Yasuhiro Saegusa

Reconstruction of the iliofemoral ligament with an artificial ligament for recurrent anterior dislocation of total hip arthroplasty

An 86-year-old woman underwent 4 revisions of hip arthroplasty and showed good position of both acetabular and femoral components. This was confirmed by roentgenographic measurements in the prone position. However, poor anterior acetabular covering after posterior inclination of the pelvis associated with lumbar kyphosis was observed in the standing position. Therefore, we reconstructed the iliofemoral ligament using a Leeds-Keio ligament to prevent anterior dislocation. At the 12-month follow-up evaluation, hip stability was confirmed, and the hip showed no further dislocation.

Does the location of the entry point affect the reduction of proximal humeral fractures? A cadaveric study

The selection of the correct entry point for stabilisation of long bone fractures and particularly of the humérus with intramedullary nailing is of paramount importance. The insertion of a nail from the correct entry point ensures anatomical alignment of the head and the shaft fragment. However, particularly for the humérus, the literature addressing this issue is obscure. Twenty cadaveric humeri without soft tissue attachment were studied. Two groups were studied: Group A (straight nail) and Group B (angled nail). A fracture of the surgical neck of the humérus was simulated. Then intramedullary nail was inserted through the correct entry hole. Displacement at the fracture site and force to reduce the displacement were measured. The average horizontal displacement was 2.5 ± 2.2 mm in Group A and 1.9 ± 1.1 mm in Group B. The humeral shaft tended to displace medially. The force required to reduce the produced displacement was usually less than 15 N. Anatomical reduction could not be obtained in 3/20 humeri even after applying a force of over 35 N. Our results of an average displacement of 2 mm following nail insertion, supports the significance of the entry point as a cause of loss of reduction at the fracture site post nail insertion. In most cases, anatomical reduction can be corrected with relative small forces, whereas in the rest the correction of the displacement is not feasible even with the application of substantial forces.

Cultured osteoblast synthesize nitric oxide in response to cytokines and lipopolysaccharide.

Nitric oxide (NO) is generated from L-arginine by NO synthase. NO has been reported to be produced by a variety of cell types such as vascular endothelial cells, macrophages, neutrophils and articular chondrocytes. A recent report demonstrated that NO inhibits osteoclast (OC) function and, in this way, is critically associated with bone metabolism. In the present study we have studied NO synthesis by osteoblasts (OBs). OB cell line, MC3T3-E1, was cultured with the various cytokines for 72 hrs. Nitrite, a stable endproduct of cell-generated NO, in the culture supernatant was then determined by using a spectrophotometric method based on Griess reaction. IL-1 alpha increased nitrite release in a dose-dependent fashion and a significant enhancement (p < 0.01) was attained at 10 U/ml. OBs released 14.2 nmol/4.0 x 10(4) cells of nitrite after 72 hrs stimulation by 100 U/ml IL-1 alpha. In contrast IL-1 beta, TNF-alpha and INF-gamma failed to affect NO synthesis by MC3T3-E1. The results suggest that OBs produce NO in response to IL-1 alpha and OB-induced NO may play a role in OB-OC interaction in the inflammatory process.

Inhibition of mitogen-induced response of human peripheral blood mononuclear cells by bucillamine, a new antirheumatic sulfhydryl drug.

SummaryThe mechanism of action of bucillamine, [N-(2-mercapto-2-methylpropionyl)-l-cysteine] (BC), a novel antirheumatic drug that is used in patients with rheumatoid arthritis (RA), was compared with that of d-penicillamine (DP). BC inhibited phytohemagglutinin (PHA)-induced DNA synthesis of peripheral blood mononuclear cells (PBMCs) in a dose-dependent manner, and this inhibition occurred both in the presence and absence of copper, whereas DP-induced inhibition required the presence of cupric ions. Significant inhibition of DNA synthesis was observed at a BC concentration of 10 μg/ml. The disulfide form of BC, but not DP disulfide, suppressed the proliferation of PBMCs. After preincubation of human peripheral blood T lymphocytes or Møs with BC or DP, these cells were combined and the overall PHA response was estimated. Inhibition of the PHA response was observed following pretreatment of either T lymphocytes or Møs with BC, whereas inhibition was attained only when T lymphocytes were pretreated with DP and copper. As sulfhydryl agents produce hydrogen peroxide in the presence of cupric ions, the effect of catalase on DP- and BC-induced inhibition of PBMC DNA synthesis was examined. Catalase partially reversed the BC-induced inhibition of DNA synthesis of PBMCs, and it restored the inhibition by DP and copper almost to the control level. These results suggest that BC suppresses the function of both T lymphocytes and Møs in the mitogen response of PBMCs, whereas the action of DP is targeted at T lymphocytes.

A new treatment for avulsion fracture of the calcaneus using an Ilizarov external fixator

INTRODUCTION In the treatment of avulsion fractures of the posterior calcaneal tuberosity, open reduction and internal fixation are prone to several complications. We describe a new treatment using an Ilizarov external fixator, which can minimise the complications and achieve sufficient stability of the displaced fragment. CASE PRESENTATION A 55-year-old woman sustained an avulsion fracture of the calcaneus. Examination revealed the development of bruising with extremely taut skin over the posterior prominence of the displaced bone. Radiographs demonstrated grossly proximal displacement of the tuberosity fragment. Surgery was exclusively percutaneous using an Ilizarov external fixator. The displaced fragment was adequately reduced and stabilised. Progressive weight bearing in the equinus position was initiated at the third week after surgery and the external fixator was removed at the seventh week. There was no skin necrosis or loss of reduction while the fixator was maintained. Postoperative follow-up for 2 years revealed full recovery. DISCUSSION Major postoperative complications after conventional open reduction and internal fixation include skin necrosis, skin irritation by metal implants and re-displacement of the reduced fragment. Our method of using an external fixator may decrease the incidence of these three complications. Skin incision and the risk of skin necrosis are inevitable during internal fixation. On the other hand, the use of an external fixator reduces or eliminates skin necrosis, as it is applied percutaneously for reduction and stabilisation of the fragment. External fixation is mostly recommended in cases of poor vascularity or bruising. In addition, skin irritation can be avoided upon removal of the external fixator. Re-displacement occurs occasionally as a serious complication in lag screw fixation, particularly in cases with poor purchase of the osteoporotic bone. Tension band wiring and application of an Ilizarov external fixator in avulsion fractures of the calcaneus can neutralise tension on the Achilles tendon during the healing process. Thus, both these methods are believed to provide sufficient mechanical stability to fix the fragment. CONCLUSION This new method, involving application of an Ilizarov external fixator, is recommended when the avulsion fragment is large enough to accommodate Ilizarov wires, especially in cases of circulatory problems or bruising.

Histologic analysis of allograft mixed with hydroxyapatite-tricalcium phosphate used in revision femoral impaction bone grafting.

Failed total hip arthroplasty (THA) often is accompanied by loss of bone stock. In cases in which revision THA becomes necessary, adequate stabilization of the implant can be difficult because of the bone loss. Bone can be reconstructed by using tightly packed morselized cancellous bone graft in combination with a cemented stem. However, worldwide availability of human bone is limited, and risks such as infection and antigenicity are associated with the use of allogeneic bone. These risks have led to the development of synthetic bone graft extenders. The objective of impaction bone grafting is to achieve stability of an implant and subsequently allow the restoration of living bone stock. To reduce the amount of allograft consumed, a mixture of morselized allograft and hydroxyapatite-tricalcium phosphate was used for impaction grafting in a series of 15 patients. In 2 patients who required re-revision arthroplasty, the areas of impacted graft were analyzed histologically. The results showed a complex mixture of residual hydroxyapatite-tricalcium phosphate, necrotic bone (graft), viable bone, and fibrous tissue. Although several pre-clinical studies have described the expansion of allograft with synthetic materials, this article represents the first description of histologic findings in human femoral impaction grafting with a combination of allograft and hydroxyapatite-tricalcium phosphate.

Total knee arthroplasty for rheumatoid knee with bilateral, severe flexion contracture: report of three cases

The treatment of patients with severe flexion contracture of the rheumatoid knee, deprived of ambulation for long periods of time, is challenging. Based on three cases, we indicate the potential risks of posterior dislocation of the knee after total knee arthroplasty. In this pathological condition, surgeons must carefully select the type of implant in order to avoid this serious complication. We also emphasize the importance of working on disuse muscle atrophy of trunk (back, abdominal) and lower limbs, both of which play an integral role in ambulation. The personality of each rheumatoid patient should be carefully considered when considering surgical and rehabilitation options.

Biomechanical Study Using the Finite Element Method of Internal Fixation in Pauwels Type III Vertical Femoral Neck Fractures

Background: Several factors are known to influence osseous union of femoral neck fractures. Numerous clinical studies have reported different results, hence with different recommendations regarding treatment of Pauwels III fractures: femoral neck fractures with a more vertically oriented fracture line. The current study aimed to analyze biomechanically whether this fracture poses a higher risk of nonunion. Objectives: To analyze the influence of one designated factor, authors believe that a computerized fracture model, using a finite element Finite Element Method (FEM), may be essential to negate the influence of other factors. The current study aimed to investigate a single factor, i.e. orientation of the fracture line toward a horizontal line, represented by Pauwels classification. It was hypothesized that a model with a vertically oriented fracture line maintaining parity of all other related factors has a higher stress at the fracture site, which would delay fracture healing. This result can be applicable to other types of pinning. Patients and Methods: The finite element models were constructed from computed tomography data of the femur. Three fracture models, treated with pinning, were constructed based on Pauwels classification: Type I, 30° between the fracture line and a horizontal line; Type II, 50°; and Type III, 70°. All other factors were matched between the models. The Von Mises stress and principal stress distribution were examined along with the fracture line in each model. Results: The peak Von Mises stresses at the medial femoral neck of the fracture site were 35, 50 and 130 MPa in Pauwels type I, II, and III fractures, respectively. Additionally, the peak Von Mises stresses along with the fracture site at the lateral femoral neck were 140, 16, and 8 MPa in Pauwels type I, II, and III fractures, respectively. The principal stress on the medial femoral neck in Pauwels type III fracture was identified as a traction stress, whereas the principal stress on the lateral femoral neck in Pauwels type I fracture was a compression stress. Conclusions: The most relevant finding was that hook pinning in Pauwels type III fracture may result in delayed union or nonunion due to significantly increased stress of a traction force at the fracture site that works to displace the fracture. However, in a Pauwels type I fracture, increased compression stress contributes to stabilize it. Surgeons are recommended not to treat Pauwels type III femoral neck fractures by pinning.

A case of the geniculate artery pseudoaneurysm after total knee arthroplasty: search for preventive measures by evaluation of arterial anatomy of cadaver knees

AbstractThis article presents an 80-year-old man with pseudoaneurysm of the inferolateral geniculate artery after total knee arthroplasty (TKA). The aim is to report this case and review possible preventive methods of pseudoaneurysm formation after TKA by investigating the relationship between knee arterial anatomy and the TKA procedure. Cadaveric evaluation demonstrates that the superomedial and inferomedial geniculate arteries are difficult to visualize. The anatomical position of the inferolateral artery makes it vulnerable to the surgical procedure during cutting of the tibia or while retracting soft tissue from the tibial edge, especially with minimal invasive surgery. In conclusion, careful subperiosteal release around the geniculate arteries is recommended. However, early recognition of pseudoaneurysm formation is even more essential than prevention. Level of evidence Therapeutic study, Level IV.

Surgical Treatment for Permanent Dislocation of the Patella in Adults

Permanent dislocation of the patella in adults is a rare condition that presents with complete irreducible lateral dislocation of the patella, combined with secondary changes, such as valgus deformity and leg-length discrepancy. Because these secondary changes cannot heal spontaneously after skeletal maturation if left untreated, the patients frequently possess pathology not limited to the knee joint and extending to the whole lower extremity, such as malalignment or leg-length discrepancy, that can develop into osteoarthritis of the knee. However, to our knowledge, few surgeons advocate the significance of correcting the malalignment in treating adult patients. We treated a 34-year-old woman with permanent dislocation of the patella in a 2-stage surgery, consisting of first-stage correction of valgus deformity and limb shortening using a Ilizarov external fixator and second-stage realignment of the dislocated patella over the trochlea. A follow-up examination conducted 3 years after the second operation revealed plantigrade gait with normal alignment of the lower extremity without limping and medial thrust. The patella was tracking centrally in the patellofemoral groove. Radiographs showed a neutral mechanical axis of the lower extremity, no evidence of patellar subluxation, and no deteriorating osteoarthritic changes at the tibiofemoral joint. This case highlights the importance of correcting secondary changes, such as valgus deformity and leg-length discrepancy, to reduce the risk of future osteoarthrosis and postoperative dislocation, especially when these deformities are substantial.