clinical diagnosis could be reached in 32% of patients. MRI showed no significant abnormality in 103 (42%) patients. Medial meniscal tear was noted in 47 (19%), ACL tear in 20 (8%) and lateral meniscal tear in 10 (4%) of the MRI scans. 96 patients (39%) proceeded to arthroscopy after their MRI scans. The mean time from MRI scan to arthroscopy was 181 days. The MRI and arthroscopy findings were in complete agreement in 90 (94%) patients. Of the 6 patients whose MRI findings did not correlate with arthroscopy, 4 showed meniscal tears not seen at surgery and two diagnosed ACL ruptures subsequently shown to be normal at arthroscopy. Three of the 4 meniscal tears were of the inferior surface of the posterior horn of the medial meniscus and one of the inferior surface of the lateral meniscus. The films were reviewed independently by three experienced MR radiologists all of whom confidently diagnosed a tear in each case.

Clinical examination alone is not satisfactory in the diagnosis of knee injuries. MRI is a highly sensitive tool for diagnosis. Injuries that are commonly missed at arthroscopy can be diagnosed easily with MRI.