Michael P. Kelly

Future Young Patient Demand for Primary and Revision Joint Replacement: National Projections from 2010 to 2030

AbstractPrevious projections of total joint replacement (TJR) volume have not quantified demand for TJR surgery in young patients (<xa065xa0years old). We developed projections for demand of TJR for the young patient population in the United States. The Nationwide Inpatient Sample was used to identify primary and revision TJRs between 1993 and 2006, as a function of age, gender, race, and census region. Surgery prevalence was modeled using Poisson regression, allowing for different rates for each population subgroup over time. If the historical growth trajectory of joint replacement surgeries continues, demand for primary THA and TKA among patients less than 65xa0years old was projected to exceed 50% of THA and TKA patients of all ages by 2011 and 2016, respectively. Patients less than 65xa0years old were projected to exceed 50% of the revision TKA patient population by 2011. This study underscores the major contribution that young patients may play in the future demand for primary and revision TJR surgery.n Level of Evidence: Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Bisphosphonates and Fractures of the Subtrochanteric or Diaphyseal Femur

BACKGROUNDnA number of recent case reports and series have identified a subgroup of atypical fractures of the femoral shaft associated with bisphosphonate use. A population-based study did not support this association. Such a relationship has not been examined in randomized trials.nnnMETHODSnWe performed secondary analyses using the results of three large, randomized bisphosphonate trials: the Fracture Intervention Trial (FIT), the FIT Long-Term Extension (FLEX) trial, and the Health Outcomes and Reduced Incidence with Zoledronic Acid Once Yearly (HORIZON) Pivotal Fracture Trial (PFT). We reviewed fracture records and radiographs (when available) from all hip and femur fractures to identify those below the lesser trochanter and above the distal metaphyseal flare (subtrochanteric and diaphyseal femur fractures) and to assess atypical features. We calculated the relative hazards for subtrochanteric and diaphyseal fractures for each study.nnnRESULTSnWe reviewed 284 records for hip or femur fractures among 14,195 women in these trials. A total of 12 fractures in 10 patients were classified as occurring in the subtrochanteric or diaphyseal femur, a combined rate of 2.3 per 10,000 patient-years. As compared with placebo, the relative hazard was 1.03 (95% confidence interval [CI], 0.06 to 16.46) for alendronate use in the FIT trial, 1.50 (95% CI, 0.25 to 9.00) for zoledronic acid use in the HORIZON-PFT trial, and 1.33 (95% CI, 0.12 to 14.67) for continued alendronate use in the FLEX trial. Although increases in risk were not significant, confidence intervals were wide.nnnCONCLUSIONSnThe occurrence of fracture of the subtrochanteric or diaphyseal femur was very rare, even among women who had been treated with bisphosphonates for as long as 10 years. There was no significant increase in risk associated with bisphosphonate use, but the study was underpowered for definitive conclusions.

Impact of Relational Coordination on Quality of Care, Postoperative Pain and Functioning, and Length of Stay: A Nine-hospital Study of Surgical Patients

BACKGROUNDnHealth care organizations face pressures from patients to improve the quality of care and clinical outcomes, as well as pressures from managed care to do so more efficiently. Coordination, the management of task interdependencies, is one way that health care organizations have attempted to meet these conflicting demands.nnnOBJECTIVESnThe objectives of this study were to introduce the concept of relational coordination and to determine its impact on the quality of care, postoperative pain and functioning, and the length of stay for patients undergoing an elective surgical procedure. Relational coordination comprises frequent, timely, accurate communication, as well as problem-solving, shared goals, shared knowledge, and mutual respect among health care providers.nnnRESEARCH DESIGNnRelational coordination was measured by a cross-sectional questionnaire of health care providers. Quality of care was measured by a cross-sectional postoperative questionnaire of total hip and knee arthroplasty patients. On the same questionnaire, postoperative pain and functioning were measured by the WOMAC osteoarthritis instrument. Length of stay was measured from individual patient hospital records.nnnSUBJECTSnThe subjects for this study were 338 care providers and 878 patients who completed questionnaires from 9 hospitals in Boston, MA, New York, NY, and Dallas, TX, between July and December 1997.nnnMEASURESnQuality of care, postoperative pain and functioning, and length of acute hospital stay.nnnRESULTSnRelational coordination varied significantly between sites, ranging from 3.86 to 4.22 (P <0.001). Quality of care was significantly improved by relational coordination (P <0.001) and each of its dimensions. Postoperative pain was significantly reduced by relational coordination (P = 0.041), whereas postoperative functioning was significantly improved by several dimensions of relational coordination, including the frequency of communication (P = 0.044), the strength of shared goals (P = 0.035), and the degree of mutual respect (P = 0.030) among care providers. Length of stay was significantly shortened (53.77%, P <0.001) by relational coordination and each of its dimensions.nnnCONCLUSIONSnRelational coordination across health care providers is associated with improved quality of care, reduced postoperative pain, and decreased lengths of hospital stay for patients undergoing total joint arthroplasty. These findings support the design of formal practices to strengthen communication and relationships among key caregivers on surgical units.

The Total Condylar Prosthesis

Forty knees with total condylar prostheses have been followed for ten years or more. There were five failures, one due to infection and four directly related to either improper selection or technical reasons. Thirty-five knees (87.5%) have a satisfactorily functioning arthroplasty after ten years. There were no loose components and no complete radiolucent lines. Technique and correct alignment are most important and, provided that the operation is correctly performed, conventional polymethyl methacrylate cement fixation is completely adequate. The absence of progressive adverse radiologic changes suggests that knee arthroplasties have a considerable life expectancy.

Osteoporosis and Vitamin-D Deficiency Among Postmenopausal Women with Osteoarthritis Undergoing Total Hip Arthroplasty

BACKGROUNDnSeveral epidemiological studies have shown a lower prevalence of osteoporotic hip fractures in patients with osteoarthritis. Other studies have demonstrated elevated bone mineral density in patients with osteoarthritis. The prevailing view is that there may be an inverse relationship between osteoarthritis and osteoporosis. The purposes of the present study were to describe a subgroup of patients with osteoarthritis who were found to have osteoporosis and to assess the vitamin-D status and other risk factors for low bone density in osteoarthritic subjects with and without osteoporosis.nnnMETHODSnThe bone mineral density of the spine, the proximal part of the femur, and the total body was measured with dual-energy x-ray absorptiometry in sixty-eight postmenopausal white women who were scheduled to undergo total hip replacement for advanced osteoarthritis. The serum levels of 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, intact parathyroid hormone, osteocalcin, and bone-specific alkaline phosphatase and the urinary level of N-telopeptide were measured. Information from validated lifestyle, dietary, and demographic questionnaires was also evaluated.nnnRESULTSnSeventeen (25%) of the sixty-eight women had occult osteoporosis (as indicated by a T score of less than -2.5). Fifteen (22%) of the sixty-eight subjects had vitamin-D deficiency, and three (4%) had an elevated serum parathyroid hormone level. Only two of the seventeen osteoporotic women had vitamin-D deficiency. On the basis of these numbers, vitamin-D status was not correlated with bone density (p = 0.32). Analysis of the relationship between the number of years since menopause and osteoporosis or markers of elevated bone turnover showed that osteoporosis was detected throughout the postmenopausal period.nnnCONCLUSIONnA substantial portion of these sixty-eight white women with osteoarthritis of the hip had occult osteoporosis and hypovitaminosis D. Vitamin-D deficiency was not restricted to the group with low bone density. These results support the need to consider the presence of both osteoporosis and vitamin-D deficiency in women with advanced osteoarthritis.

Adjacent Segment Motion After Anterior Cervical Discectomy and Fusion Versus ProDisc-C Cervical Total Disk Arthroplasty : Analysis from a Randomized, Controlled Trial

Study Design. Post hoc analysis of data acquired in a prospective, randomized, controlled trial. Objective. To compare adjacent segment motion after anterior cervical discectomy and fusion (ACDF) versus cervical total disc arthroplasty (TDA). Summary of Background Data. TDA has been designed to be a motion-preserving device, thus theoretically normalizing adjacent segment kinematics. Clinical studies with short-term follow-up have yet to demonstrate a consistent significant difference in the incidence of adjacent segment disease. Methods. Two hundred nine patients at 13 sites were treated in a prospective, randomized, controlled trial of ACDF versus TDA for single-level symptomatic cervical degenerative disc disease (SCDD). Flexion and extension radiographs were obtained at all follow-up visits. Changes in ROM were compared using the Wilcoxon signed-rank test and the Mann-Whitney U test. Predictors of postoperative ROM were determined by multivariate analysis using mixed effects linear regression. Results. Data for 199 patients were available with 24-month follow-up. The groups were similar with respect to baseline demographics. A significant increase in motion at the cranial and caudal adjacent segments after surgery was observed in the ACDF group only (cranial: ACDF: +1.4° (0.4, 2.4), P = 0.01; TDA: +0.8°, (−0.1, +1.7), P = 0.166; caudal: ACDF: +2.6° (1.3, 3.9), P < 0.0001; TDA: +1.3, (−0.2, +2.8), P = 0.359). No significant difference in adjacent segment ROM was observed between ACDF and TDA. Only time was a significant predictor of postoperative ROM at both the cranial and caudal adjacent segments. Conclusion. Adjacent segment kinematics may be altered after ACDF and TDA. Multivariate analysis showed time to be a significant predictor of changes in adjacent segment ROM. No association between the treatment chosen (ACDF vs. TDA) and ROM was observed. Furthermore clinical follow-up is needed to determine whether possible differences in adjacent segment motion affect the prevalence of adjacent segment disease in the two groups.

The risk of adjacent-level ossification development after surgery in the cervical spine: are there factors that affect the risk? A systematic review.

Study Design. Systematic review. Objective. To answer the following clinical questions: (1) What is the risk of adjacent-level ossification development (ALOD) in patients receiving noninstrumented cervical fusion, instrumented cervical fusion with a plate, or cervical total disc arthroplasty?; (2) What are the risk factors for ALOD?; (3) What is the time course for the development of ALOD?; and (4) Does ALOD affect outcomes and rates of reoperation? Summary of Background Data. Anterior cervical plating, total disc arthroplasty, and noninstrumented fusion have all been used in the treatment of cervical disc disease. There are numerous reports that identify ALOD, a form of heterotopic ossification, as a major risk factor after performing these procedures. Few studies have compared these 3 procedures to evaluate the risk, timing, and outcomes related to postoperation ALOD. Methods. A systematic search was conducted in PubMed and the Cochrane Library for articles published between January 1, 1990, and December 31, 2011. We included all articles that described the risk of or risk factors for ALOD after surgical treatment of the cervical spine. Studies with patients older than 18 years or those treated for tumor or trauma were excluded from the study. In addition, those with posterior fusions, case reports, and case series with less than 10 patients were excluded. Results. A total of 5 studies met the inclusion criteria for our systematic review. The risk of ALOD with anterior cervical discectomy and fusion ranged from 41% to 64%, whereas the risk of ALOD after total disc replacement ranged from 6% to 24%. When ALOD did occur, there was a 2-fold higher risk of development at the cranial adjacent segment. The most important risk factor for the development of ALOD was the use of instrumentation and the plate-to-disc distance, although the surgical procedure type (corpectomy vs. discectomy and fusion) neared but did not reach statistical significance. Insufficient evidence was available to delineate the time course for its development and how ALOD affected outcomes. Conclusion. The current body of literature suggests that ALOD will develop with the use of instrumentation and especially so if anterior instrumentation is placed within 5 mm of the adjacent cranial disc segment. In addition, total disc replacement showed lower rates for the development of ALOD compared with anterior cervical discectomy and fusion at both short- and long-term follow-up. Consensus Statement We recommend that the surgeon make every effort to keep the plate as far away from the adjacent disc as possible. Strength of Statement: Strong

Pedicle subtraction osteotomy in the cervical spine.

Study Design. Description of surgical technique with review of literature. Objective. To describe the surgical management of cervical spine deformity, using pedicle subtraction osteotomy. Summary of Background Data. Previous articles have primarily described Smith-Petersen osteotomies and Simmons modifications to correct fixed cervical deformity. Those were typically performed with the patient awake and sedated in a seated position and without the use of spinal instrumentation. Methods. Description of a single surgeons technique for performing pedicle subtraction osteotomy to treat fixed cervical deformity. Conclusion. The use of pedicle subtraction osteotomy in the cervical spine is a safe and effective procedure when performed by experienced surgeons and can result in a satisfying outcome for both the patient and the surgeon.

Fate of the adult revision spinal deformity patient: a single institution experience.

Study Design. Retrospective case series. Objective. The aim of this study was to determine the revision rates for all revision spinal deformity (SD) surgical procedures performed at a single center and to investigate the changes in measures of HRQL in these patients. Summary of Background Data. Reported revision rates for primary adult spinal fusion surgical procedures have been in the range of 9% to 45%, but to our knowledge, the revision rate after revision SD surgery has not been reported. The reported improvements in health-related quality of life measures after revision SD surgery have also been quite modest. Methods. Four hundred fifty-five consecutive adult revision SD surgical procedures (1995–2008) were identified and the records were reviewed to determine the reason for and timing to any additional operation(s). Scoliosis Research Society (SRS) Outcome scores were recorded at the first visit and at planned follow-up visits. Results. Ninety-four of 455 patients underwent further surgical procedures for a revision rate of 21%. Two-year follow-up was available for 74 (78%) of these patients (mean follow-up, 6.0 yr; range, 2.4–12.6; sex: F = 61, M = 13; mean age, 53 yr; range, 21–78). The most common causes of revision surgery were pseudarthrosis (N = 23, 31%), implant prominence/pain (N = 15, 20%), adjacent segment disease (N = 14, 19%), and infection (N = 10, 14%). Twenty-five (27%) patients underwent more than one revision procedure. SRS outcome scores were available for 50 (68%) patients, at an average follow-up of 4.9 years (range, 2–11.4). The mean improvements in the SRS outcome measures were as follows: pain, 0.74 (P < 0.001); self-image, 0.8 (P < 0.001); function, 0.5 (P < 0.001); satisfaction, 1.2 (P < 0.001); and mental health, 0.3 (P = 0.012). Conclusion. The rate of revision after revision SD surgery was 21%, most commonly due to pseudarthrosis, adjacent segment disease, infection, and implant prominence/pain. However, significant improvements in SRS outcome scores were still observed in those patients requiring additional revision procedures. Level of Evidence: 4

Dynamic Constructs for Spinal Fusion: An Evidence-Based Review

Dynamic stabilization of the spine has applications in cervical and lumbar degenerative disease and in thoracolumbar trauma. There is little evidence to support the use of dynamic cervical plates rather than rigid anterior cervical fixation. Evidence to support the use of dynamic constructs for fusion in the lumbar spine is also limited. Fusion rates, implant loosening, and failure are significant concerns that limit the adoption of current devices. This article provides a synopsis of the literature on human subjects. There is a need for high-quality evidence for interventions for spinal pathology. An evidence-based approach to the management of spinal disorders will require ongoing assessment of clinical outcomes and comparison of effectiveness between alternatives.