Comparison of the extent to which total hip and total knee arthroplasty restore patient-reported physical function.

OBJECTIVE: To evaluate the extent to which elective total hip arthroplasty (THA) and total knee arthroplasty (TKA) for osteoarthritis (OA) restore normal patient-reported physical function in men and women. METHODS: Pain and physical function (WOMAC-PF) were prospectively measured pre- and post-operatively. The relationship between surgical procedure and achieving physical function equivalent to age and sex-matched adults with no hip or knee joint problems was modeled using sex-specific logistic regression. Percent change in function was also compared between groups using sex-specific generalized linear models adjusted for age, BMI, pain, comorbid conditions, time from surgery, and subsequent surgery. RESULTS: Individuals with pre- and post-operative WOMAC data were classified exclusively into either THA (287M:306F) or TKA (239M:424F) groups. The median follow-up was 476 (THA) and 474 (TKA) days for men, and 495 (THA) and 526 (TKA) days for women. MAIN OUTCOME: women with THA compared with TKA were more likely to achieve a normal level of postoperative PF while there were no significant differences between procedures in men. Additional analyses: we found slightly lower preoperative PF in THA compared with TKA. This difference resolved postoperatively in men, but women who underwent THA reported greater improvement and better PF than those who had TKA. CONCLUSION: In women, THA results in greater improvement in WOMAC-PF at approximately 1-year follow-up and better approximates physical function of community-dwelling older adults without OA than TKA does. In contrast, in men, a lack of between-group post-operative WOMAC-PF differences suggests that procedures result in a similar degree of improvement.

Trends and risk factors for prolonged opioid use after unicompartmental knee arthroplasty.

AIMS: The purpose of this study was to evaluate trends in opioid use after unicompartmental knee arthroplasty (UKA), to identify predictors of prolonged use and to compare the rates of opioid use after UKA, total knee arthroplasty (TKA) and total hip arthroplasty (THA). MATERIALS AND METHODS: We identified 4205 patients who had undergone UKA between 2007 and 2015 from the Humana Inc. administrative claims database. Post-operative opioid use for one year post-operatively was assessed using the rates of monthly repeat prescription. These were then compared between patients with and without a specific variable of interest and with those of patients who had undergone TKA and THA. RESULTS: A total of 4205 UKA patients were analysed. Of these, 1362 patients (32.4%) were users of opioids. Pre-operative opioid use was the strongest predictor of prolonged opioid use after UKA. Opioid users were 1.4 (81.6% versus 57.7%), 3.7 (49.5% versus 13.3%) and 5.5 (35.8% versus 6.5%) times more likely to be taking opioids at one, two and three months post-operatively, respectively (p < 0.05 for all). Younger age and specific comorbidities such as anxiety/depression, smoking, back pain and substance abuse were found to significantly increase the rate of repeat prescription for opioids after UKA. Overall, UKA patients required significantly less opioid prescriptions than patients who had undergone THA and TKA. CONCLUSION: One-third of patients who undergo UKA are given opioids in the three months pre-operatively. Pre-operative opioid use is the best predictor of increased repeat prescriptions after UKA. However, other intrinsic patient characteristics are also predictive. Cite this article: Bone Joint J 2018;100-B(1 Supple A):62-7.

Not all cementless femoral stems are created equal but the results may be comparable.

AIMS: The aim of this study was to compare the survivorship and radiographic outcomes at ten-year follow-up of three prospective consecutive series of patients each of which received a different design of cementless femoral components for total hip arthroplasty (THA). PATIENTS AND METHODS: In Cohort 1, 91 consecutive patients (100 hips) underwent THA with a cementless porous-coated anatomic femoral stem (PCA) between October 1983 and January 1986. In Cohort 2, 86 consecutive patients (100 hips) underwent THA with an extensively porous-coated cementless femoral stem (Prodigy) between June 1994 and October 1997. In Cohort 3, 88 consecutive patients (100 hips) underwent THA with a proximally porous-coated triple-tapered cementless stem (Summit) between April 2002 and October 2003. All three groups underwent prospective clinical and radiographic evaluation. RESULTS: Kaplan-Meier survivorship analysis of Cohort 1 was 91% (95% confidence interval (CI) 88 to 94) with an endpoint of revision for any reason and 97% (95% CI 95 to 99) with aseptic loosening as the endpoint. Survivorship of Cohort 2 was 88% (95% CI 79 to 97) for revision for any reason and 100% for aseptic loosening. Survivorship of Cohort 3 was 95% (95% CI 91 to 99) for revision for any reason and 100% with aseptic loosening as the endpoint. CONCLUSION: With revision for aseptic loosening of the femoral component as the endpoint, the three femoral components with different design philosophies demonstrated excellent survivorship, ranging from 97% to 100% at ten years. Cite this article: Bone Joint J 2017;99-B(1 Supple A):14-17.

Dislocation of a primary total hip arthroplasty is more common in patients with a lumbar spinal fusion.

AIMS: Lumbar fusion is known to reduce the variation in pelvic tilt between standing and sitting. A flexible lumbo-pelvic unit increases the stability of total hip arthroplasty (THA) when seated by increasing anterior clearance and acetabular anteversion, thereby preventing impingement of the prosthesis. Lumbar fusion may eliminate this protective pelvic movement. The effect of lumbar fusion on the stability of total hip arthroplasty has not previously been investigated. PATIENTS AND METHODS: The Medicare database was searched for patients who had undergone THA and spinal fusion between 2005 and 2012. PearlDiver software was used to query the database by the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) procedural code for primary THA and lumbar spinal fusion. Patients who had undergone both lumbar fusion and THA were then divided into three groups: 1 to 2 levels, 3 to 7 levels and 8+ levels of fusion. The rate of dislocation in each group was established using ICD-9-CM codes. Patients who underwent THA without spinal fusion were used as a control group. Statistical significant difference between groups was tested using the chi-squared test, and significance set at p < 0.05. RESULTS: At one-year follow-up, 14 747 patients were found to have had a THA after lumbar spinal fusion (12 079 1 to 2 levels, 2594 3 to 7 levels, 74 8+ levels). The control group consisted of 839 004 patients. The dislocation rate in the control group was 1.55%. A higher rate of dislocation was found in patients with a spinal fusion of 1 to 2 levels (2.96%, p < 0.0001) and 3 to 7 levels (4.12%, p < 0.0001). Patients with 3 to 7 levels of fusion had a higher rate of dislocation than patients with 1 to 2 levels of fusion (odds ratio (OR) = 1.60, p < 0.0001). When groups were matched for age and gender to the unfused cohort, patients with 1 to 2 levels of fusion had an OR of 1.93 (95% confidence interval (CI) 1.42 to 2.32, p < 0.001), and those with 3 to 7 levels of fusion an OR of 2.77 (CI 2.04 to 4.80, p < 0.001) for dislocation. CONCLUSION: Patients with a previous history of lumbar spinal fusion have a significantly higher rate of dislocation of their THA than age- and gender-matched patients without a lumbar spinal fusion. Cite this article: Bone Joint J 2017;99-B:585-91.

Total hip arthroplasty with cement and without acetabular bone graft for severe hip dysplasia. A concise follow-up, at a minimum of twenty years, of a previous report.

We previously evaluated a cohort of fifty-three patients with severe hip dysplasia (Crowe Type-II, III, or IV subluxation) who underwent a total of sixty-six Charnley total hip arthroplasties. The acetabular component was placed at the anatomic hip center, the superolateral defect was filled with cement, and no bone-grafting was used to supplement the acetabular wall. All but one patient, who was lost to follow-up, were followed until death or for a minimum of twenty years. Radiographic and functional follow-up data were collected prospectively. This retrospective review included twenty-four patients (thirty-four hips) who were alive at a minimum of twenty years following the surgery. Fourteen (22%) of the sixty-five hips underwent revision of a component, with eleven of the revisions performed because of aseptic loosening. Eight of those eleven hips underwent revision because of acetabular loosening alone; two, because of femoral loosening alone; and one, because of loosening of both components. The combined prevalence of revision because of aseptic loosening of the acetabular component and radiographic evidence of failure of the acetabular component was 28% (eighteen hips). With the numbers available, the need for acetabular revision was not associated with the percentage of cement coverage (p = 0.362) or the Crowe classification (p = 0.159). At a minimum of twenty years postoperatively, the survivorship of the acetabular component was 86% +/- 8% with revision because of aseptic loosening as the end point and 82% +/- 10% with revision because of aseptic loosening or radiographic evidence of loosening as the end point. The results that we evaluated at a minimum of twenty years after use of this technique can be compared with the results of other techniques in studies with similar long-term follow-up periods.

Activity-dependence of the "safe zone" for impingement versus dislocation avoidance.

Presently, the basis for optimal cup positioning to minimize the likelihood of dislocation rests upon subjective clinical impressions. To help elucidate optimal cup positioning more objectively, and to clarify the distinction between impingement avoidance and dislocation avoidance, kinematic and kinetic inputs for seven dislocation-prone activities were applied to finite element models of a contemporary 22-mm modular total hip reconstruction. Twenty-five cup placement positions (combinations of 30, 40, 50, 60, and 70 degrees of abduction with 0, 10, 20, 30, and 40 degrees of anteversion) were chosen to include the conventional 'safe zone' of 30-50 degrees of tilt and 5-25 degrees of anteversion. Activities studied were: rising from a low seat (toilet) and from a normal height chair, leg-crossing while seated, tying a shoe from a seated position, bending at the hip from an erect stance to retrieve an object on the floor (stooping), a standing pivot maneuver, and rolling over in bed. Neck-on-cup impingement occurred during one or more of the dislocation-prone activities at all 25 cup positions. Of the 175 combinations of cup position and kinetic challenge, dislocation and impingement events both occurred for 51 situations, while impingement occurred in 45 instances without dislocation, and dislocation occurred in 10 instances without impingement. Neither dislocation nor impingement was observed in the 69 other combinations of cup position and loading challenge. Kappa statistics showed dislocation and impingement, as outcome measures of activity-dependent challenges, exhibit little more than chance agreement. Therefore, the use of impingement range of motion (ROM) as a predictor of a given cup position's vulnerability to dislocation should be viewed cautiously.

Three-phase bone scan and indium white blood cell scintigraphy following porous coated hip arthroplasty: a prospective study of the prosthetic tip.

Although few reports address the use of three-phase bone scanning (TPBS) and 111In-labeled white blood cell (In-WBC) scintigraphy in hip arthroplasty utilizing a porous coated prosthesis, the literature suggests that scintigraphic patterns in the uncomplicated patient may differ from that seen in the cemented prosthesis. In an attempt to determine the scintigraphic natural history, 25 uncomplicated porous coated hip arthroplasties in 21 patients were prospectively studied with serial TPBS and In-WBC at approximately 7 days, and at 3, 6, 12, 18, and 24 mo postoperatively. This report deals with findings related to the prosthetic tip. Only one of 136 flow studies were abnormal and only two of 136 blood-pool images demonstrated focally increased activity. All 25 prostheses (120 of 143 scans) demonstrated increased uptake on the bone phase images. The area about the tip was divided into three segments; increased uptake at 24 mo was noted in the medial, distal, and lateral segments in 16%, 72%, and 56% of prostheses, respectively. Twenty of 25 prostheses (82 of 142 scans) showed uptake on In-WBC scintigraphy, being noted in 48% of prostheses at 24 mo. We conclude that scintigraphic patterns in the uncomplicated patient with a porous coated prosthesis appear to differ from patterns described in cemented prostheses.

The acetabulum: a prospective study of three-phase bone and indium white blood cell scintigraphy following porous-coated hip arthroplasty.

Although few studies address the use of three-phase bone scanning (TPBS) and indium-111-labeled white blood cell scintigraphy (111In-WBC) in hip arthroplasty utilizing a porous-coated prosthesis, the literature suggests that scintigraphic patterns in the uncomplicated patient may differ form that seen with the cemented prosthesis. In an attempt to determine the scintigraphic natural history, 25 uncomplicated porous-coated hip arthroplasties in 21 patients were prospectively studied with serial TPBS and 111In-WBC at approximately 7 days, and 3, 6, 12, 18, and 24 mo postoperatively. This report deals with findings related to the acetabulum. All 25 prostheses (144 of 144 scans) demonstrated increased uptake on the bone-phase images. Although this activity decreased with time, 76% had persistent uptake at 24 mo. Twenty-three of 25 prostheses (126 of 140 scans) showed increased uptake on 111In-WBC scintigraphy, invariably decreasing with time, but with 37% having significant uptake at 24 mo. Scintigraphic patterns in the uncomplicated porous-coated hip arthroplasty patient appear to differ from patterns described in cemented prostheses.

Adaptive finite element modeling of long-term polyethylene wear in total hip arthroplasty.

Adaptive remeshing capability was added to an existing sliding-distance-coupled finite element model of polyethylene wear in total hip arthroplasty. This augmentation allowed earlier postoperative wear simulation to be extended to the clinically more significant long-term regimen (as long as 20 years). Loads and femoral head excursions were taken from a physically validated gait analysis model of a patient with an instrumented total hip replacement. For otherwise identical 22, 28, and 32 mm components, the least volumetric wear but the most linear wear occurred for the 22 mm head. When the polyethylene thickness in a 22 mm component was reduced to the same as that in a 32 mm component, the volumetric wear rate for the 22 mm component was still much less than that for the larger component, indicating that sliding distance (head size), rather than polyethylene liner thickness, was primarily responsible for the difference in rates. A "28 mm" series, for which head sizes were varied across the range of currently accepted industrial tolerances, showed that although initial wear rates were greatest for the least congruent articulations, the long-term volumetric wear was nearly the same, regardless of initial clearance.

Prediction of long-term polyethylene wear in total hip arthroplasty, based on early wear measurements made using digital image analysis.

The capability to reliably predict long-term in vivo wear of polyethylene would be of great value for the early identification of problematic total hip designs. Formal quantitative estimates of long-term polyethylene wear were made from a series of 197 patients who had a total hip arthroplasty and who were followed for a minimum of 10 years; the estimates were based on the wear that was apparent radiographically at nominally 2 years after the operation. A newly developed digital image-analysis edge-detection procedure was applied to 1,237 archived follow-up radiographs. The edge-detection measurements were analyzed with a robust regression random-coefficients statistical formulation developed especially to address the distributions of wear rate observed across this population over time. Formal regression equations were reported, which can be used to estimate late-wear depth for a patient radiographed at a 2-year follow-up visit. Series wide, the correlation between predicted and observed wear depths was 0.73 at 4 years, with a correlation decline of approximately 0.03 per additional year.

Revision of total hip arthroplasty in octogenarians.

Twenty-seven revision total hip arthroplasties were performed in patients who were at least eighty years old. The average duration of follow-up was five years. There were no perioperative deaths, and only 11 per cent (three) of the patients had a major complication; all of the complications resolved. The only re-revision was the placement of an extended lip-liner for the treatment of recurrent dislocation. Of the twenty-five patients who were alive at the time of the most recent follow-up or who had been survived by a family member who could be interviewed, twenty-one (84 per cent) said that the operation had improved function, twenty-three (92 per cent) had less pain, and twenty-two (88 per cent) were satisfied with the result.

Revision total hip arthroplasty with cement after cup arthroplasty. Long-term follow-up.

Ninety-six cup arthroplasties (eighty-three patients) were converted to total hip arthroplasties with cement between July 1970 and August 1982. Fifty-eight hips (fifty patients) were followed for at least ten years, or to failure after a shorter interval, and eight other hips (eight patients) had a subsequent operation because of a deep infection. Of the fifty-eight hips that were followed for at least ten years or to failure, nine (16 per cent) were revised because of aseptic loosening of the acetabular component, one (2 per cent) was revised because of a traumatic fracture of the femur, and none were revised because of loosening of the femoral component. Kaplan-Meier survivorship analysis with revision for any reason (including infection) as the end point showed a rate of survival of 92 +/- 6 per cent (average and 95 per cent confidence interval) at ten years and of 74 +/- 12 per cent at twenty years. When the hips in which an infection had occurred were excluded, and with revision because of aseptic loosening of the acetabular component as the end point, the rate of survival was 84 +/- 10 per cent at twenty years; no acetabular component was revised because of aseptic loosening in the first ten years. When the hips in which an infection had occurred were excluded, and with radiographic evidence of definite or probable loosening of the acetabular component, or aseptic loosening of the acetabular component necessitating revision, as the end point, the rate of survival was 91 +/- 6 per cent at ten years and 53 +/- 22 per cent at twenty years. The present study demonstrates the durability of total hip replacement with cement after the failure of a cup arthroplasty and further substantiates the excellent long-term clinical and radiographic results that can be obtained with insertion of a femoral component with cement.

The uncemented porous-coated anatomic total hip prosthesis. Two-year results of a prospective consecutive series.

Fifty uncemented porous-coated total hip prostheses were implanted in forty-seven patients whose mean age was fifty-eight years. Clinical hip-rating scores, as described by Harris, were determined and anteroposterior and frog-leg lateral radiographs were made preoperatively, shortly postoperatively, and at three months, six months, one year, and two years postoperatively. The mean hip-rating score was 92 points (range, (range, 74 to 100 points) at one year and 92 points (range, 69 to 100 points) at two years. The thigh was slightly painful in nine patients (18 per cent) at one year and in eight (16 per cent) at two years. Fourteen hips (28 per cent) (in thirteen patients) caused a moderate or severe limp two years postoperatively; however, this complication appears to have been related more to the direct lateral approach that was used than to the prosthesis. Six (13 per cent) of the patients walked with a cane at one year and five (11 per cent) still required a cane at two years. Serial radiographic evaluations revealed that, between the first and second postoperative years, a progressive radiodense femoral line developed in twenty hips (41 per cent); a progressive acetabular line, in four hips (8 per cent); and progressive femoral sclerosis, in twelve hips (24 per cent). There was progressive loosening of beads from twelve (24 per cent) of the femoral components and from nine (18 per cent) of the acetabular components. The position of one acetabular and one femoral component changed. Two femoral shafts fractured, one intraoperatively and one fourteen months postoperatively. We concluded that the clinical results were encouraging in these patients at the end of two years. We are concerned, however, about the progressive radiodense lines, sclerosis, and loosening of beads as well as the slight, but persistent, pain in the thigh in eight patients.

Hip arthrodesis. A long-term follow-up.

In a retrospective study, we examined twenty-eight patients who had had an arthrodesis seventeen to fifty years previously (average, thirty-five years). Hip and knee ratings were obtained, as well as anteroposterior and flexion-extension radiographs of the lumbar spine and standing anteroposterior radiographs of the knees and hips. About 60 per cent of the patients had pain in the ipsilateral knee (average time to onset, twenty-three years after arthrodesis), and a similar percentage had back pain (average time to onset, twenty-five years after the operation). Pain in the contralateral hip occurred in approximately 25 per cent of the patients (average time to onset, twenty years after arthrodesis). Only one patient was unemployed due to disabling pain in the back or knee. Seventy per cent of the patients could walk more than one mile (1.6 kilometers), and a similar percentage could sit comfortably for at least two hours. Seventy-five per cent of the patients had anteroposterior laxity of the ipsilateral knee, and 80 per cent had mediolateral laxity. The patients whose hip was fused in some abduction more frequently had pain in the ipsilateral knee and the back, and they had greater degenerative changes in the ipsilateral knee than the patients whose hip was fused in adduction or in the neutral position. Six patients had undergone total hip arthroplasty for pain in the back or the ipsilateral knee, or both, and all had marked relief of back pain, while two of four had relief of pain in the knee. Two patients had a total knee arthroplasty for relief of pain in the ipsilateral knee.