Jeong Joon Yoo

Alumina-on-alumina total hip arthroplasty. A five-year minimum follow-up study.

BACKGROUND Ceramic-on-ceramic couplings are attractive alternative bearing surfaces that have been reported to eliminate or reduce problems related to polyethylene wear debris. Disappointing experiences with alumina ceramic bearings in the past have led to many improvements in the manufacture and design of ceramic implants. The purpose of the present study was to report the results of contemporary alumina-on-alumina total hip arthroplasties with regard to wear, osteolysis, and fracture of the ceramic after a minimum duration of follow-up of five years. METHODS We evaluated the results of a consecutive series of 100 primary alumina-on-alumina total hip arthroplasties that had been performed with use of a metal-backed socket and a cementless stem in eighty-four patients. All of the patients were sixty-five years of age or younger (mean age, forty-one years), and a single surgeon performed all of the procedures. After a minimum duration of follow-up of sixty months, one patient (one hip) had died and four patients (six hips) had been lost to follow-up, leaving a total of seventy-nine patients (ninety-three hips) available for study. All of these patients were evaluated clinically and radiographically with special attention to wear, periprosthetic osteolysis, and ceramic failure. RESULTS The mean Harris hip score was 97 points at the time of the latest follow-up evaluation. All prostheses demonstrated radiographic evidence of bone ingrowth. No implant was loose radiographically, and no implant was revised. Ceramic wear was not detectable in the thirty-seven hips in which the femoral head could be differentiated from the cup on radiographs. Periprosthetic osteolysis was not observed in any hip. A fracture of the alumina femoral head and a peripheral chip fracture of the alumina insert occurred in one hip following a motor-vehicle accident. CONCLUSIONS The results of contemporary alumina-on-alumina total hip arthroplasty with a metal-backed socket and a cementless stem were encouraging after a minimum duration of follow-up of five years. We believe that these improved alumina-on-alumina bearing implants offer a promising option for younger, active patients.

Ceramic liner fracture after cementless alumina-on-alumina total hip arthroplasty.

Advances in technology have reduced the risk of fracture of ceramic total hip arthroplasty implants, but concerns remain about fracture of both components. We retrospectively reviewed 133 patients (157 hips) who had cementless alumina-on-alumina total hip arthroplasties with a sandwich-type acetabular component. Six patients (seven hips) died and five patients (six hips) were interviewed by telephone (95% followup). The 122 patients (144 hips) examined had a minimum followup of 36 months (average, 45 months; range, 36-68 months). All acetabular cups and femoral stems were radiographically stable at the last followup. Five hips in five patients (3.5%) were revised because of ceramic liner fractures. Ceramic liner fractures occurred at a mean of 35 months (range, 24-48 months) postoperatively. Acetabular cups in the fracture group (n = 5) were more anteverted than those in the nonfracture group (n = 139). In three patients the fracture apparently occurred during squatting, resulting in hyperflexion and wide hip abduction. Early ceramic liner fracture was associated with impingement associated with excessive anteversion of the acetabular cup in Korean patients who habitually squat.Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Isolated fracture of the ceramic head after third-generation alumina-on-alumina total hip arthroplasty.

BACKGROUND While most reports of component fracture following alumina-on-alumina total hip arthroplasty have involved the acetabular liner, few have involved fracture of the alumina femoral head. In the present multicenter study, we investigated ceramic head fractures in a cohort of patients who underwent third-generation alumina-on-alumina total hip arthroplasty. METHODS We performed a retrospective study of 312 patients (367 hips) who underwent alumina-on-alumina total hip arthroplasty without cement at four participating centers with the use of a 28-mm BIOLOX forte femoral head and a BIOLOX forte liner from July 2001 to October 2003. Three hundred and five patients (359 hips) were evaluated at a mean of forty-five months postoperatively. Clinical follow-up with use of the Harris hip score and radiographic evaluation were performed at six weeks; at three, six, and twelve months; and every six months thereafter. Retrieved ceramic implants were examined by means of visual inspection. RESULTS Five hips (1.4%) in five patients were revised because of a ceramic head fracture during the follow-up period. The ceramic head fractures occurred during normal daily activities at a mean of 22.6 months postoperatively. A short neck had been used in all five hips in which a fracture occurred, compared with 121 (34.2%) of the 354 hips in which a fracture did not occur (p = 0.009). The fracture involved a circular crack along the circumference of the thinnest portion of the head component at the proximal edge of the bore. The fracture also involved multiple vertical cracks extending radially along the longitudinal axis from the circumference of the circular crack line to the lower edge of the head component. CONCLUSIONS In the present study, the rate of ceramic head fracture associated with one design of a short-neck modular alumina femoral head was 1.4% (five of 359). The extent to which these findings are generalizable to other designs that utilize this type of femoral head is unknown.

Alumina-on-alumina total hip arthroplasty: a concise follow-up, at a minimum of ten years, of a previous report.

We previously reported the five-to-six-year results of the use of third-generation alumina-on-alumina bearings in a consecutive series of 100 primary cementless total hip arthroplasties. This report presents the longer-term outcomes of these same bearings, at a minimum of ten years postoperatively. Eighty-six of eighty-eight hips available for the study retained the original bearings at the time of the latest follow-up. Thirteen hips were associated with noise, and six hips demonstrated fretting of the femoral neck on radiographs. Two hips required a change of the bearings because of a ceramic head fracture. The ten-year survival rate of the alumina-on-alumina total hip prostheses, with revision of any implant for any reason as the end point, was 99.0%. On the basis of those results, we concluded that the rate of survival of primary cementless total hip prostheses with third-generation alumina-on-alumina bearings is excellent at ten years. However, the risk of ceramic fracture, noise, and impingement between the metal neck and the ceramic liner should be a concern to surgeons, and patients should be informed of these risks before surgery.

Fate of Untreated Asymptomatic Osteonecrosis of the Femoral Head

BACKGROUND Magnetic resonance imaging has made it possible to detect asymptomatic lesions of osteonecrosis of the femoral head before abnormalities appear on plain radiographs. The extent of a necrotic lesion is known to be an important prognostic factor. In this study, we evaluated the fate of untreated asymptomatic osteonecrosis of the femoral head with an emphasis on the size of the lesion. We hypothesized that a lesion smaller than a certain size would not progress to symptomatic disease. METHODS One hundred and five initially asymptomatic hips of patients with bilateral nontraumatic osteonecrosis of the femoral head who had been followed without any treatment for at least five years or until pain developed were enrolled in this study. The extent of a lesion was estimated according to the area of the lesion based on a two-dimensional analysis on magnetic resonance images or on plain radiographs at the time of diagnosis. RESULTS Sixty-two hips became symptomatic, and forty-three hips remained asymptomatic for more than five years (average, eight years and seven months). Of the twenty-one hips with a small necrotic lesion (<30% of the area of the femoral head), one became painful; of the twenty-four hips with a medium-sized necrotic lesion (30% to 50% of the area of the femoral head), eleven became painful; and of the sixty hips with a large necrotic lesion (>50% of the area of the femoral head), fifty became painful. Forty-six of the sixty-two hips that became symptomatic required surgery. Pain developed within five years after the diagnosis in fifty-eight (94%) of the sixty-two symptomatic hips. CONCLUSIONS No treatment appears to be necessary for asymptomatic necrotic lesions with an area smaller than 30% of the femoral head, as the vast majority of these lesions will remain asymptomatic for more than five years.

Results of Multiple Drilling Compared with Those of Conventional Methods of Core Decompression

We performed multiple drilling as a femoral head-preserving procedure for osteonecrosis of the femoral head thinking the therapeutic effects of core decompression could be achieved by this simpler procedure than core decompression. We retrospectively reviewed 136 patients (163 hips) who had multiple drilling using 9/64-inch Steinmann pins for treatment of nontraumatic osteonecrosis of the femoral head. The mean followup for patients who did not require additional surgery (113 hips) was 87 months (range, 60-134 months). We defined failure as the need for additional surgery or a Harris hip score less than 75. After a minimum 5-year followup, 79% (31/39) of patients with Stage I disease and 77% (62/81) of patients with Stage II disease had no additional surgery. All (15/15) small lesions (<25% involvement) and 84% (37/44) of medium-sized lesions (25-50% involvement) were considered successful. Survival rates of patients with Ficat Stages I or II lesions were greater than survival rates for patients with Stage III lesions. Hips with a large necrotic area had poor results. We had one instance of subtrochanteric fracture through drill entry holes. Multiple drilling is straightforward with few complications and produces results comparable to results of other core decompression techniques.Level of Evidence: Level IV, therapeutic study (case series). See the Guidelines for Authors for a complete description of levels of evidence.

Subchondral fatigue fracture of the femoral head in military recruits.

BACKGROUND Subchondral stress fracture of the femoral head is a rare condition that usually occurs as an insufficiency fracture in people with poor bone quality. We evaluated the clinical characteristics of subchondral fatigue fractures of the femoral head that occurred in young, healthy military recruits. METHODS Between January 1998 and November 2001, seven subchondral fatigue fractures of the femoral head were treated in five patients. The characteristics of this condition were ascertained by assessing the clinical course as well as radiographs, bone scintigrams, and magnetic resonance images. RESULTS All patients were male military recruits in their early twenties in whom pain had developed within five months after recruitment. Definite abnormal findings were observed on the initial radiographs of four hips in three patients, and the femoral head was markedly collapsed in two of these four hips. Bone scintigrams were made of five hips in four patients, and all of them showed increased radionuclide uptake in the femoral head. In all affected hips, magnetic resonance images demonstrated a localized or diffuse bone-marrow-edema pattern in the femoral head and/or neck. A subchondral fracture line (a magnetic resonance crescent sign) was identified in all hips. In the patients who did not have collapse of the femoral head, the pain decreased gradually and disappeared completely within six months, with correspondingly improved findings on sequential magnetic resonance images. The patients with femoral head collapse were treated with total hip arthroplasty or an iliac bone strut graft. CONCLUSIONS When a military recruit or an athlete reports hip pain, a diagnosis of subchondral fatigue fracture of the femoral head should be considered.

Bisphosphonate use and increased incidence of subtrochanteric fracture in South Korea: results from the National Claim Registry

SummaryWe evaluated trends in the incidences of typical and atypical hip fracture in relation to bisphosphonate use in Korea from 2006 to 2010, using nationwide data obtained from the Health Insurance Review and Assessment Service (HIRA).IntroductionRecently, atypical hip fractures in the subtrochanteric region have been reported among patients on bisphosphonate. However, the association between atypical hip fracture and bisphosphonate is controversial. We evaluated trends in the incidences of typical and atypical hip fracture in relation to bisphosphonate use in Korea from 2006 to 2010, using nationwide data obtained from the HIRA.MethodsAll new visits or admissions to clinics or hospitals for a typical and atypical hip fractures were recorded nationwide by HIRA using the ICD-10 code classification. Typical and atypical hip fractures were defined as femoral neck/intertrochanteric and subtrochanteric fracture, respectively. Bisphosphonate prescription data were also abstracted from the HIRA database.ResultsThe absolute number of typical and atypical hip fracture increased during the study period. Although age-adjusted incidence rates of typical hip fractures were stable in men and women, those of atypical hip fractures increased in women. Nationally, the annual numbers of prescriptions of bisphosphonate also increased during the study period.ConclusionsThe results of this study suggest a possible causal relationship between bisphosphonate use and the increased incidence of atypical hip fracture in Korea.

Metal neck and liner impingement in ceramic bearing total hip arthroplasty

Although impingement between the neck of the metallic stem and the ceramic liner has been suspected to be the cause of ceramic liner failure in ceramic‐on‐ceramic total hip arthroplasty (THA), no report has directly demonstrated microscopic damage on ceramic liner. We performed 18 reoperations on 18 patients who had undergone third generation ceramic‐on‐ceramic THA. Considering impingement, 16 patients, who were reoperated more than 1 year after previous ceramic bearing THA, were evaluated. Retrieved alumina liners, showing evidence of impingement, were examined by means of visual inspection and scanning electron microscopy (SEM). Four of the 16 hips showed neck notching and black stained liners, evidence of metallic neck to ceramic impingement. Impinged alumina bearings had been implanted for an average of 62.5 months (range: 35–99 months) before reoperation. SEM of the black stained area demonstrated disruptive wear and loss of surface integrity. Furthermore, one liner had multiple microcracks, and its cross‐sectional SEM analysis revealed one microcrack propagating into the deep portion of the ceramic liner. Our observations suggest that metal neck‐to‐ceramic impingement in ceramic‐on‐ceramic THA can cause microcrack formation in ceramic liner.

Alumina-debris-induced osteolysis in contemporary alumina-on-alumina total hip arthroplasty. A case report

Aceramic-on-ceramic bearing coupling, because of its qualities of reduced friction and wear, is an attractive alternative bearing surface in total hip arthroplasty. The use of such bearing couplings is likely to reduce problems related to polyethylene wear debris1-6. Osteolysis has only rarely been reported in association with ceramic-on-ceramic bearing couplings, and reports are generally limited to cases involving early generation ceramic bearings or loosened prostheses7,8. Recently, several cases of osteolysis have been reported after total hip arthroplasty with use of a contemporary alumina bearing, but these reports only described the femoral scalloping seen on radiographs and did not present any histological evidence that ceramic particles were the causative factor9. We present the case of a patient who had formation of a large amount of osteolysis about both the acetabulum and the proximal part of the femur, induced by ceramic wear particles from a well-functioning contemporary alumina-on-alumina total hip prosthesis. The patient was informed that data concerning the case would be submitted for publication, and she consented. A sixty-three-year-old woman underwent bilateral total hip arthroplasty in June 1998 for the treatment of corticosteroid-induced osteonecrosis. The arthroplasties included the use of cementless implants (PLASMACUP SC-BiCONTACT; Aesculap, Tuttlingen, Germany) that incorporated 28-mm alumina femoral heads and alumina acetabular inserts (BIOLOX forte; CeramTec, Plochingen, Germany). The PLASMACUP had a roughened titanium plasma-sprayed exterior and a machined interior that accepted an alumina insert with a self-locking press-fit taper. The BiCONTACT stem was a tapered, rectangular, titanium-alloy implant, the proximal one-third of which was surface-treated with titanium plasma spray. The alumina head was secured to the stem by means of a tapered cone. After surgery, the patient did not present for regular follow-up visits and did not revisit our clinic until June 2006. At the time …