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Bone & Joint Open
Vol. 4, Issue 12 | Pages 932 - 941
6 Dec 2023
Oe K Iida H Otsuki Y Kobayashi F Sogawa S Nakamura T Saito T

Aims

Although there are various pelvic osteotomies for acetabular dysplasia of the hip, shelf operations offer effective and minimally invasive osteotomy. Our study aimed to assess outcomes following modified Spitzy shelf acetabuloplasty.

Methods

Between November 2000 and December 2016, we retrospectively evaluated 144 consecutive hip procedures in 122 patients a minimum of five years after undergoing modified Spitzy shelf acetabuloplasty for acetabular dysplasia including osteoarthritis (OA). Our follow-up rate was 92%. The mean age at time of surgery was 37 years (13 to 58), with a mean follow-up of 11 years (5 to 21). Advanced OA (Tönnis grade ≥ 2) was present preoperatively in 16 hips (11%). The preoperative lateral centre-edge angle ranged from -28° to 25°. Survival was determined by Kaplan-Meier analysis, using conversions to total hip arthroplasty as the endpoint. Risk factors for joint space narrowing less than 2 mm were analyzed using a Cox proportional hazards model.


Bone & Joint Open
Vol. 4, Issue 1 | Pages 19 - 26
13 Jan 2023
Nishida K Nasu Y Hashizume K Okita S Nakahara R Saito T Ozaki T Inoue H

Aims

There are concerns regarding complications and longevity of total elbow arthroplasty (TEA) in young patients, and the few previous publications are mainly limited to reports on linked elbow devices. We investigated the clinical outcome of unlinked TEA for patients aged less than 50 years with rheumatoid arthritis (RA).

Methods

We retrospectively reviewed the records of 26 elbows of 21 patients with RA who were aged less than 50 years who underwent primary TEA with an unlinked elbow prosthesis. The mean patient age was 46 years (35 to 49), and the mean follow-up period was 13.6 years (6 to 27). Outcome measures included pain, range of motion, Mayo Elbow Performance Score (MEPS), radiological evaluation for radiolucent line and loosening, complications, and revision surgery with or without implant removal.


The Bone & Joint Journal
Vol. 98-B, Issue 12 | Pages 1704 - 1710
1 Dec 2016
Nakamura N Inaba Y Aota Y Oba M Machida J N. Aida Kurosawa K Saito T

Aims

To determine the normal values and usefulness of the C1/4 space available for spinal cord (SAC) ratio and C1 inclination angle, which are new radiological parameters for assessing atlantoaxial instability in children with Down syndrome.

Patients and Methods

We recruited 272 children with Down syndrome (including 14 who underwent surgical treatment), and 141 children in the control group. All were aged between two and 11 years. The C1/4 SAC ratio, C1 inclination angle, atlas-dens interval (ADI), and SAC were measured in those with Down syndrome, and the C1/4 SAC ratio and C1 inclination angle were measured in the control group.


Bone & Joint Research
Vol. 5, Issue 9 | Pages 362 - 369
1 Sep 2016
Oba M Inaba Y Kobayashi N Ike H Tezuka T Saito T

Objectives

In total hip arthroplasty (THA), the cementless, tapered-wedge stem design contributes to achieving initial stability and providing optimal load transfer in the proximal femur. However, loading conditions on the femur following THA are also influenced by femoral structure. Therefore, we determined the effects of tapered-wedge stems on the load distribution of the femur using subject-specific finite element models of femurs with various canal shapes.

Patients and Methods

We studied 20 femurs, including seven champagne flute-type femurs, five stovepipe-type femurs, and eight intermediate-type femurs, in patients who had undergone cementless THA using the Accolade TMZF stem at our institution. Subject–specific finite element (FE) models of pre- and post-operative femurs with stems were constructed and used to perform FE analyses (FEAs) to simulate single-leg stance. FEA predictions were compared with changes in bone mineral density (BMD) measured for each patient during the first post-operative year.


The Bone & Joint Journal
Vol. 97-B, Issue 4 | Pages 492 - 497
1 Apr 2015
Ike H Inaba Y Kobayashi N Yukizawa Y Hirata Y Tomioka M Saito T

In this study we used subject-specific finite element analysis to investigate the mechanical effects of rotational acetabular osteotomy (RAO) on the hip joint and analysed the correlation between various radiological measurements and mechanical stress in the hip joint.

We evaluated 13 hips in 12 patients (two men and ten women, mean age at surgery 32.0 years; 19 to 46) with developmental dysplasia of the hip (DDH) who were treated by RAO.

Subject-specific finite element models were constructed from CT data. The centre–edge (CE) angle, acetabular head index (AHI), acetabular angle and acetabular roof angle (ARA) were measured on anteroposterior pelvic radiographs taken before and after RAO. The relationship between equivalent stress in the hip joint and radiological measurements was analysed.

The equivalent stress in the acetabulum decreased from 4.1 MPa (2.7 to 6.5) pre-operatively to 2.8 MPa (1.8 to 3.6) post-operatively (p < 0.01). There was a moderate correlation between equivalent stress in the acetabulum and the radiological measurements: CE angle (R = –0.645, p < 0.01); AHI (R = –0.603, p < 0.01); acetabular angle (R = 0.484, p = 0.02); and ARA (R = 0.572, p < 0.01).

The equivalent stress in the acetabulum of patients with DDH decreased after RAO. Correction of the CE angle, AHI and ARA was considered to be important in reducing the mechanical stress in the hip joint.

Cite this article: Bone Joint J 2015;97-B:492–7.


The Bone & Joint Journal
Vol. 96-B, Issue 3 | Pages 339 - 344
1 Mar 2014
Saito T Kumagai K Akamatsu Y Kobayashi H Kusayama Y

Between 2003 and 2007, 99 knees in 77 patients underwent opening wedge high tibial osteotomy. We evaluated the effect of initial stable fixation combined with an artificial bone substitute on the mid- to long-term outcome after medial opening-wedge high tibial osteotomy (HTO) for medial compartmental osteoarthritis or spontaneous osteonecrosis of the knee in 78 knees in 64 patients available for review at a minimum of five years (mean age 68 years; 49 to 82). The mean follow-up was 6.5 years (5 to 10). The mean Knee Society knee score and function score improved from 49.6 (sd 11.4, 26 to 72) and 56.6 (sd 15.6, 5 to 100) before surgery to 88.1 (sd 12.5, 14 to 100) and 89.4 (sd 15.6, 5 to 100) at final follow-up (p <  0.001) respectively. There were no significant differences between patients aged ≥ 70 and < 70 years. The mean standing femorotibial angle was corrected significantly from 181.7° (sd 2.7°, 175° to 185°) pre-operatively to 169.7° (sd 2.4°, 164° to 175°) at one year’s follow-up (p < 0.001) and 169.6° (sd 3.0°, 157° to 179°) at the final follow-up (p = 0.69 vs one year).

Opening-wedge HTO using a stable plate fixation system combined with a bone substitute is a reliable procedure that provides excellent results. Although this treatment might seem challenging for older patients, our results strongly suggest that the results are equally good.

Cite this article: Bone Joint J 2014;96-B:339–44.


The Journal of Bone & Joint Surgery British Volume
Vol. 90-B, Issue 10 | Pages 1392 - 1400
1 Oct 2008
Hayashi R Kondo E Tohyama H Saito T Yasuda K

We report the effects of local administration of osteogenic protein-1 on the biomechanical properties of the overstretched anterior cruciate ligament in an animal model. An injury in the anterior cruciate ligament was created in 45 rabbits. They were divided into three equal groups. In group 1, no treatment was applied, in group II, phosphate-buffered saline was applied around the injured ligament, and in group III, 12.5 μg of osteogenic protein-1 mixed with phosphate-buffered saline was applied around the injured ligament. A control group of 15 rabbits was assembled from randomly-selected injured knees from among the first three groups. Each rabbit was killed at 12 weeks.

The maximum load and stiffness of the anterior cruciate ligament was found to be significantly greater in group III than either group 1 (p = 0.002, p = 0.014) or group II (p = 0.032, p = 0.025). The tensile strength and the tangent modulus of fascicles from the ligament were also significantly greater in group III than either group I (p = 0.002, p = 0.0174) or II (p = 0.005, p = 0.022).

The application of osteogenic protein-1 enhanced the healing in the injured anterior cruciate ligament, but compared with the control group the treated ligament remained lengthened. The administration of osteogenic protein-1 may have a therapeutic role in treating the overstretched anterior cruciate ligament.


The Journal of Bone & Joint Surgery British Volume
Vol. 72-B, Issue 4 | Pages 597 - 600
1 Jul 1990
Santavirta S Konttinen Y Saito T Gronblad M Partio E Kemppinen P Rokkanen P

Cytological analysis of material aspirated from the effusion which occasionally develops around a polyglycolic acid (PGA) osteosynthesis implant showed a predominance of inflammatory monocytes and in particular lymphocytes. In order to discover whether PGA implants are immunologically inert, density gradient-isolated peripheral blood mononuclear cells were cultured in 0.2 ml of 10% delta FCS-RPMI 1640 culture medium supplemented with 10 mg PGA. Phytohaemagglutinin (PHA) lectin, a purified protein derivate of tuberculin (PPD) antigen and culture medium alone were used as positive and negative controls. We studied lymphocyte activation kinetics on days 0, 1, 3 and 5. Major histocompatibility complex locus II antigen (MHC locus II antigen) and interleukin-2 receptor (IL-2R) expression were analysed using the avidin-biotin-peroxidase complex (ABC) method and lymphocyte DNA synthesis by using 3H-thymidine incorporation and beta-scintillation counting. Especially on culture days 0 and 1, lymphocytes and monocytes were seen by light microscopy to be attached to PGA particles. However, our results show no PGA-induced lymphocyte DNA synthesis, but PGA-induced MHC locus II antigen and IL-2R activation marker expression was seen, greater than in negative controls, but less than that seen in PPD antigen driven lymphocyte response. This suggests that PGA is an immunologically inert implant material, but it does seem to induce inflammatory mononuclear cell migration and adhesion, leading to a slight non-specific lymphocyte activation. This activation is lower than that seen in mitogen and antigen-driven lymphocyte responses.