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.

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.

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.

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.

The revision acetabulum--allograft and bone substitutes: vestigial organs for bone deficiency.

A common situation presenting to the orthopaedic surgeon today is a worn acetabular liner with substantial acetabular and pelvic osteolysis. The surgeon has many options for dealing with osteolytic defects. These include allograft, calcium based substitutes, demineralised bone matrix, or combinations of these options with or without addition of platelet rich plasma. To date there are no clinical studies to determine the efficacy of using bone-stimulating materials in osteolytic defects at the time of revision surgery and there are surprisingly few studies demonstrating the clinical efficacy of these treatment options. Even when radiographs appear to demonstrate incorporation of graft material CT studies have shown that incorporation is incomplete. The surgeon, in choosing a graft material for a surgical procedure must take into account the efficacy, safety, cost and convenience of that material.

Surgical challenges and clinical outcomes of total hip replacement in patients with Down's syndrome.

Down's syndrome is associated with a number of musculoskeletal abnormalities, some of which predispose patients to early symptomatic arthritis of the hip. The purpose of the present study was to review the general and hip-specific factors potentially compromising total hip replacement (THR) in patients with Down's syndrome, as well as to summarise both the surgical techniques that may anticipate the potential adverse impact of these factors and the clinical results reported to date. A search of the literature was performed, and the findings further informed by the authors' clinical experience, as well as that of the hip replacement in Down Syndrome study group. The general factors identified include a high incidence of ligamentous laxity, as well as associated muscle hypotonia and gait abnormalities. Hip-specific factors include: a high incidence of hip dysplasia, as well as a number of other acetabular, femoral and combined femoroacetabular anatomical variations. Four studies encompassing 42 hips, which reported the clinical outcomes of THR in patients with Down's syndrome, were identified. All patients were successfully treated with standard acetabular and femoral components. The use of supplementary acetabular screw fixation to enhance component stability was frequently reported. The use of constrained liners to treat intra-operative instability occurred in eight hips. Survival rates of between 81% and 100% at a mean follow-up of 105 months (6 to 292) are encouraging. Overall, while THR in patients with Down's syndrome does present some unique challenges, the overall clinical results are good, providing these patients with reliable pain relief and good function.

Subcapital fractures: a changing paradigm.

Options for the treatment of subcapital femoral neck fractures basically fall into two categories: internal fixation or arthroplasty (either hemiarthroplasty or total hip arthroplasty). Historically, the treatment option has been driven by a diagnosis-related approach (non-displaced neck fractures versus displaced neck fractures). More recently, the traditional paradigm has changed. Instead of a diagnosis-related approach, it has become more of a patient-related approach. Treatment options take in to consideration the patient's age, functional demands, and individual risk profile. A simple algorithm can be helpful in terms of directing the treatment. Non-displaced fractures, regardless of age of the patient, should be treated with closed reduction and internal fixation. For displaced femoral neck fractures, the treatment differs depending on the age of the patient. The younger patient should be treated with urgent ORIF with the goal of an anatomic reduction. For displaced femoral neck fractures in the elderly, cognitive function should be determined. For those who are cognitively functioning, total hip arthroplasty appears to be the best option. In the cognitively dysfunctional, a bipolar hemiarthroplasty or a total hip arthroplasty with use of larger heads (32 mm or 36 mm) and/or constrained sockets are a viable option.

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.

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.

Comparison of femoral head penetration rates between cementless acetabular components with 22-mm and 28-mm heads.

Between April 1993 and July 1994, the senior author (R.C.J.) performed 151 consecutive primary total hip arthroplasties using a Harris-Galante II acetabular component and a polished Iowa femoral component. In 105 hips, 22-mm head components were used, and in 46 hips, 28-mm head components were used. Femoral head penetration into the acetabular shell was measured using digital edge detection techniques. The group average penetration for the initial 2-year bedding-in period was 0.35 mm/y for the 22-mm and 0.31 mm/y for the 28-mm head components. The long-term rate of penetration into the shell was 0.11 mm/y for the 22-mm heads and 0.17 mm/y for the 28-mm heads, a significant difference (P=.029). The dislocation rate was significantly higher, however, with the 22-mm heads (P=.001). The 22-mm components showed significantly less wear but at the expense of an increase in the prevalence of dislocation.

Impaction allografting with cement for extensive femoral bone loss in revision hip surgery: a 4- to 8-year follow-up study.

The current study evaluates the 4- to 8-year results of 26 cemented femoral revisions with impaction allografting using a collared femoral component in cases of extensive femoral bone loss. Patients were followed prospectively and were evaluated at an average of 6.0 years after the allograft revision procedure. The average age at the time of surgery was 69.3 years. At final follow-up, 20 patients (20 hips) were living, and 6 patients (6 hips) were deceased. No femoral component rerevisions were performed for any reason in any patient, and none were radiographically loose at final follow-up. There was 1 subsided femoral component of <5 mm, 3 postoperative periprosthetic femoral fractures, and a greater trochanter nonunion rate of 32%. At the current follow-up interval, these cemented femoral revisions with impaction allografting have performed well with excellent clinical and radiographic durability in this difficult patient population. The prevalence of periprosthetic fracture is a significant concern. This study shows durable results using the impaction allografting technique in cases of severe bone loss.

Charnley total hip arthroplasty with use of improved cementing techniques: a minimum twenty-year follow-up study.

BACKGROUND: In total hip arthroplasty, techniques for cementing the femoral component have changed over time. The purpose of the present study was to determine whether a cementing technique that includes use of a distal cement plug and retrograde filling of the femoral canal affects the fixation of the femoral component at a minimum of twenty years after the operation. METHODS: Between 1976 and 1978, the senior one of us (R.C.J.) performed 357 total hip arthroplasties with use of a Charnley flatback polished femoral stem and a contemporary cementing technique (insertion of a distal cement plug and retrograde filling of the femoral canal with cement) in 320 patients. The results after a minimum follow-up of twenty years were compared with those after 330 total hip arthroplasties performed, between 1970 and 1972, with the same femoral stem by the same surgeon with use of a hand-packing technique of cementing in 262 patients. The clinical and radiographic evaluation as well as the duration of follow-up were identical in the two groups. RESULTS: In the group managed with the contemporary cementing technique, six (1.8%) of the 336 hips that had not been lost to follow-up or revised because of infection or dislocation were revised because of aseptic loosening of the femoral component. Of the ninety-one hips in the eighty-two patients who were alive at a minimum of twenty years, five (5%) had a revision because of aseptic loosening of the femoral component. Only one hip was revised during the fifteen-to-twenty-year follow-up interval. (The revision was performed because of a fracture of the femoral component.) The rate of failure when radiographic signs of loosening were included was 4.8% (sixteen of 336 femoral components that had not been revised because of infection or dislocation) for the group managed with the contemporary cementing technique compared with 6.3% (twenty of 319 hips) in the group managed with the hand-packing technique; the difference was not significant (p = 0.40). Adequate filling of the femoral canal with cement was found to be associated with improved survival of the femoral component (p = 0.03). CONCLUSIONS: While no significant difference between the two cementing techniques could be identified, the ability to deliver adequate cement around the femoral component was more predictable with the contemporary cementing technique. In addition, the prevalence of loosening of the femoral component was low with use of either technique, a tribute to the Charnley flatback polished femoral component design.