Effects of posterior condylar osteophytes on gap balancing in computer-assisted total knee arthroplasty with posterior cruciate ligament sacrifice.

OBJECTIVE: Gap planning in navigated total knee arthroplasty (TKA) is a critical concern. Osteophytes are normally removed prior to gap planning, with the exception of posterior condylar osteophytes of the femur, which are removed after posterior condylar resection. This study investigated how posterior condylar osteophytes affect gap balancing during surgery. METHODS: This prospective study was conducted on 40 primary varus osteoarthritic knees with a posterior condylar osteophyte that underwent TKA navigation. For all knees, computed tomography (CT) was performed to evaluate osteophyte position. The extension gap and flexion gap were determined under navigation using a tension device with a distraction force of 44 lb. The extension gap and flexion gap were measured before and after osteophyte removal. RESULTS: This study revealed that the average osteophyte thickness after removal was 7.75 ± 5.34 mm. The average extension gap change was 0.64 ± 0.80 mm, and the average flexion gap change was 0.85 ± 1.12 mm. With respect to increases in the medial extension gap, lateral extension gap, medial flexion gap and lateral flexion gap, the average effects of posterior condylar osteophyte removal were 0.74 ± 0.81 mm, 0.53 ± 0.96 mm, 0.71 ± 0.97 mm and 1.00 ± 1.41 mm, respectively. Posterior condylar osteophyte thickness was also significantly associated with increases in the lateral extension gap (R2 = 0.107, p = 0.03), medial flexion gap (R2 = 0.101, p = 0.04) and lateral flexion gap (R2 = 0.107, p = 0.04). CONCLUSION: These results indicated that posterior condylar osteophytes of the femur affect gap balancing during TKA navigation.

Computer Navigation Helps Reduce the Incidence of Noise After Ceramic-on-Ceramic Total Hip Arthroplasty.

BACKGROUND: Noise after ceramic-on-ceramic (CoC) total hip arthroplasty (THA) is a well-recognized problem. Computer navigation has been shown to achieve desired implant orientation. Our aim was (1) to compare the incidence of noise between navigated and conventional CoC THAs and (2) to determine the factors associated with noise. METHODS: All patients undergoing CoC THA between March 2009 and August 2012 were considered for this study. Information regarding hip noise was obtained via telephone or postal interview. A comparable cohort of patients in navigated and conventional groups was used to evaluate the incidence of noise. RESULTS: A total of 375 CoC THAs using the same implant (202 navigated and 173 conventional) were evaluated. Patients <65 years of age had significantly greater incidence of noise (22.4% vs 6.1%; P < .001). To ensure similarity, a subgroup of cohort <65 years and a 32-mm head size was used to compare the incidence of noise between the navigated (68 THAs) and conventional (118 THAs) groups. Overall incidence of noise was significantly greater in the conventional group (28%) as compared with the navigated group (10%; P = .005). The relative risk of noise for the conventional vs the navigated group was 2.7 (P = .01), and for squeaking was 1.9 (P = .2). Squeaking THAs had significantly lower cup anteversion (13.4° ± 5.2°) as compared with the silent THAs (17.6° ± 6.9°; P = .01). CONCLUSION: Navigated CoC THAs were 2.7× less likely to have noise as compared with the conventional ones. Squeaking THAs had significantly lower cup anteversion as compared with the silent ones. Patients of age <65 years had significantly greater incidence of noise after CoC THA.

Lateral Release Can Increase Range of Flexion during Computer Assisted Total Knee Arthroplasty with Patellar Maltracking.

Objective: The patellar tracking is an important factor that affect range of motion after total knee arthroplasty (TKA). Intraoperative patellar maltracking during TKA can be improved by performing lateral release. We hypothesized that TKA with patellar maltracking after undergoing lateral release can increase intraoperative range of flexion. Material and Method: A prospective study was conducted on 110 knees that underwent computer assisted TKA. The patellar tracking was assessed with no thumb test technique. Fifty-two knees were classified into negative no thumb test group, and 58 knees were classified into positive no thumb test group. The positive no thumb test group further received lateral release with outside to inside technique. The range of flexion was recorded before and after final implantation in both groups, and recorded after lateral release in positive no thumb test group. Results: After final implantation, the negative no thumb test group had significant greater flexion angle than the positive no thumb test group (128.20° and 123.90°). The range of flexion after performing the lateral release in positive no thumb test group increased the flexion up to 127.60°. Thus, there was no significant difference from the negative no thumb test group (128.20°). After the lateral release was performed, the flexion angle had significantly increased by 3.70°. Conclusion: The results indicated that intraoperative lateral release in patellar maltracking can improve range of flexion in computer assisted TKA.

Clinical Outcomes of Interlaminar Percutaneous Endoscopic Uniportal Pars Decompression for Lumbar Spondylolysis.

BACKGROUND: To evaluate the clinical and radiological outcomes of a novel full endoscopic procedure performed via an interlaminar approach to decompress entrapped nerve roots in patients with lumbar spondylolysis. METHODS: Patients who underwent interlaminar percutaneous endoscopic pars decompression were included in this retrospective cohort study. Patients with back pain and dynamic lumbar instability were excluded from the study. Clinical parameters related to outcomes, including the Oswestry Disability Index (ODI) and visual analog scale (VAS) for leg pain, were assessed before and after surgery. The radiological outcomes, vertebral slippage percentage, and motion radiographs were evaluated preoperatively and postoperatively. RESULTS: Of the 11 patients included in the study, 5 had spondylolysis alone, 1 of whom had spondylolysis at L3-L4 and L4-L5, and 4 of whom had it at L5-S1; and 6 patients had spondylolysis in combination with spondylolisthesis, of whom 4 had involvement at L5-S1, 1 had involvement at L4-L5, and 1 had involvement at L3-L4. At a mean follow-up period of 22.64 months, 63.3% of patients achieved more than 50% improvement in ODI score and 90.91% of patients achieved more than 50% improvement in VAS score. Spondylolysis with vertebral slippage had inferior ODI improvement outcomes as compared with spondylolysis alone, but the VAS was not significantly different. No significant difference was observed on the slippage percentage observed between the pre- and postoperative periods. However, 1 patient experienced vertebral slippage after surgery, but fusion surgery was not required. CONCLUSIONS: Interlaminar percutaneous endoscopic pars decompression is a safe and successful treatment for patients with stable lumbar spondylolysis and nerve root compression. Even in situations in which vertebral slippage occurs, spinal fusion may not be the best option for all patients with lumbar spondylolysis. CLINICAL RELEVANCE: The interlaminar percutaneous endoscopic pars decompression is a safe and successful procedure for treatment of patients with stable lumbar spondylolysis and nerve root compression.

Comparison of clinical and radiographic outcomes between minimally invasive lateral approach and mini-midvastus approach in total knee arthroplasty.

OBJECTIVE: To compare clinical and radiographic outcome between minimally invasive lateral approach and mini-midvastus approach in total knee arthroplasty. MATERIAL AND METHOD: Patients with 28 knees were underwent total knee arthroplasty. They were divided into two groups. 14 knees were underwent total knee arthroplasty with lateral approach and the other 14 knees were operated with mini-midvastus approach. Clinical evaluation was done with visual analog scale from the second day to the fifth day after surgery. WOMAC score and range of motion was recorded at the third month. Including operative time and incision length was evaluated. Prosthetic component angles was measured with radiographic evaluation at the third month. RESULTS: The results revealed no significant difference between lateral approach and mini-midvastus approach in terms of visual analog scale, incision length, operative time, range of motion, WOMAC score and prosthetic alignment. CONCLUSION: Lateral approach in total knee arthroplasty had no difference clinical and radiographic outcomes compare with mini-midvastus approach.

Clinical Outcomes of Interlaminar Percutaneous Endoscopic Decompression for Degenerative Lumbar Spondylolisthesis with Spinal Stenosis.

The use of traditional open decompression alone in degenerative spondylolisthesis can lead to the development of postoperative spinal instability, whereas percutaneous endoscopic decompression can preserve the attachment of intervertebral muscles, facet joint capsules, and ligaments that stabilize the spine. The study's aim was to determine clinical as well as radiologic outcomes associated with interlaminar percutaneous endoscopic decompression in patients with stable degenerative spondylolisthesis. For this study, 28 patients with stable degenerative spondylolisthesis who underwent percutaneous endoscopic decompression were enrolled. The clinical outcomes in terms of the visual analogue scale (VAS) and Oswestry disability index (ODI) were evaluated. Radiologic outcomes were determined by measuring the ratio of disc height and the vertebral slippage percentage using lateral standing radiographs. The average follow-up period was 25.24 months. VAS and ODI were significantly improved at the final follow-up. In terms of ratio of disc height and vertebral slippage percentage found no significant difference between the preoperative and postoperative periods. One patient underwent further caudal epidural steroid injection. One patient underwent fusion because their radicular pain did not improve. Interlaminar percutaneous endoscopic decompression is an effective procedure with favorable outcomes in selected patients with stable degenerative spondylolisthesis.