Katsuhiko Maezawa

Chronological changes of serum chromium levels after modern metal-on-metal total hip arthroplasty

We determined changes in serum chromium concentration every 6 months up to 3 years after implantation in 44 patients (mean age 63 (49–79) years, 35 women) who underwent modern metal-on-metal total hip arthroplasty (Metasul). The serum chromium levels increased between the first and second year after implantation (1 year: 1.05 (SD 0.76) µg/L, 2 years: 1.46 (SD 0.91) µg/L). A small increase was observed during the third year (1.61 (SD 1.31) µg/L). The clinical relevance of this finding is uncertain and should be determined in long-term studies on a large scale.

Seven Years of Chronological Changes of Serum Chromium Levels After Metasul Metal-On-Metal Total Hip Arthroplasty

Although many authors have reported the serum concentrations of metal ions in patients who had metal-on-metal coupling prostheses, most of the studies were not longitudinal, and the follow-up periods were short. We evaluated the longitudinal changes of serum chromium levels in 44 patients who had undergone unilateral metal-on-metal total hip arthroplasty for a minimum of 7 years postoperatively. Although there was a consistent increase in the mean serum chromium level until 3 years after implantation, there was little difference in the levels from years 3 to 7 postoperatively. Although the serum chromium concentration was low throughout postoperative follow-up for 7 years in about 25% of patients, the serum chromium level stayed high or showed gradual elevation in 16.3% of our patients.

Rotational acetabular osteotomy for severely dysplastic acetabulum.

Abstract The operative procedures chosen for arthrosis with severe acetabular dysplasia vary among orthopaedic surgeons. We operated on 250 hips using the rotational acetabular osteotomy (RAO) method of Ninomiya and Tagawa [8]. In this report, we describe the technique of RAO and the results of this procedure in patients with severely dysplastic hips. Among the 250 hips, there were 6 which were classified as Severin group V. In those hips, the CE angle was less than 0°, and the femoral head showed superolateral subluxation. After acetabular osteotomy with straight and curved osteotomes, smooth inferolateral rotation could be done in all cases. At the latest follow-up symptoms were improved remarkably, especially pain. Radiographically, adequate coverage of the femoral head was achieved and joint congruence improved in all 6 hips.

Reinfusion of unwashed salvaged blood after total knee arthroplasty in patients with rheumatoid arthritis

Autotransfusion with unwashed salvaged blood (USB) is effective for avoiding allogeneic blood transfusion (ABT) in patients undergoing total knee arthroplasty (TKA). We performed a retrospective study to determine the percentage of patients receiving ABT and the volume of postoperative blood drainage after introduction of autotransfusion with USB for patients with rheumatoid arthritis (RA) undergoing TKA. In 100 patients without autotransfusion (group 1) and 100 patients receiving autotransfusion of USB (group 2), we compared the number of patients who required ABT, as well as the postoperative drainage volume, ABT volume, and autotransfusion volume. In group 1, 83% of the patients received ABT, while only 47% received ABT in group 2, and there was a significant decrease (p < 0.001). However, the postoperative drainage volume was significantly increased in group 2 (p < 0.001).RésuméL’utilisation du sang récupéré en post-opératoire (USB) est une technique qui permet d’éviter la transfusion de sang autologue, chez les patients ayant bénéficié d’une prothèse totale du genou. Nous avons réalisé une étude rétrospective afin de déterminer le pourcentage de patients recevant le sang récupéré et le volume nécessaire. Nous avons réalisé cette étude pour déterminer le pourcentage de patients recevant une transfusion en rapportant ceci au volume de sang récupéré dans les drains après réalisation d’une auto-transfusion, ces patients étant porteurs d’une arthrite rhumatoïde. Chez 100 patients sans auto-transfusion (groupe 1) et 100 patients ayant bénéficié d’une auto-transfusion (groupe 2), nous avons comparé le nombre de patients ayant bénéficié d’une nouvelle transfusion ainsi que le volume du sang récupéré dans les redons, volume de sang réinjecté et l’importance de l’auto-transfusion. Dans le groupe 1, 83% des patients ont reçu une transfusion alors que seulement 47% en ont eu besoin dans le groupe 2. Il existe une différence significative entre ces deux groupes (p < 0.001). Cependant la perte sanguine dans les redons était significativement plus important dans le groupe 2 (p < 0.001).

Activation of fibrinolysis by reinfusion of unwashed salvaged blood after total knee arthroplasty

In 19 patients with RA and 20 with OA who underwent autotransfusion with unwashed salvaged blood (USB) after total knee arthroplasty, we performed serial measurement of D-dimer, FgDP, t-PA, and PIC in the plasma and salvaged blood. The PIC level at the completion of salvaged blood transfusion was closely correlated with the volume of USB reinfused in the RA group (p<0.001). The t-PA level of salvaged blood showed a significant positive correlation with the total volume of postoperative drainage in both the RA and OA groups (p<0.05). The increase of total postoperative drainage associated with reinfusion of USB is largely caused by an increase of t-PA in the salvaged blood.

Stress fractures of the femoral neck in child with open capital femoral epiphysis.

Stress fracture of the femoral neck has been considered a typical injury of two age groups: active youths and elderly people with osteoporosis. Its occurrence in children with an open capital femoral epiphysis is rare, and only 11 cases have been reported. Here we report two cases, in a 12-year-old boy and a 5-year-old girl (among the youngest patients on record). This fracture can be classified as a compression fracture or a tension fracture. Although tension fractures are not uncommon in military recruits and young athletes, all 13 cases (including our two cases) of femoral neck stress fracture associated with an open capital epiphysis were compression fractures that were treated conservatively.

Combined preoperative autologous blood donation and intra-operative cell salvage for hip surgery

Purpose. To review records of 161 consecutive hip surgery patients for whom preoperative autologous blood donation (PABD) was used in combination with intra-operative cell salvage (ICS). Methods. 114 women and 14 men aged 41 to 86 (mean, 64) years underwent 135 primary total hip arthroplasties (THAs), whereas 19 women and 7 men aged 16 to 52 (mean, 35) years underwent 26 rotational acetabular osteotomies (RAOs). Two or 3 weeks before the operation, patients deposited one unit (400 ml) of blood weekly, so long as their haemoglobin levels exceeded 110 g/1 (if they had osteoarthritis) or 100 g/1 (if they had rheumatoid arthritis). Patients were given oral ferrous sulphate, lactated Ringers solution, and recombinant human erythropoietin. 800 and 1200 ml of blood were deposited for patients undergoing THA and RAO, respectively. Intra-operatively, ICS was carried out using a continuous autotransfusion system. The blood from ICS was transfused first, and then the blood from PABD was transfused during the latter half of the operation. Results. By combining PABD and ICS, homologous blood transfusion was avoided in all patients, even in those with unexpected massive bleeding during surgery. In 3 patients, one unit of deposited autologous blood was discarded, because they showed no sign of anaemia. The mean total blood loss was almost 1.5 times higher in RAO than in THA patients (1095 vs 1550 ml). In the THA and RAO patients respectively, the mean amount of ICS was 181 and 210 ml, whereas the mean total blood transfusion volume was 975 and 1394 ml. No complications (including infection) related to autologous blood transfusion were observed during PABD, the surgery or the postoperative period. Conclusion. Homologous blood transfusion was avoided with the use of PABD and ICS. Preoperative donation of 800 and 1200 ml of blood (combined with ICS) seemed optimal, as only 3 units of blood were discarded.

Surgical Outcome for Hip Fractures in Patients with and without Parkinson's Disease:

Purpose. To compare surgical outcome of hip fractures (in terms of the ability to walk and complications) in patients with and without Parkinsons disease (PD). Methods. Records of 207 patients who underwent surgery for femoral neck fractures were reviewed. Of whom, 9 men and 26 women with PD aged 58 to 89 (mean, 76.8) years underwent hemiarthroplasty for subcapital fractures (n=22) or internal fixation for intertrochanteric fractures (n=13). The remaining 36 men and 136 women with no PD aged 61 to 96 (mean, 81.8) years underwent hemiarthroplasty (n=108) or internal fixation (n=64) for subcapital (n=120) or intertrochanteric (n=52) fractures. None of the patients had pathological fractures, and all had been ambulatory prior to the fracture. According to the Columbia classification system, severity of PD was grade II in 11, grade III in 11, and grade IV in 13 patients. Results. Respectively for the patients with and without PD at the one-year follow-up, 68.2% and 79.6% of those treated with hemiarthroplasty and 46.2% and 62.5% of those treated with internal fixation were able to walk with or without assistive devices. 81.8%, 63.6%, and 38.5% of the patients with grade-II, -III, and -IV PD, respectively, were able to walk at the one-year follow-up, compared to 73.3% of the patients without PD. Conclusion. Surgical treatment for hip fractures was appropriate for patients with grade-II or -III PD.

Serum Chromium Levels Before and After Revision Surgery for Loosened Metal-On-Metal Total Hip Arthroplasty

We investigated the changes of serum chromium levels before and after revision surgery in 10 patients (1 male and 9 females) who underwent exchange of a metal-on-metal articulation for a metal-on-polyethylene component because of aseptic loosening of a metal-on-metal total hip prosthesis. Of the 10 patients, 2 had bilateral metal-on-metal total hip arthroplasty. In the 8 patients who had no residual metal articulation, the mean serum chromium levels before and after revision surgery were 2.53 microg/L and 0.46 microg/L, respectively. In the 2 patients who still had a metal articulation on the contralateral side, the mean serum chromium levels before and after revision surgery were 2.85 microg/L and 1.90 microg/L, respectively. Moderate serum chromium levels in patients with metal-on-metal total hip arthroplasty show a decrease after removal of the metal-on-metal articulation.

Rotational acetabular osteotomy for acetabular dysplasia and osteoarthritis: a mean follow-up of 20 years

IntroductionRotational acetabular osteotomy (RAO), a joint-conserving surgery in which the femoral head coverage by autologous cartilage is improved to achieve joint stability, is one of the most common joint-conserving surgeries for acetabular dysplasia of the hip in adult patients. Favorable outcome of RAO for pre- and initial coxarthrosis has been reported with middle- to long-term observation; however, surgery should be selected for advanced coxarthrosis. The objective of this study was to investigate the long-term clinical outcomes and radiological arthritis changes in patients who were treated with RAO and could be followed for 15 years or longer, and to investigate the joint conservation rate by preoperative arthritis stage.Patients and methodsThe subjects were 156 patients (178 joints) treated with rotational acetabular osteotomy alone between January 1989 and June 2000. Of those, 106 patients (115 joints) were retrospectively investigated. The mean age at the time of surgery was 41.4 years (14–60 years), and the mean duration of follow-up was 20 years and 4 months (15–26 years and 7 months).ResultsThere were no significant differences in the Harris hip score among the three groups before surgery; however, the score was significantly lower in the advanced than pre/initial coxarthrosis cases at final follow-up. The joint conservation rate with the end point defined as time of total hip arthroplasty was 70.4% at 20 years after surgery. By stage, joint conservation rates were 88.9, 78.9, and 59.3% in pre-, initial, and advanced coxarthrosis cases, respectively, demonstrating a significantly lower rate in the advanced coxarthrosis cases (p = 0.034). The mean time to conversion was 23, 14.5, and 13.7 years in the pre-, initial, and advanced coxarthrosis cases, respectively.ConclusionThe outcome of rotational acetabular osteotomy in most hips with pre- or initial coxarthrosis was satisfactory. Rotational acetabular osteotomy is an effective surgery for treating symptomatic developmental dysplasia of the hip in selected patients.