Results of Wagner SL revision stem with impaction bone grafting in revision total hip arthroplasty

Background:

As the number of total hip arthroplasties (THAs) performed increases, so do the number of required revisions. Impaction bone grafting with Wagner SL Revision stem is a good option for managing bone deficiencies arising from aseptic osteolysis. We studied the results of cementless diaphyseal fixation in femoral revision after total hip arthroplasty and whether there was spontaneous regeneration of bone stock in the proximal femur after the use of Wagner SL Revision stem (Zimmer, Warsaw, IN, USA) with impaction bone grafting.

Materials and Methods:

We performed 53 hip revisions using impaction bone grafting and Wagner SL Revision stems in 48 patients; (5 cases were bilateral) for variety of indications ranging from aseptic osteolysis to preiprosthetic fractures. The average age was 59 years (range 44-68 years). There were 42 male and 6 female patients. Four patients died after surgery for reasons unrelated to surgery. 44 patients were available for complete analysis.

Results:

The mean Harris Hip Score was 42 before surgery and improved to 86 by the final followup evaluation at a mean point of 5.5 years. Of the 44 patients, 87% (n=39) had excellent results and 10% (n=5) had good results. The stem survival rate was 98% (n=43).

Conclusion:

Short term results for revision THA with impaction bone grafting and Wagner SL revision stems are encouraging. However, it is necessary to obtain long term results through periodic followup evaluation, as rate of complications may increase in future.     

Pulmonary arterial diastolic pressure in acute myocardial infarction

Pulmonary arterial diastolic pressure has been shown to be a reliable estimate of left ventricular filling pressure. In 91 patients with acute myocardial infarction, the Swan-Ganz flow-directed catheter was used to measure pulmonary arterial diastolic pressure, which was correlated with clinical and radiographic estimates of left ventricular failure. The physical findings of a third sound gallop and rales were significantly correlated with the level of pulmonary arterial diastolic pressure. In the absence of either a third sound gallop or rales, the pulmonary arterial diastolic pressure was found to be increased in 47 percent of the patients. The presence of rales was a less sensitive determinant of left ventricular dysfunction than a third sound gallop alone or in association with rales. Radiographic findings of increasing pulmonary congestion were significantly correlated with the level of pulmonary arterial diastolic pressure. In the absence of radiographic pulmonary congestion, 24 percent of patients had abnormal pulmonary arterial diastolic pressure. We conclude that measurement of pulmonary arterial diastolic pressure increases the objectivity of the clinical evaluation in patients with acute myocardial infarction.     

The Hospital for the Ruptured and Crippled: William Bradley Coley, Third Surgeon-in-Chief 1925–1933

In January 1925, the Board of Managers of the New York Society for the Relief of the Ruptured and Crippled appointed William Bradley Coley, M.D., age 63, Surgeon-in-Chief of the Hospital for the Ruptured and Crippled (R & C) to succeed Virgil P. Gibney who submitted his resignation the month before. It would be the first time a general surgeon held that position at the oldest orthopedic hospital in the nation, now known as Hospital for Special Surgery (HSS). Coley had been on staff for 36 years and was world famous for introducing use of toxins to treat malignant tumors, particularly sarcomas. A graduate of Yale College and Harvard Medical College, Coley interned at New York Hospital and was appointed, soon after, to the staff of the New York Cancer Hospital (now Memorial Sloan Kettering Cancer Center) located at that time at 106th Street on the West Side of New York. With his mentor Dr. William Bull, Coley perfected the surgical treatment of hernias at R & C. He was instrumental in raising funds for his alma maters, Yale, Harvard and Memorial Hospital. His crusade in immunology as a method of treatment for malignant tumors later fell out of acceptance in the medical establishment. After his death in 1936, an attempt to revive interest in use of immunotherapy for inoperable malignancies was carried out by his daughter, Helen Coley Nauts, who pursued this objective until her death at age 93 in 2000. Coley's health deteriorated in his later years, and in 1933, he resigned as chief of Bone Tumors at Memorial Hospital and Surgeon-in-Chief at R & C, being succeeded at Ruptured and Crippled as Surgeon-in-Chief by Dr. Eugene H. Pool. William Bradley Coley died of intestinal infarction in 1936 and was buried in Sharon, Connecticut.     

Wagner Cone非骨水泥股骨柄联合转子下短缩截骨治疗成人Hartofilakidis Ⅲ型发育性髋关节发育不良

目的 探讨Wagner Cone非骨水泥股骨柄治疗成人Hartofilakidis Ⅲ型发育性髋关节发育不良（developmental dysplasia of the hip, DDH）的临床疗效。方法 回顾性分析2009年1月至2016年12月间在我院接受Wagner Cone非骨水泥股骨柄联合转子下短缩截骨全髋关节置换术（total hip arthroplasty, THA）的69例（81髋）成人高位DDH病人的临床资料。其中,女58例,男11例,平均年龄为35.4岁（16~65岁）,均为Hartofilakidis Ⅲ型DDH。临床主要症状为：患髋疼痛,不等长,跛行。双下肢长度平均差值为4.1 cm,平均脱位高度为5.8 cm。均采用股骨小转子下短缩截骨,臼杯均安装于真臼处,臼杯骨量覆盖80%以上。随访观察截骨处的愈合情况、患肢长度及并发症,采用髋关节Harris评分标准评定患肢功能。结果 平均随访4.5年（1.5~9.0年）。临床疼痛症状缓解,双下肢长度的平均差值降至1.1 cm。1例术中股神经不全损伤（术后4个月恢复）,截骨近端上移4例,截骨远端骨折1例,远端松动旋转移位2例,术后截骨端不愈合或延迟愈合5例,术后脱位2例,血栓2例,术后感染1例。病人髋关节功能较术前明显改善,Harris评分由术前的（30.4±4.3）分提高至（86.3±6.3）分,差异有统计学意义（t=5.836,P=0.031）。结论 对于Hartofilakidis Ⅲ型DDH病人,Wagner Cone非骨水泥股骨柄联合转子下短缩截骨治疗可有效平衡双下肢长度,缓解患髋疼痛,而且操作简单,并发症较少,可以获得满意的临床效果。     

Efficacy of Hyperbaric Oxygen Therapy in Diabetic Foot Ulcers Based on Wagner Classification

Diabetic foot ulcer is a common chronic complication of diabetes mellitus. In addition to conventional primary therapy, there are adjuvant therapy methods such as hyperbaric oxygen therapy for the healing of diabetic foot ulcer wounds. The present study aimed to determine the efficacy of hyperbaric oxygen therapy in diabetic foot ulcers based on Wagner classification. It was performed retrospectively from prospectively collected data. One hundred thirty patients with diabetic foot ulcers were assessed in 2 groups: 1 group received hyperbaric oxygen therapy; the other group did not. Patients were examined according to age, sex, ulcer grade based on Wagner classification; ulcer healing status; whether hyperbaric oxygen therapy was received; duration of diabetes in years; HbA1C, sedimentation, C-reactive protein levels; and presence of accompanying diseases, including peripheral arterial disease, chronic obstructive pulmonary disease, hypertension, chronic kidney disease, neuropathy, and retinopathy. The mean follow-up period was 19.5?±?4.45 months (range 12 to 28 months). Seventy-one (54.6%) patients received hyperbaric oxygen therapy, and 59 (45.4%) patients did not. All patients in Wagner grade 2 healed in both groups. In the group that received hyperbaric oxygen therapy for grade 3 and 4 patients, 35 (87.5%) and 11 (84.6%) healed, respectively. In total, 60 (84.5%) patients in the group that received hyperbaric oxygen therapy healed. The subgroup comparison conducted according to Wagner classification revealed no differences between the 2 groups of grades 2 and 5 patients. It also revealed that treatment had higher levels of efficacy in the healing of ulcers in grade 3 and 4 patients.     

Long-Term Survival and Reason for Revision of Wagner Resurfacing Hip Arthroplasty

The long-term survival of 270 Wagner resurfacing hip arthroplasties was determined. Two patients were lost to follow-up. Eleven hips remained unrevised at 15 to 22 years. Survival at 5, 10, and 16 years was 74%, 35%, and 17%, respectively. Survival in patients older than 55 years was better after 5 years than that for patients 55 years or younger (P = .0067). Femoral neck fracture occurred in 2% of the total cohort. Femoral component failure was an early and midterm complication. Acetabular component loosening was the most common reason for revision. The proportion of cases revised for acetabular component failure increased with time. These long-term data in this large series provide important historical results against which the relative benefits of contemporary designs may be evaluated.     

Purkinje cell activity during classical conditioning with different conditional stimuli explains central tenet of Rescorla–Wagner model

A central tenet of Rescorla and Wagner’s model of associative learning is that the reinforcement value of a paired trial diminishes as the associative strength between the presented stimuli increases. Despite its fundamental importance to behavioral sciences, the neural mechanisms underlying the model have not been fully explored. Here, we present findings that, taken together, can explain why a stronger association leads to a reduced reinforcement value, within the context of eyeblink conditioning. Specifically, we show that learned pause responses in Purkinje cells, which trigger adaptively timed conditioned eyeblinks, suppress the unconditional stimulus (US) signal in a graded manner. Furthermore, by examining how Purkinje cells respond to two distinct conditional stimuli and to a compound stimulus, we provide evidence that could potentially help explain the somewhat counterintuitive overexpectation phenomenon, which was derived from the Rescorla–Wagner model.The Rescorla–Wagner model of associative learning is arguably the most influential theory of associative learning in recent history. The model successfully predicted several behavioral phenomena (1). Moreover, in contrast to the Hebbian model, it is a prime example of an error correction process in which behavioral changes result from violation of expectations (2). A central tenet of the model is that the reinforcement value of a paired trial depends on the existing associative strength between the presented stimuli (3, 4). Neural mechanisms for several phenomena related to the Rescorla–Wagner model have already been proposed (5–16). In this paper, we present evidence from our eyeblink setup that builds on and advances prior thinking regarding the physiological basis of the Rescorla–Wagner model.In eyeblink conditioning, repeated presentations of a neutral conditional stimulus (CS), such as a tone or a light stimulus, followed by a blink-eliciting unconditional stimulus (US), such as an air puff to the cornea or electrical stimulation of the periorbital skin, results in the acquisition of a conditioned blink response (CR). Previous studies have shown that eyeblink conditioning depends on the cerebellum (17, 18) and that the cerebellar cortex plays a crucial role (19). Specifically, conditioned blink responses appear to be triggered by pause responses in GABAergic Purkinje cells (20). These pause responses, which are acquired gradually during conditioning (21), disinhibit cells in the cerebellar nuclei (22), thus allowing them to activate muscles controlling the eyelid (23, 24). Disinhibition of the cerebellar nuclei also activates GABAergic cells that project to the inferior olive (15). Because the US signal enters the cerebellum via the inferior olive (18), we hypothesized that the nucleo-olivary inhibition that arises during learning, suppresses the US signal and therefore reduces the reinforcement value of a paired trial, as postulated in the Rescorla–Wagner model.A surprising consequence of the model is that if a subject has learned to respond to two different CSs, the reinforcement value of a trial where both CSs and the US are presented will be negative and will cause extinction. This counterintuitive prediction has been confirmed in several learning paradigms including fear conditioning (25, 26), appetitive conditioning (27, 28), and eyeblink conditioning (10). The phenomenon is known as “overexpectation” because the subject may be said to “expect” a US that is more intense than the one it actually receives. We hypothesized that, within the context of eyeblink conditioning, overexpectation occurs because the compound CS results in stronger simple spike suppression in the Purkinje cells and, consequently, a stronger nucleo-olivary inhibition of the US signal, to the extent that the reinforcement value becomes negative.