Effect of the posterior sagging control device to the posterior tibial translation during posterior-stabilized total knee arthroplasty with modified gap technique.

PURPOSE: In modern total knee arthroplasty (TKA), flexion and extension gaps between the femur and tibia are equilibrated before implanting the final components. Uncontrolled intraoperative posterior tibial translation (PTT) could cause an artifactual widening of the flexion gap, which could lead surgeons to alter the femoral component size. We designed an intraoperative posterior sagging control device to prevent intraoperative PTT. In this study, we investigated whether the use of this device could prevent artifactual widening of the flexion gap. METHODS: Twenty-five patients, 21 women and four men, aged 74.2 years, were enrolled in this prospective study. All patients underwent postero-stabilized TKA using a navigation system. Intraoperative PTT, flexion and extension gaps with or without using the posterior sagging control device were measured with navigation system. These measurements were compared with or without the posterior sagging control device and after the final implantation also. RESULTS: There were significant differences between the measurements performed with or without the posterior sagging control device when compared to the post-implantation measurements. The use of the device reduced the number of patients with a >3 mm increase in flexion gap from 7 (28%) to 1 (4%). CONCLUSION: This study suggests that the posterior sagging control device prevents PTT and artificial flexion gap widening. This could prevent an unnecessary increase in component size.

Durable fixation with a modern fully hydroxylapatite-coated long stem in complex revision total hip arthroplasty.

We describe the use of a fully hydroxylapatite-coated long-stem femoral implant in a series of 40 complex revision total hip arthroplasties. All reconstructions involved severe bone loss or malalignment and were accomplished entirely without the use of augmentary bone graft. Outcomes were evaluated at 7 minimum years of follow-up (average, 10.2 years). Three stems were rerevised because of infection, trauma, and loosening with nonunion of a fracture. Bone ingrowth was radiographically evident by one postoperative year in all other cases. There were no cases of subsidence. Stress shielding with thigh pain was seen in one patient. The stem provided immediate stability and excellent long-term fixation in these reconstructions of severely diseased femurs.

Two-year experience using a limited-incision direct lateral approach in total hip arthroplasty.

We evaluated clinical, radiographic, and short-term recovery outcomes in an 18-month 1 surgeon series of 102 unilateral primary total hip arthroplasties performed by direct lateral approach through standard size (15-20 cm) and limited (<10 cm) incisions. Patients were blinded to incision type. Observed measures related to hematological status, transfusions, operative time, hospitalization time, narcotic use, rehabilitation, and discharge disposition did not appear to differ by incision type. Components were well placed in both groups. Intraoperative femoral fractures occurred in 2 limited-incision cases. At 2 years' minimum follow-up, we did not observe evidence that minimally invasive surgical technique provided clinically significant benefit to these patients.

Muscle strength improves after abductor-sparing periacetabular osteotomy.

UNLABELLED: We measured muscle strength after curved periacetabular osteotomy, one form of abductor-sparing periacetabular osteotomy, and then investigated the factors influencing postoperative muscle strength recovery. Curved periacetabular osteotomy was performed for acetabular dysplasia on 24 hips in 22 patients. All patients were females, with a mean age of 34.4 years. We based the severity of hip disease on the Tönnis classification. Isokinetic muscle strengths of the hips were measured preoperatively and 6 months and 12 months postoperatively. At 12 months postoperatively, the mean muscle strength (percentage difference to preoperative value) of the abductor was 42.2 Nm (129.6%), adductor 39.4 Nm (131.4%), flexor 48.4 Nm (121%), and extensor 45.8 Nm (130.5%), all of which exceeded the preoperative values. The 12-month postoperative muscle strength of patients with Grade 0 disease based on the Tönnis classification was greater in all directions than that of patients with Grades 1 and 2 disease. The preoperative stage was thought to be an essential factor in postoperative muscle strength recovery. LEVEL OF EVIDENCE: Prognostic study, Level II (lesser quality prospective study--eg, patients enrolled at different points in their disease or < 80% followup). See the Guidelines for Authors a complete description of levels of evidence.

Reconstructed hip joint position and abductor muscle strength after total hip arthroplasty.

We evaluated 60 limbs in 30 patients with unilateral primary total hip arthroplasty and nondiseased contralateral hip. The ratio of femoral offset (FO) to the body weight lever arm (FO ratio) and the ratio of the height of hip center (HC) to pelvic height (HC ratio) were calculated on radiographs. Isometric hip abductor strength was measured by dynamometer. The ratio of normalized strength of the reconstructed side to that of the nonoperated side was calculated (strength ratio). The FO ratio correlated positively to the strength ratio (r = 0.491; P = .0059), whereas the HC ratio correlated negatively (r = -0.568; P = .0011). Slight increase of FO ratio along with restoration of normal hip joint center erring on the side of slight inferomedial cup positioning appeared to optimize hip abductor function.

Pelvic motion during total hip arthroplasty with translateral and posterolateral approaches.

We devised a special instrument to assess intraoperative pelvic motion and used this device to measure intraoperative pelvic motion in three dimensions. A total of 100 total hip arthroplasties (THAs) were performed using this device. Two approaches were utilized: 52 THAs were performed with the posterolateral approach and the remaining 48 with the translateral approach. The average angle of pelvic tilt in the THAs with the translateral approach was less than that with the posterolateral approach. The average internal rotation angle was 1.75 degrees with the translateral approach and 14.25 degrees with the posterolateral approach. With the posterolateral approach, the internal rotation of the pelvis frequently occurred during retraction of the femur using a Hohmann's retractor placed at the anterior rim of the acetablum, with flexion and internal rotation of the affected hip.

Intraoperative pelvic motion in total hip arthroplasty.

In total hip arthroplasty (THA) in which the posterolateral approach is used, the pelvis can be easily inclined to roll both backward or forward on the operating table during the procedure. We prospectively studied 30 posterolateral-approach primary THA cases in which the surgeon used a specially devised goniometer that measured motions of the pelvis in the horizontal, frontal, and sagittal planes. We found that the pelvis primarily tilted forward during surgery, averaging 14.57 degrees of anterior tilt in the horizontal plane. The pelvic motion primarily occurred while the Hohman retractor was being applied to the femur to expose the acetabulum. Assessment of pelvic motion during surgery is an important component for successful positioning and placement of the acetabular cup with the posterolateral-approach THA.

A case of tuberculous granuloma at the supra-sternal notch that was difficult to differentiate from a thyroid tumor.

BACKGROUND: Despite a decline after World War II, the rate of tuberculosis remains higher in Japan than in other countries. We report a case of tuberculous granuloma at the supra-sternal notch that was difficult to differentiate from a thyroid tumor. CASE REPORT: The patient was a 75-year-old Japanese woman who was referred to our hospital for further investigations and treatment of an anterior neck tumor, that was diagnosed as a suspected of thyroid malignancy by another institute. The thyroid function and biological data were normal except for an elevated erythrocyte sedimentation rate. Imaging studies showed a mass at the supra-sternal notch, and the border between the tumor and the thyroid gland was indistinct. The tuberculosis bacillus group was identified by fine needle aspiration cytology. The patient was treated surgically for tuberculous granuloma, and histopathological findings revealed that the lymph node tuberuculosis had invaded the thyroid gland. We started anti-tuberculous therapy after the operation. The post-operative course was uneventful with good wound healing. CONCLUSIONS: When a markedly elevated erythrocyte sedimentation rate and c-reactive protein value are associated with an anterior neck mass, tuberculosis should be considered in the differential diagnosis of thyroid swelling. Fine needle aspiration cytology is a rapid, simple and effective diagnostic method for extra-pulmonary tuberculous lesions involving the neck. When there is abscess formation or features of compression, or if the mass cannot be differentiated from a thyroid tumor, combined therapy involving anti-tuberculous agents and surgery must be considered.

A quantitative anatomic characterization of the quadrilateral surface for periacetabular osteotomy.

The periacetabular osteotomy described by Ganz et al is used widely, and includes an outward osteotomy from the quadrilateral surface. Because intraarticular extension of the osteotomy can complicate the Ganz osteotomy, it is important to image the margin of the hip. To prevent this complication, and to do this procedure more safely, 32 hemipelves from cadavers were used in the current study. Some landmarks were selected that can be clarified on the quadrilateral surface during the periacetabular osteotomy. The acetabulum was hollowed out using an acetabular reamer of the same size as each femoral head, and the margin of the penetrated hole through the acetabulum was determined using these landmarks. The posterior margin of the hip is located approximately 2 cm anterior to the sciatic notch. The anatomic guidepoint for the osteotomy of the ischium averaged 14 mm inferior to the distal margin of the hip. By clarifying the margin of the hip presumed on the quadrilateral surface in this way, the periacetabular osteotomy can be done more safely, without causing complications such as intraarticular chisel penetration.

Effect of calf-thigh intermittent pneumatic compression device after total hip arthroplasty: comparative analysis with plantar compression on the effectiveness of reducing thrombogenesis and leg swelling.

The purpose of this study was to evaluate the efficacy of two intermittent pneumatic compression devices as prophylaxis against intravascular coagulation and leg swelling following total hip arthroplasty. We studied 121 patients by assessing thrombogenesis using the D-dimer level before and after total hip arthroplasty. In addition, the patients' postoperative swelling was evaluated by measuring the thigh and lower leg circumference. Altogether, 58 patients were assigned to the calf-thigh pneumatic compression group, and the other 63 were assigned to the plantar compression group; the two pneumatic compression devices were compared to evaluate which was more effective for reducing thrombogenesis. At 7 days postoperatively, the mean D-dimer levels of the calf-thigh compression group and the plantar compression group were 8.86 and 9.26 microg/ml, respectively. There was no significant difference ( P = 0.697) between the two groups. However, the increased ratio of the circumference of the thigh, which was compared after arthroplasty, averaged 1.22% in the calf-thigh compression group and 3.19% in the plantar compression group, which was significantly different ( P << 0.01). Calf-thigh pneumatic compression was found to be more effective than plantar compression for reducing thigh swelling during the early postoperative stage.

The effect of posterolateral reconstruction on range of motion and muscle strength in total hip arthroplasty.

Posterolateral reconstruction of the posterior capsule, piriformis tendon, and external rotators in total hip arthroplasty improves the stability of the hip joint. This study was performed to evaluate the effect of this reconstruction on range of motion (ROM) and circumferential muscle strength. We selected 58 limbs of 29 patients. Posterolateral reconstruction was performed in 13 patients (reconstruction group). Posterolateral reconstruction was not performed in 16 patients (nonreconstruction group). No significant differences were seen in preoperative and postoperative ROM between the 2 groups. The reconstruction group had significantly higher abduction muscle strength (P<.0001) and external rotation muscle strength (P<.01) than the nonreconstruction group. Posterolateral reconstruction may be effective in promoting the recovery of abduction and external rotator muscle strength, and it can improve joint stability without limiting ROM.

Vascular anatomy for rotational acetabular osteotomy: cadaveric study.

Rotational acetabular osteotomies are performed to correct dysplastic hips in young adults. However, there is a potential risk of intrapelvic vascular injury. To define the relation of these vascular structures to the bone around the acetabulum, we measured the distance and direction from the anteroinferior iliac spine to the external iliac artery and from the base of the superior pubic ramus to the obturator artery in 34 cadaveric hemipelves (17 male, 17 female; 19 left, 15 right). The distance to the external iliac artery was significantly shorter in females (average 31.7 mm) than in males (average 38.2 mm); and the distance to the intrapelvic entry portal of the obturator canal, through which the obturator artery passes, was significantly shorter in females (average 27.2 mm) than in males (average 33.4 mm). In addition, the external iliac artery was located significantly more ventral and closer to the anteroinferior iliac spine in right hemipelves than in left hemipelves. The intrapelvic entry portal of the obturator canal was located more caudodorsal to the base of the superior pubic ramus in females than in males. Care should thus be taken during surgery in light of our findings.

In vivo study of acute effects of hip and knee positions on blood flow in canine sciatic nerve.

We studied blood flow in the canine sciatic nerve using a laser Doppler flowmeter. Blood flow was measured in 20 hind limbs of ten adult dogs at varying angles of hip flexion, hip rotation and knee flexion. Blood flow decreased as flexion and internal rotation of the hip increased and also with only slight flexion of the knee. With 90 degrees knee flexion, the mean blood flow did not change significantly when the hip was internally rotated from 0 degrees to 30 degrees. When the knee was straight, the blood flow changed significantly during the same procedure. To prevent sciatic nerve palsy, attention should be paid to the positioning of the hip and knee during total hip arthroplasty.

Relationship between radiographic measurements of reconstructed hip joint position and the Trendelenburg sign.

We evaluated 60 limbs, including 34 primary total hip arthroplasties in 30 patients (mean age, 56 years) at a minimum of 2 years postoperatively. Femoral offset ratio (%FO) was calculated by dividing the femoral offset by the distance between the centers of the bilateral femoral heads on radiographs. The tilt angle of the pelvis by the Trendelenburg test was measured using the magnetic sensor system. In the limbs having a negative Trendelenburg sign after reconstruction, the %FO averaged 20.1% (range, 14.7% to 24.7%), and the tilt angle of the pelvis averaged +0.8 degrees (range, -1.0 degrees to +5.0 degrees ). The tilt angle of the pelvis correlated positively with %FO (P=.0160, r=0.407). The reconstructed hip joint position is crucial to improve hip abductor function.

Radioguided parathyroidectomy for reexploration of primary hyperparathyroidism-- a case report.

BACKGROUND: We report a case of radioguided parathyroidectomy using a hand-held gamma probe for the reexploration of primary hyperparathyroidism. CASE REPORT: The patient was a 66-year-old Japanese woman. She had previously undergone surgical exploration for primary hyperparathyroidism due to a left inferior parathyroid tumor detected by 99mTc-methoxyisobutylisonitrile (MIBI) scintigraphy. However, the pathological diagnosis of the resected tumor was adenomatous goiter. 99mTc-MIBI scintigraphy was performed again and revealed an abnormal uptake close to the right lower lobe of the thyroid. However, venous sampling for PTH measurements did not support this finding. Sestamibi was injected and the radioactivity was measured pre- and intraoperatively with a hand-held gamma probe. With the patient under general anesthesia, the tumor, which was adjacent to the right recurrent laryngeal nerve, was resected, but it contained only a low level of radioactivity ex vivo, indicating that it was not a parathyroid tumor. A hand-held gamma probe accurately located the radioactive parathyroid tumor in the right lower neck. The resected tumor measured 15 x 6 mm and weighed 331 mg. The pathological diagnosis was parathyroid adenoma. CONCLUSIONS: Radioguided parathyroidectomy is useful to localize parathyroid tumors not only in primary hyperparathyroidism at the initial neck exploration but also for reexploration.