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Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 8 - 8
1 Dec 2022
Okamoto T Glaris Z Goetz T
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Pathologies such as Scapho-Lunate Advanced Collapse (SLAC), Scaphoid Non-union Advanced Collapse (SNAC) and Kienbock's disease can lead to arthritis in the wrist. Depending on the articular surfaces that are involved, motion preserving surgical procedures can be performed. Proximal Row Carpectomy (PRC) and Four Corner Fusion (4CF) are tried and tested surgical options. However, prospective studies comparing the two methods looking at sufficient sample sizes are limited in the literature.

The purpose of this study was to prospectively compare the early results of PRC vs 4CF performed in a single centre.

Patients with wrist arthritis were prospectively enrolled (2015 to 2021) in a single centre in Vancouver, Canada. Thirty-six patients and a total of 39 wrists underwent either a PRC (n=18) or 4CF (n=21) according to pre-operative clinical, radiographical, and intra-operative assessment. Patient-Rated Wrist Evaluation (PRWE) scores were obtained preoperatively, as well as at six months and one year post operatively. Secondary outcomes were range of motion (ROM) of the wrist, grip strength, reoperation and complication rates. Statistical significance was set at p=0.05

Respectively for PRC and 4CF, the average PRWE scores at baseline were 61.64 (SD=19.62) and 63.67 (SD=20.85). There was significant improvement at the six-month mark to 38.81 (SD=22.95) (p=0.031) and 41.33 (SD=26.61) (p=0.007), then further improvement at the 12month mark to 33.11 (SD=23.42) (p=0.007) and 36.29 (SD=27.25) (p=0.002).

There was no statistical difference between the two groups at any time point.

Regarding ROM, statistical difference was seen in pronation for the PRC group at the 6month mark from an average of 72.18 deg to 61.56 deg and in flexion at the 12 month mark from 47.89 deg to 33.50 deg. All other parameters did not show statistically significant difference post operatively.

For ROM of the 4CF group, only flexion at the 12month mark showed statistically significant change from an average of 48.81 deg to 38.03 deg.

There was no statistical difference in pre-operative ROM between the two groups.

One patient in the 4CF group required a revision for delayed union, and three patients ended up with ulnar sided wrist pain.

Patients undergoing PRC and 4CF showed significant improvement in post operative PRWE scores, this reflects existing literature. For 4CF care must be taken to minimise ulnar sided wrist pain by relatively shortening the unar sided carpal column mass.

ROM analysis showed that patients lost some wrist flexion ROM post-operatively at the 12month mark with both PRC and 4CF. However, other ROM parameters were unchanged


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 9 - 9
1 Dec 2022
Glaris Z Okamoto T Goetz T
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SARS-CoV-2 emerged in Wuhan, China in December 2019 causing pneumonia and resulting in a pandemic, commonly known as COVID-19. This pandemic led to significant changes to our daily lives due to restrictions, such as social distancing, quarantining, stay at home orders and closure of restaurants and shops among other things. The psychological effects of this uncertainty as well as of these changes to our lives have been shown to be significant. This study is a prospective study investigating the mental effects of the pandemic on hand and wrist patients seen in our clinic during this pandemic.

A prospective database on wrist pain was used to identify patients seen in our hand clinic from January 1, 2018 to December 10, 2021. All participants had been diagnosed with either radial sided wrist pain or ulnar side wrist pain. The Center for Epidemiological Studies Depression (CES-D) Scale was used to assess the mental health of our participants before and during this pandemic. An independent samples t-test was used to compare the scores of the 2 groups.

A total of 437 CES-D questionnaires were collected during this period. 118 of them belonging to the pandemic group and 319 to the pre-pandemic group. A difference (p < 0 .05) in the CES-D score was observed between the pre-pandemic and during pandemic groups. The mean score for the pre-pandemic group was found to be 9.23 (8.94) and 12.81 (11.45) for the pandemic group. However, despite the increase in score, it didn't exceed the cut off score of 16 or greater used to assess depression.

Our results indicate that there was a slight increase in score for depression in hand and wrist patients, but not above the cut off level of 16 to be of a significant risk for depression. Other global studies have shown an increase in depression in the general public. Our mild results might be attributed to the fact that British Columbia did not implement severe restrictions compared to other countries or regions, i.e no stay at home orders. Additionally, our study population was skewed and included more middle age and older patients compared to younger ones and age might be a factor in keeping the score down.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XLIV | Pages 28 - 28
1 Oct 2012
Takemoto M Neo M Fujibayashi S Okamoto T Ota E Sakamoto T Nakamura T
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The accuracy of pedicle screw placement is essential for successful spinal reconstructive surgery. The authors of several previous studies have described the use of image-based navigational templates for pedicle screw placement. These are designed based on a pre-operative computed tomographic (CT) image that fits into a unique position on an individual's bone, and holes are carefully designed to guide the drill or the pedicle probe through a pre-planned trajectory. The current study was conducted to optimise navigational template design and establish its designing method for safe and accurate pedicle screw placement.

Thin-section CT scans were obtained from 10 spine surgery patients including 7 patients with adolescent idiopathic scoliosis (AIS) and three with thoracic ossification of the posterior longitudinal ligament (OPLL). The CT image data were transferred to the commercially available image-processing software and were used to reconstruct a three-dimensional (3D) model of the bony structures and plan pedicle screw placement. These data were transferred to the 3D-CAD software for the design of the template. Care was taken in designing the template so that the best intraoperative handling would be achieved by choosing several round contact surfaces on the visualised posterior vertebral bony structure, such as transverse process, spinous process and lamina. These contact surfaces and holes to guide the drill or the pedicle probe were then connected by a curved pipe. STL format files for the bony models with planned pedicle screw holes and individual templates were prepared for rapid prototype fabrication of the physical models. The bony models were made using gypsum-based 3D printer and individual templates were fabricated by a selective laser melting machine using commercially pure titanium powder. Pedicle screw trajectory of the bony model, adaptation and stability of the template on the bony model, and screw hole orientation of the template were evaluated using physical models. Custom-made titanium templates with adequate adaptation and stability in addition to proper orientation of the screw holes were sterilised by autoclave and evaluated during surgery.

During segmentation, reproducibility of transverse and spinous processes were inferior to the lamina and considered inadequate to select as contact surfaces. A template design with more bone contact area might enhance the stability of the template on the bone but it is susceptible to intervening soft tissue and geometric inaccuracy of the template. In the bony model evaluation, the stability and adaptation of the templates were sufficient with few small round contact surfaces on each lamina; thus, a large contact surface was not necessary. In clinical patients, proper fit for positioning the template was easily found manually during the operation and 141/142 screws were inserted accurately with 1 insignificant pedicle wall breach in AIS patient.

This study provides a useful design concept for the development and introduction of custom-fit navigational template for placing pedicle screws easily and safely.


The Journal of Bone & Joint Surgery British Volume
Vol. 81-B, Issue 1 | Pages 171 - 177
1 Jan 1999
Okamoto T Atsuta Y Shimazaki S

We studied the sensory afferent properties of normal, immobilised and inflamed rat knees by recording the activity of the medial articular nerve (MAN).

When the knee was inflamed by kaolin-carrageenan or immobilised for six weeks, MAN activity significantly increased during rest and continuous passive motion (CPM). The maximal discharge rate tended to increase depending on the angular velocity of the CPM. When the knees were then rested for one hour before again starting CPM, activity was further increased at the initial CPM cycle, the ‘post-rest effect’. Analysis of the conduction velocity showed that 94% and 66% of spike units on the recorded discharge of the immobilised and inflamed knees, respectively, belonged to fine nerve fibres.

Our findings show that the sensory receptors in the knee are sensitised in a similar manner by immobilisation and by inflammation, suggesting a relationship to pain. The post-rest effect may be related to a characteristic symptom of osteoarthritis called ‘starting pain’.


The Journal of Bone & Joint Surgery British Volume
Vol. 79-B, Issue 4 | Pages 609 - 615
1 Jul 1997
Gotoh E Inao S Okamoto T Ando M

We treated 31 consecutive patients of mean age 43 years (22 to 59) with severe osteoarthritis of the hip secondary to dysplasia by valgus-extension osteotomy. The clinical results were analysed for factors which may have affected the outcome. The procedure was carried out only on one side and was combined with a Chiari pelvic osteotomy in four patients. The angle of valgus was between 30 and 40° with 10 to 20° of extension. The mean follow-up was 15 years (12 to 18).

Clinical evaluation using Charnley’s modification of the system of Merle d’Aubigné and Postel showed that the mean score for pain had improved from 2.3 before operation to 4.2 at 15 years, and function from 2.3 to 4.2. Range of movement had decreased from 4.2 to 3.5. Fifteen patients (48.4%) had a pain score of 5 or 6 and were evaluated as satisfactory. Kaplan-Meier survivorship analysis showed a survival rate of 51% at 15 years after operation. Two preoperative factors had a significant positive correlation with the radiological results, namely the thickness of the capital drop osteophyte and the length of the roof osteophyte.

We suggest that this procedure is effective for advanced osteoarthritis in the dysplastic hip in young and active patients if these factors are satisfactory on the preoperative radiographs.


The Journal of Bone & Joint Surgery British Volume
Vol. 79-B, Issue 1 | Pages 83 - 86
1 Jan 1997
Okamoto T Inao S Gotoh E Ando M

We performed Charnley total hip arthroplasties on 64 patients (71 hips) between 1976 and 1984 for moderate congenital acetabular dysplasia in which a superolateral cement thickness of less than 20 mm was expected when the cup was placed in the true acetabulum at an angle of 45°. Of these, 59 hips were examined 10 to 17 years after operation; 37 (group A) had been operated on between 1976 and 1982 using Charnley’s original technique of cementing the acetabulum and 22 (group B) between 1983 and 1984 using more modern techniques.

In group A, aseptic loosening of the socket was observed in ten hips (27.0%) and the 17-year survival rate was 81.5%. In group B, loosening was noted in only one socket (4.5%) and the 13-year survival rate was 100%. The improved techniques produced significantly better long-term results in fixation of the cup in dysplastic hips without bone grafting.