Background: Bone graft augmentation is often selected to treat defects associated with unstable tibial plateau fractures. This prospective, randomized, multicenter study was undertaken to determine the efficacy of bioresorbable calcium phosphate cement compared with standard autogenous iliac bone graft in the treatment of these osseous defects.

Methods: One hundred and twenty acute, closed, unstable tibial plateau fractures (Schatzker types I through VI) in 119 adult patients were prospectively enrolled in twelve study sites in North America between 1999 and 2002. Randomization for the type of grafting of the subarticular defect was done at the time of surgery, with use of a 2:1 ratio, to treatment with calcium phosphate cement (eighty-two fractures) or autogenous iliac bone graft (thirty-eight fractures). After open reduction, standard plate-and-screw or screw-only fixation was used and then either the cement or the bone graft was placed in the defect cavity for subarticular support. Follow-up included standard radiographs, evaluated by multiple reviewers to avoid bias, and knee range-of-motion assessment at six months to one year or later.

Results: The age, weight, height, and sex of the patients and the fracture patterns were comparable in the two groups, as were union rates and time to union. There was a significantly (p = 0.009) higher rate of articular subsidence during the three to twelve-month follow-up period in the bone graft group.

Conclusions: The bioresorbable calcium phosphate cement used in this study appears to be a better choice, at least in terms of the prevention of subsidence, than autogenous iliac bone graft for the treatment of subarticular defects associated with unstable tibial plateau fractures.

Level of Evidence: Therapeutic Level I. See Instructions to Authors for a complete description of levels of evidence.

Background: Lumbosacral corsets and braces have been used to treat a variety of spinal disorders. Although their use after lumbar arthrodesis for degenerative conditions has been reported, there is a lack of evidence on which to base guidelines on their use. The purpose of this study was to evaluate the effect of a postoperative corset on the outcome of lumbar arthrodesis.

Methods: A prospective randomized trial was performed in which patients who wore a postoperative lumbar corset for eight weeks full-time after a posterior lumbar arthrodesis for a degenerative spinal condition were compared with those who did not use a corset after such an operation. Ninety patients were randomized to one of the two treatments. A history was recorded and patients were assessed with a physical examination, radiographs, and functional outcome questionnaires (the Dallas Pain Questionnaire [DPQ] and the Short Form-36 [SF-36]) preoperatively and at one year and two years following the surgery. The primary outcome measure of the study was the DPQ, a disease-specific patient-derived functional measure of the spine, and secondary end points included the SF-36 scores, complications, rates of fusion as determined radiographically, and reoperation rates.

Results: Follow-up analysis was performed for seventy-two patients, thirty-seven randomized to the brace (experimental) group and thirty-five randomized to the control group. Regardless of the treatment method, the patients had substantial improvement in the disease-specific and general health measures by two years postoperatively. At two years, there was no difference in the DPQ category scores (the primary outcome parameter) of the two treatment groups. There was also no difference in the mean SF-36 component scores at two years. Postoperative complications occurred in 22% and 23% of patients in the experimental and control groups, respectively, and a subsequent lumbar spinal operation was performed in 19% and 14%, respectively. Seven patients (five in the experimental group and two in the control group) with radiographic evidence of nonunion underwent revision surgery.

Conclusions: This study does not indicate a significant advantage or disadvantage to the use of a postoperative lumbar corset following spinal arthrodesis for degenerative conditions of the lumbar spine.

Level of Evidence: Therapeutic Level I. See Instructions to Authors for a complete description of levels of evidence.

Background: Objective measures to quantitate the amount of lateral compartment opening for patients with lateral and posterolateral knee injuries have not been well documented. The purpose of the present study was to measure lateral compartment opening secondary to applied varus stresses following posterolateral corner structure sectioning and to develop radiographic guidelines to quantify the amount of lateral compartment gapping seen with these injuries.

Methods: Ten nonpaired fresh-frozen cadaver lower extremities were used. Two varus loads, a 12-Nm moment and a clinician-applied varus stress, were applied to the intact knees and after sequential sectioning of the fibular collateral ligament, popliteus tendon, popliteofibular ligament, and anterior and posterior cruciate ligaments to simulate degrees of posterolateral knee and associated combined cruciate ligament injuries. The shortest distance between the most distal subchondral bone surface of the lateral femoral condyle and the corresponding lateral tibial plateau was measured to quantify lateral compartment opening and was analyzed on digital radiographs. Three observers were used to determine interobserver reproducibility and intraobserver repeatability.

Results: In the intact knee, the mean lateral compartment gapping due to a 12-Nm moment and a clinician-applied varus stress was 8.9 and 9.7 mm, respectively. Lateral gapping significantly increased by 2.1 and 2.7 mm in association with sectioning of the fibular collateral ligament and by 3.4 and 4.0 mm in knees with a simulated posterolateral corner injury for each respective load-application technique (p < 0.0001 for all comparisons). Intraobserver repeatability was high, with all observers independently obtaining an intraclass correlation coefficient of 0.99, whereas the analysis of interobserver reproducibility demonstrated an intraclass correlation coefficient of 0.97.

Conclusions: Measurements with use of current clinical digital imaging systems can be used to quantify the amount of lateral compartment knee opening. Clinicians should suspect an isolated fibular collateral ligament injury if opening on clinician-applied varus stress radiographs increases by approximately 2.7 mm and a grade-III posterolateral corner injury if values increase by approximately 4.0 mm.

Clinical Relevance: Varus stress radiographs appear to provide an objective and reproducible measure of lateral compartment gapping that should prove useful for the diagnosis, management, and postoperative follow-up of patients with fibular collateral ligament and posterolateral knee injuries.

Background: The surgical outcomes in patients with scoliosis at two years following anterior thoracoscopic spinal in-strumentation and fusion have been reported. The purpose of this study was to evaluate the results at five years.

Methods: A consecutive series of forty-one patients with major thoracic scoliosis treated with anterior thoracoscopic spinal instrumentation was evaluated at regular intervals. Prospectively collected data included patient demographics, radiographic measurements, clinical deformity measures, pulmonary function, an assessment of intervertebral fusion, and the scores on the Scoliosis Research Society (SRS-24) outcomes instrument. Perioperative and postoperative complications were recorded. Patient data for the preoperative, two-year, and five-year postoperative time points were compared. In addition, a univariate analysis compared selected two-year radiographic, pulmonary function, and SRS-24 data of the study cohort and those of the patients lost to follow-up.

Results: Twenty-five (61%) of the original forty-one patients had five-year follow-up data and were included in the analysis. Between the two-year and five-year follow-up visits, no significant changes were observed with regard to the average percent correction of the major Cobb angle (56% ± 11% and 52% ± 14%, respectively), average total lung capacity as a percent of the predicted value (95% ± 14% and 91% ± 10%), and the average total SRS-24 score (4.2 ± 0.4 and 4.1 ± 0.7). Radiographic evaluation of intervertebral fusion at five years revealed convincing evidence of a fusion with remodeling and trabeculae present at 151 (97%) of the 155 instrumented motion segments. No postoperative infections or clinically relevant neurovascular complications were observed. Rod failure occurred in three patients, and three patients required a surgical revision with posterior spinal instrumentation and fusion.

Conclusions: Thoracoscopic anterior instrumentation for main thoracic idiopathic scoliosis results in five-year outcomes comparable with those reported previously for open anterior and posterior techniques. The radiographic findings, pulmonary function, and clinical measures remain stable between the two and five-year follow-up time points. Thoracoscopic instrumentation provides a viable alternative to treat spinal deformity; however, the risks of pseudarthrosis, hardware failure, and surgical revision should be considered along with the advantages of limited muscular dissection and improved scar appearance.

Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

Background: Substantial differences between disability and impairment are commonplace and puzzling. Subjective (psychosocial) factors may be paramount given that pain is a more important determinant of perceived overall arm-specific disability than is objective elbow impairment. To further evaluate the relationship between impairment and disability, we tested the hypothesis that objective loss of elbow motion predicts perceived elbow-related task-specific disability better than does pain after elbow trauma.

Methods: One hundred and fifty-eight patients were evaluated at a median of twenty-six months after a traumatic elbow injury and completed the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire. Predictors of the total DASH score and of the scores for individual DASH items that were expected to be related to elbow function were evaluated with univariate and multivariate analyses.

Results: Motion accounted for 35% of the variability in the total DASH score, for 11% to 12% of the variability in the responses to questions specific to hand-based activities, and for 24% to 33% of the variability in the scores for tasks depending on elbow motion. Pain accounted for 41% of the variability in the total DASH score and was a better predictor than motion of disability associated with three tasks: opening a tight jar (with pain and motion accounting for 24% and 11% of the variability, respectively), pushing open a door (25% and 12%, respectively), and placing an object overhead (28% and 25%, respectively). None of the multivariate models explained more than 53% of the variability in the DASH scores.

Conclusions: Objective physical elbow impairment correlated with self-reported disability with respect to specific tasks, but a large proportion of disability remains unexplained. Further research is needed to better understand the differences between objective impairment and perceived disability.

Background: Computer navigation systems generally establish the rotational alignment axis of the femoral component on the basis of user-defined anatomic landmarks. However, navigation systems can also record knee kinematics and average alignment axes established with multiple techniques. We hypothesized that establishing femoral rotational alignment with the use of kinematic techniques is more accurate and precise (repeatable) than the use of anatomic techniques and that establishing femoral rotational alignment by averaging the results of different alignment techniques is more accurate and precise than the use of a single technique.

Methods: Twelve orthopaedic surgeons used three anatomic and two kinematic alignment techniques to establish femoral rotational alignment axes in a series of nine cadaver knees. The axes derived with the individual anatomic and kinematic techniques as well as the axes derived with six combination techniques—i.e., those involving averaging of the alignments established with two of the individual techniques—were compared against a reference axis established with computed tomography images of each femur.

Results: The kinematic methods were not more accurate (did not have smaller mean errors) or more precise (repeatable) than the anatomic techniques. The combination techniques were accurate (five of the six had a mean error of <5°) and significantly more precise than all but one of the single methods. The percentage of measurements with <5° of error as compared with the reference epicondylar axis was 37% for the individual anatomic techniques, 30% for the individual kinematic techniques, and 58% for the combination techniques.

Conclusions: Averaging the results of kinematic and anatomic techniques, which is possible with computer navigation systems, appears to improve the accuracy of rotational alignment of the femoral component. The number of rotational alignment outliers was reduced when combination techniques were used; however, they are still a problem and continued improvement in methods to accurately establish rotation of the femoral component in total knee arthroplasty is needed.

Background: Previous studies have demonstrated varying correlations between Workers' Compensation status and the outcome of rotator cuff repair. However, none of those studies have formally accounted for potential confounding factors with multivariable analysis. We hypothesized that patients with Workers' Compensation claims who undergo rotator cuff repair have worse outcomes, even after controlling for confounding factors.

Methods: One hundred and twenty-five patients (including thirty-nine with Workers' Compensation claims) who underwent unilateral primary repair of a chronic rotator cuff tear by a single surgeon were studied prospectively and were evaluated one year postoperatively, prior to the settlement of any claims. Outcomes were assessed with the Simple Shoulder Test (SST); the Disabilities of the Arm, Shoulder and Hand (DASH) index; three visual analog scales (shoulder pain, shoulder function, and quality of life); and the Short Form-36 (SF-36).

Results: Patients in the Workers' Compensation group were significantly younger, had greater work demands, and had lower marital rates, education levels, and preoperative expectations for the outcome of treatment as compared with those in the non-Workers' Compensation group (p = 0.001 to 0.016). Preoperatively, patients in the Workers' Compensation group had significantly lower scores on the SST, the SF-36 Physical Function scale, and the SF-36 Social Function scale (p = 0.01 to 0.038). One year postoperatively, those patients reported worse performance on the SST, the DASH, all three visual analog scales, and the SF-36 (p = 0.0007 to 0.05) and had worse improvement on the DASH, the visual analog scales for shoulder pain and function, and the SF-36 Bodily Pain and Role Emotional scales (p = 0.0028 to 0.038). Multivariable analysis controlling for age, sex, comorbidities, smoking, marital status, education, duration of symptoms, work demands, expectations, and tear size confirmed that Workers' Compensation status was an independent predictor of worse DASH scores.

Conclusions: Patients with Workers' Compensation claims report worse outcomes, even after controlling for confounding factors. The present study provides further evidence that the existence of a Workers' Compensation claim portends a less robust outcome following rotator cuff repair.

Level of Evidence: Prognostic Level I. See Instructions to Authors for a complete description of levels of evidence.

Background: Chronic pelvic instability is a relatively uncommon cause of pelvic and low-back pain. Patients present with feelings of instability and mechanical symptoms. Static radiographs are often inadequate to detect abnormal relative motion between the hemipelves consistent with chronic pelvic instability; dynamic views of the pelvis are required. We assessed the amount of physiologic motion present at the pubic symphysis in normal adult men and nulliparous and multiparous women with alternating-single-leg-stance radiographs.

Methods: Forty-five asymptomatic adult volunteers (fifteen in each group) were evaluated with a standing anteroposterior pelvic radiograph as well as with anteroposterior pelvic radiographs made with the subjects assuming both right and left single-leg stance. The subjects completed a questionnaire to determine their eligibility for participation in the study, and an examination was performed to exclude certain physical anomalies that might alter the radiographic findings.

Results: The mean total translation (and standard deviation) at the pubic symphysis, as measured by three blinded observers, was 1.4 ± 1.0, 1.6 ± 0.8, and 3.1 ± 1.5 mm for the men, nulliparous women, and multiparous women, respectively. With the numbers available, we found no significant difference between the translation in the men and that in the nulliparous women (p = 0.63). The multiparous women had significantly more translation than did either the nulliparous women (p = 0.002) or the men (p = 0.0005). There was a significant positive association between the number of pregnancies and the total translation (p < 0.0001).

Conclusions: The use of anteroposterior pelvic radiographs made with the subject alternating between right and left single-leg stance demonstrated, with high interobserver reliability, that multiparous women had a significantly different physiologic range of pubic translation as compared with men and nulliparous women. The ranges of physiologic motion at the pubic symphysis measured on the single-leg-stance radiographs in this study can be used to identify pathologic amounts of motion at this site.

Clinical Relevance: This investigation suggests that up to 5 mm of physiologic motion can occur at the pubic symphysis in asymptomatic individuals, as demonstrated by alternating-single-leg-stance radiographs.

Background: In the nonacute setting, the diagnosis of pelvic instability is difficult. Patients who present with pelvic pain may have underlying instability. The purpose of the present study was to report the effectiveness of single-leg-stance radiographs in the diagnosis of pelvic instability in a consecutive series of patients presenting with pelvic pain.

Methods: Thirty-eight consecutive patients (twenty-four women and fourteen men) ranging in age from eighteen to seventy-eight years who presented with pelvic pain and a history of injury (twenty-seven), childbirth (seven [four primiparous and three multiparous]), or osteopenia (four) were evaluated with a visual analog scale pain score and a standard series of radiographs in an attempt to identify pelvic instability. The average time from the onset of symptoms to the evaluation was forty-one months (range, six weeks to twenty-seven years). Each patient was evaluated with supine anteroposterior, inlet, and outlet pelvic radiographs; a standing anteroposterior pelvic radiograph; and two single-leg-standing pelvic radiographs (one with the patient standing on the left leg and one with the patient standing on the right leg). A positive finding was defined as ≥0.5 cm of vertical translation measured at the symphyseal bodies between the two single-leg-stance radiographs.

Results: Of the thirty-eight patients, twenty-five demonstrated pelvic instability (average, 1.98 cm; range, 0.5 to 5 cm). With the numbers available, the average visual analog scale pain score for the patients with a stable pelvis was not significantly different from that for the patients with an unstable pelvis (6.4 ± 2.9 compared with 7.3 ± 1.9; p = 0.28).

Conclusions: Standing anteroposterior and single-leg-stance pelvic radiographs aid in the diagnosis of pelvic instability more effectively than do the standard three radiographs of the pelvis made in the supine position or a standing anteroposterior radiograph of the pelvis alone. Additional studies will be needed to correlate this instability with clinical symptoms.

Level of Evidence: Diagnostic Level IV. See Instructions to Authors for a complete description of levels of evidence.

Background: Congenital anterolateral bowing of the tibia is a pre-pseudarthrosis stage of congenital pseudarthrosis of the tibia and is associated with a substantial risk of fracture and pseudarthrosis. We evaluated the results of prophylactic bypass grafting performed in combination with bracing to prevent fracture and pseudarthrosis.

Methods: This retrospective series included ten patients with pre-pseudarthrosis of the tibia treated, between 1991 and 2002, with prophylactic bypass grafting with an allograft fibula placed posteromedially in a stress-bearing fashion. The average patient age was 2.3 years at the time of diagnosis, 3.6 years at the time of surgery, and ten years at the time of final follow-up. The mean duration of follow-up was seventy-eight months. Brace protection was recommended at the time of diagnosis and was continued after the operation until maturity. Despite the bracing, a low-energy fracture developed and partially healed prior to the bypass grafting in one patient. The remaining nine patients had no fractures prior to the bypass grafting. At the time of final follow-up, the patients were examined clinically and radiographically for the presence of a fracture or pseudarthrosis and for residual deformity, including malalignment, ankle and knee joint abnormalities, and leg length discrepancy.

Results: No patient had either a fracture or a pseudarthrosis of the tibia at the time of follow-up. All grafts united to the tibia at both ends. Complications included an allograft fracture in three patients, which healed in all; allograft resorption in one patient; and pseudarthrosis of the ipsilateral host fibula in one patient. At the time of final follow-up, a mean of 9 mm (range, 0 to 37 mm) of leg length discrepancy was found. A corrective osteotomy was done for four patients (three because of ankle valgus and one because of diaphyseal deformity).

Conclusions: In this small series of ten patients with congenital anterolateral bowing of the tibia treated with bypass strut grafting and long-term bracing, there were no cases of pseudarthrosis of the tibia. Distal tibial deformity may persist throughout the growth period and require operative correction in patients treated with this procedure.

Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

Background: Compromised vascularity and hypoxia have been proposed as risks for tendon ruptures. The density of vascularity of the quadriceps tendon may explain the pattern of ruptures of this muscle-tendon unit.

Methods: Twenty adult human cadavers underwent whole-body arterial perfusion with a mixture of lead oxide, gelatin, and water through the femoral artery. Thirty-three quadriceps tendons were dissected and radiographed, and each angiogram was analyzed with use of image statistical software.

Results: We consistently identified a hypovascular zone located between 1 and 2 cm from the superior pole of the patella. This finding correlates with the location of spontaneous ruptures of the quadriceps tendon reported in the literature. These findings indicate that the vascular supply of the quadriceps tendon is separated into three arcades, or arches, which are medial, lateral, and peripatellar.

Conclusions: Hypovascularity may determine the site of spontaneous ruptures of the quadriceps tendon.

Clinical Relevance: Understanding the vascular zones of the quadriceps tendon may facilitate the use of nonoperative as well as operative treatments to increase the vascularity of the tendon. An understanding of the vascular arcades may facilitate and enhance healing following reparative and reconstructive surgery on the tendon.

Background: Following hip fracture, pharmacologic treatment can reduce the rate of subsequent fragility fractures. The objective of the present study was to assess the proportion of patients who are managed with bisphosphonates or selective estrogen-receptor modulators after hip fracture and to evaluate, among those managed with alendronate, the twelve-month compliance and persistence with treatment.

Methods: Data were gathered from health insurance companies and were collected by AIM (Agence Intermutualiste) for the Belgian National Social Security Institute (INAMI). We selected all postmenopausal women who had been hospitalized for a hip fracture between April 2001 and June 2004 and had not been previously managed with bisphosphonates. Patients who had received alendronate treatment after the hip fracture were categorized according to their formulation use during the follow-up study (daily, weekly, daily followed by weekly, or weekly followed by weekly). Compliance at twelve months was quantified with use of the medication possession ratio (i.e., the number of days of alendronate supplied during the first year of treatment, divided by 365). Persistence with prescribed treatment was calculated as the number of days from the initial prescription to a lapse of more than five weeks after completion of the previous prescription refill. The cumulative treatment persistence rate was determined with use of Kaplan-Meier survival curves.

Results: A total of 23,146 patients who had sustained a hip fracture were identified. Of these patients, 6% received treatment during the study period: 4.6% received alendronate, 0.7% received risedronate, and 0.7% received raloxifene. Bisphosphonate treatment was dispensed to 2.6% and 3.6% of the patients within six months and one year after the occurrence of the hip fracture, respectively. Among women who received alendronate daily (n = 124) or weekly (n = 182) and were followed for at least one year after the hip fracture, the twelve-month mean medication possession ratio was 67% (65.9% in the daily group and 67.7% in the weekly group). The analysis of persistence with treatment included a total of 726 patients (142 in the daily group, 261 in the weekly group, and 323 in the switch group). At twelve months, the rate of persistence was 41% and the median duration of persistence was 40.3 weeks.

Conclusions: The vast majority of patients who experience a hip fracture do not take anti-osteoporotic therapy after the fracture. Furthermore, among patients who begin alendronate treatment after the fracture, the adherence to treatment decreases over time and remains suboptimal.

Background: The surgical treatment of calcaneal deformity in patients with myelomeningocele has not been uniformly successful in correcting the deformity and preventing recurrence. The purpose of the present study was to examine the results of posterior transfer of the anterior tibial tendon with concurrent procedures in an attempt to balance the muscular forces on the foot and ankle and to obtain a plantigrade foot. We investigated whether surgery improved pressure distribution over the plantar surface of the foot and whether concurrent abnormal movements observed at the knee, hip, and pelvis influenced the surgical outcome.

Methods: Thirty-one feet in eighteen patients who were able to walk were included in the study. The mean age at the time of surgery was seven years and four months, and the mean duration of follow-up was forty-seven months. Eight patients were classified as having an L5-level myelomeningocele, and ten patients were classified as having a sacral level myelomeningocele. A tibialis anterior tendon transfer was performed in all patients, and accompanying osseous deformities were also corrected in twelve feet. Measurements on plain radiographs, the results of gait analyses, and dynamic foot pressures that were determined before surgery and at the time of the final follow-up were compared.

Results: No recurrence or worsening of the deformity was observed in any of the patients, and no other types of foot deformity developed after surgery. Postoperative kinematic studies showed a significant (p < 0.0001) increase in peak plantar flexion and a significant decrease in peak dorsiflexion force of the ankle in the stance phase of gait. Peak pressures under the forefoot and midfoot were increased after surgery, and the relative amount of weight-bearing on the heel as compared with the forefoot was shifted toward more equal weight-bearing. However, less improvement in foot-pressure distribution was observed in patients with increased pelvic rotation before surgery. Those patients also had decreased knee extension in stance phase and increased hip abduction and pelvic obliquity both before and after surgery in comparison with patients who had normal pelvic rotation.

Conclusions: Appropriately combined corrective surgical procedures for the treatment of calcaneal deformity in patients with myelomeningocele can effectively reduce the pressure placed on the calcaneus, increase pressures in the forefoot and midfoot, and prevent recurrence of the calcaneal deformity. However, in the presence of excessive pelvic movement in the coronal and transverse planes and decreased knee extension in stance phase, adequate improvement in pressure distribution over the plantar surface of the foot is not likely to occur after this type of foot surgery.

Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

Background: According to the long-term results obtained from the Scandinavian arthroplasty registries, cemented total hip replacement has been the treatment of choice for osteoarthritis of the hip in elderly patients. The aim of the present study was to analyze population-based survival rates of the cemented and cementless total hip replacements performed for primary osteoarthritis in patients fifty-five years of age or older in Finland.

Methods: From 1980 to 2004, a total of 50,968 primary total hip replacements that met our criteria were entered in the Finnish Arthroplasty Registry. The success rate of different implant groups was analyzed. The implants included were classified in one of the following four groups: implants with a cementless, straight, proximally circumferentially porous-coated stem and a modular, porous-coated press-fit cup (cementless group 1); implants with a cementless, anatomic, proximally circumferentially porous-coated and/or hydroxyapatite-coated stem with a modular, porous-coated and/or hydroxyapatite-coated press-fit cup (cementless group 2); a hybrid total hip replacement consisting of a cemented stem combined with a modular, press-fit cup (the hybrid group); and a cemented loaded-taper or composite-beam stem combined with an all-polyethylene cup (the cemented group).

Results: Cementless total hip replacements, as well as cementless stems and cups analyzed separately, had a significantly reduced risk of revision for aseptic loosening compared with cemented hip replacements (p < 0.001). When revision for any reason was the end point in survival analyses, however, there were no significant differences among the groups. In patients between the ages of fifty-five and sixty-four years, the fifteen-year survival rates of the two cementless groups (78% and 80%) were higher than that of the cemented group (71%) with revision for aseptic loosening as the end point. In patients who were sixty-five to seventy-four years old, the fifteen-year survival rate of the implants in cementless group 1 was 94%, while cemented total hip replacements had an 85% survival rate. In patients who were seventy-five years old or more, no significant differences were detected among the total hip replacement groups; all of them had survivorship of >90% at ten years.

Conclusions: In patients who were fifty-five years of age or older, the long-term survival of cementless total hip replacements was comparable with that of cemented replacements. In patients who were fifty-five to seventy-four years old, straight porous-coated cementless stems had better long-term survival than the cemented stems. In patients who were seventy-five years of age and older, there were no significant differences in the results. Multiple wear-related revisions of the cementless cups in the present study indicate that excessive polyethylene wear was a major clinical problem with modular cementless cups in all age groups.

Level of Evidence: Therapeutic Level III. See Instructions to Authors for a complete description of levels of evidence.

Background: Persistent muscle imbalance and soft-tissue contractures can lead to progressive glenohumeral joint dysplasia in patients with brachial plexus birth palsy. The objective of the present investigation was to determine the effects of tendon transfers and open glenohumeral reduction on shoulder function and dysplasia in patients with preexisting joint deformity secondary to brachial plexus birth palsy.

Methods: Twenty-three patients with preexisting glenohumeral deformity underwent latissimus dorsi and teres major tendon transfers to the rotator cuff with concomitant musculotendinous lengthening of the pectoralis major and/or subscapularis and open glenohumeral joint reduction for the treatment of internal rotation contracture and external rotation weakness. Shoulder function was assessed with use of the modified Mallet classification system and the Active Movement Scale. Glenoid version and humeral head subluxation were quantified radiographically, and glenohumeral deformity was appropriately graded. The mean duration of clinical and radiographic follow-up was thirty-one and twenty-five months, respectively.

Results: Clinically, all patients demonstrated improved global shoulder function, with the mean aggregate Mallet score improving from 10 points preoperatively to 18 points postoperatively (p < 0.01). The mean modified Mallet score for external rotation improved from 2 to 4 (p < 0.01). Similarly, the mean Active Movement Scale score for external rotation improved from 3 to 6 (p < 0.01). The mean Mallet hand-to-spine score improved from 1 to 2 (p < 0.01). The mean Active Movement Scale score for internal rotation remained constant at 6. Radiographically, the mean glenoid version improved from –39° preoperatively to –18° postoperatively (p < 0.01). The mean percentage of the humeral head anterior to the middle of the glenoid similarly improved from 13% to 38% (p < 0.01). The mean glenohumeral deformity score improved from 3 to 2 (p < 0.01). Nineteen (83%) of the twenty-three patients demonstrated glenohumeral remodeling; one patient had progressive worsening of glenohumeral deformity.

Conclusions: Tendon transfers to the rotator cuff, combined with musculotendinous lengthenings and open reduction of the glenohumeral joint, improve global shoulder function and lead to glenohumeral joint remodeling in the majority of selected patients with mild-to-moderate preexisting glenohumeral dysplasia secondary to brachial plexus birth palsy. Future study of the long-term outcomes of these procedures will help to clarify the ultimate effect on glenohumeral joint function.

Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

Background: Loosening of a cemented glenoid component is an important cause of failure in shoulder arthroplasty. This study was developed to examine the outcome of patients managed with a metal-backed, bone-ingrowth glenoid component as an alternative to a cemented component.

Methods: The study group included eighty-three total shoulder arthroplasties with a metal-backed, bone-ingrowth glenoid component performed between 1989 and 1994. Seventy-four shoulders had a diagnosis of primary osteoarthritis, and nine shoulders had other diagnoses. All patients were followed radiographically and clinically for a minimum of two years or until the time of revision surgery. Kaplan-Meier survival estimates were performed with revision and/or radiographic failure as the end points.

Results: The mean clinical follow-up was 9.5 years, and the mean radiographic follow-up was 7.1 years. Pain ratings (on a scale of 1 to 5) decreased from a mean of 4.7 preoperatively to 2.0 postoperatively. The mean range of motion in active elevation increased from 102° preoperatively to 135° postoperatively; the mean external rotation increased from 27° to 56°. Glenohumeral joint instability developed in fourteen shoulders. Radiographic changes consistent with glenoid component loosening were present in thirty-three shoulders. Polyethylene wear with metal wear of the glenoid component was noted in twenty-one shoulders, and humeral component loosening was seen in fifteen shoulders. Revision procedures were performed in twenty-six shoulders. There were no identifiable patient, disease, or surgical characteristics associated with failure, either clinically or radiographically. The five-year survival estimate free of revision or radiographic failure was 79.9% (95% confidence interval, 71.6% to 89.3%), and the ten-year survival estimate was 51.9% (95% confidence interval, 41.0% to 65.8%).

Conclusions: The high rate of failure of total shoulder arthroplasties performed with this metal-backed, bone-ingrowth glenoid component raises concerns as to its use, and perhaps the use of other types of metal-backed components, in shoulder arthroplasty, other than for special situations.

Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

Background: Implant loosening is associated with inflammatory bone loss induced by ultra-high molecular weight polyethylene wear debris. We hypothesized that a hydroxyapatite-bisphosphonate composite improves periprosthetic bone quality and osseous integration of an intramedullary implant even in the presence of ultra-high molecular weight polyethylene particles in an experimental rat femur model.

Methods: A preliminary in vitro study determined the optimal concentration of zoledronate (50 µM) that would maximally decrease osteoclasts without harming osteoblasts. Hydroxyapatite-coated intramedullary nails were implanted bilaterally in the femora of sixteen rats (the control group), and hydroxyapatite-zoledronate-coated nails were implanted bilaterally in the femora of sixteen rats (the experimental group). Ultra-high molecular weight polyethylene particles were introduced into the femoral canal before implantation. Eight rats from each group were killed at six weeks, and the remaining rats were killed at six months. Periprosthetic bone mass was analyzed by dual x-ray absorptiometry and microcomputed tomography. Osseous integration was examined by biomechanical testing of pullout strength.

Results: The mean bone area (and standard deviation) in the periprosthetic bone region was significantly greater (p < 0.0001) in the hydroxyapatite-zoledronate group (2.388 ± 0.960 mm²) than in the control group (0.933 ± 0.571 mm²). This difference was larger in the six-week group than in the six-month group (p = 0.03). The average peak pullout force for the treated femora (241.0 ± 95.1 N) was significantly greater (p < 0.0001) than that for the controls (55.6 ± 49.0 N). This difference was similar in the six-week and six-month groups. The energy required for nail pullout was significantly greater (p < 0.0001) for the treated femora (521.6 ± 293.8 N-mm) than for the controls (142.2 ± 152.1 N-mm). This difference in energy to pullout was similar in the six-week and six-month groups. Regression analysis demonstrated a high correlation between periprosthetic bone mass and peak pullout force for both the six-week (r = 0.766, p = 0.0005) and six-month (r = 0.838, p < 0.0001) groups.

Conclusions: Surface modification of implants with hydroxyapatite-zoledronate improves periprosthetic bone quality and osseous integration.

Clinical Relevance: Hydroxyapatite-based site-specific delivery of bisphosphonates may be one way of reducing ultra-high molecular weight polyethylene wear particle-induced periprosthetic osteolysis and implant loosening.

Background: The best surgical treatment for a patient with rheumatoid arthritis and an acute distal humeral fracture is not well established. Because of the distorted anatomy of the arthritic elbow joint and the adjacent osteoporotic bone, total elbow arthroplasty may be favored over open reduction and internal fixation in these patients. We retrospectively analyzed a series of patients with rheumatoid arthritis in whom an acute distal humeral fracture had been treated with either open reduction and internal fixation or total elbow arthroplasty; our purpose was to evaluate their outcomes and to identify any influence of age, fracture type, or the extent of the rheumatoid involvement of the elbow joint on the choice of procedure.

Methods: Between 1982 and 2002, an acute distal humeral fracture was treated surgically in sixteen elbows in fourteen patients with rheumatoid arthritis, and the results were retrospectively reviewed at a minimum of twenty-four months postoperatively. Six elbows were treated with open reduction and internal fixation (Group 1) and ten elbows, with primary total elbow arthroplasty (Group 2). Postoperatively, the elbows were examined with standard radiographs, and the clinical outcome was assessed with the Mayo Elbow Performance Score (MEPS).

Results: Six patients (six elbows) died before the time of the study, but they had been followed for more than twenty-four months and therefore were included in the series. The eight patients (ten elbows) who were still alive were examined. The mean duration of follow-up was forty-nine months in Group 1 and sixty-six months in Group 2. The MEPS averaged 93 points in Group 1 and 96 points in Group 2. Radiographically, all fractures had healed uneventfully in Group 1 and no prosthesis was loose in Group 2. We could not identify any difference between Groups 1 and 2 with respect to patient age, fracture type, or extent of the rheumatoid arthritis.

Conclusions: Distal humeral fractures in patients with rheumatoid arthritis can be treated successfully with immediate open reduction and internal fixation or with total elbow arthroplasty. Our data suggest that open reduction and internal fixation can be successful when there is mild arthritic involvement. We favor total elbow arthroplasty for patients with severe articular involvement.

Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

Background: The success rate of rotator cuff repairs is variable. This study was performed to evaluate the ability of recombinant human bone morphogenetic protein-12 (rhBMP-12), administered in several carriers, to accelerate healing in a sheep model of rotator cuff repair.

Methods: Local retention of tracer amounts of radiolabeled rhBMP-12, added to non-radiolabeled rhBMP-12 delivered in buffer, hyaluronan paste or sponges, or Type-I or Type-I/III collagen sponges was first evaluated with use of gamma scintigraphy in a pilot study of a rat intramuscular implant model. The rhBMP-12/paste and sponge combinations were then evaluated in eight sheep each with unilateral complete detachment and subsequent double-row reattachment of the infraspinatus tendon to the proximal part of the humerus. Contralateral, normal shoulders from sixteen sheep and shoulders in which a repair had been done without administration of rhBMP-12 in fourteen sheep were also evaluated. The rhBMP-12/Type-I and Type-I/III collagen sponge combinations were each evaluated in eight additional sheep on the basis of superior efficacy. The Type-I/III collagen sponge alone was evaluated in ten sheep to examine the effect of a collagen carrier. Ultrasound imaging was performed at four and eight weeks. Radiographic evaluation, mechanical testing, and biochemical evaluation were performed at eight weeks. Histological evaluation was performed on specimens from the sites of selected repairs following mechanical testing.

Results: The sponge carriers had longer local retention of rhBMP-12 than did the buffer or paste carriers in the rat models. All of the sheep shoulder-repair groups demonstrated ultrasound evidence of a gap between the tendon and the humeral insertion. The gap length and the cross-sectional area of the repair tissue decreased with time. The mechanical properties of the repairs treated with rhBMP-12 and hyaluronan paste were similar to those of the untreated repairs. The maximum loads for the rhBMP-12/hyaluronan sponge and rhBMP-12/collagen sponge-treated repairs were 2.1 and 2.7 times greater, respectively, than the loads for the untreated repairs and were 33% and 42% of the value for the normal tendon at eight weeks. The maximum loads for the repairs treated with rhBMP-12 and a Type-I or Type-I/III collagen sponge were 2.1 times greater than those for the repairs treated with the Type-I/III collagen sponge alone. Changes in maximum stiffness followed a similar pattern. Histological evaluation demonstrated accelerated healing of the rhBMP-12-treated repairs compared with the untreated repairs. Bone formation was observed in all repairs, and biochemical measurements were not equivalent to those of normal tendon at eight weeks.

Conclusions: Delivery of rhBMP-12 in a collagen or hyaluronan sponge resulted in accelerated healing of acute full-thickness rotator cuff repairs in a sheep model.

Clinical Relevance: Delivery of rhBMP-12 in several sponge carriers has the potential to accelerate healing of rotator cuff repairs. Accelerated repair may allow shorter rehabilitation and an earlier return to occupational and recreational activities.

Background: We examined the hypothesis that thrombophilia, hypofibrinolysis, and the endothelial nitric oxide synthase (eNOS) T-786C polymorphism are common, potentially treatable, and similar pathophysiologic causes of multifocal (three sites or more) and unifocal (single-site) osteonecrosis.

Methods: We prospectively evaluated twenty-six consecutively referred adults with multifocal osteonecrosis, who included thirteen with idiopathic multifocal osteonecrosis and thirteen with secondary multifocal osteonecrosis (resulting from steroid therapy in ten and alcoholism in three). We compared these patients with race, sex, and age-matched normal control subjects and with patients with idiopathic unifocal and secondary unifocal osteonecrosis, respectively. Using polymerase chain reaction and serologic measures, we studied thrombophilic and hypofibrinolytic mutations and the eNOS T-786C polymorphism.

Results: The total number of polymerase chain reaction and serologic thrombophilic-hypofibrinolytic abnormalities and the eNOS T-786C polymorphism did not differ between patients with idiopathic (p > 0.5) or secondary (p > 0.5) multifocal and unifocal osteonecrosis. The frequency of low free protein-S levels (<66%) in patients with secondary multifocal osteonecrosis (four of eleven patients) was higher than that in the control subjects (one of fifty-nine) (risk ratio = 21.5; 95% confidence interval, 2.6 to 174; p = 0.0016, Benjamini-Hochberg adjusted p [Bp] = 0.004). Factor-V Leiden heterozygosity was present in two of thirteen patients with secondary multifocal osteonecrosis compared with none of sixty-four control subjects (p = 0.027, Bp = 0.008). For eleven patients with secondary multifocal osteonecrosis, the eNOS T-786C polymorphism was present in nine of twenty-two alleles compared with eight of forty-four alleles in twenty-two normal control subjects (risk ratio = 2.3; 95% confidence interval, 1.0 to 5.0; p = 0.047, Bp = 0.016). The frequency of homocystinemia (>13.5 µmol/L) was higher in patients with idiopathic multifocal osteonecrosis (two of thirteen patients) than in normal controls (none of fifty-one) (p = 0.039, Bp = 0.004). A high level of factor VIII (>150%) was seen in four of eight patients with idiopathic multifocal osteonecrosis and in seven of forty-eight normal controls (risk ratio = 3.4; 95% confidence interval, 1.3 to 9.1; p = 0.04, Bp = 0.008). The eNOS T-786C mutant allele was present in seven of twelve alleles in the six patients with idiopathic multifocal osteonecrosis who were tested, compared with twenty-five of 108 alleles in fifty-four control subjects (risk ratio = 2.5; 95% confidence interval, 1.4 to 4.5; p = 0.015, Bp = 0.008).

Conclusions: Limited by the small numbers of patients with multifocal osteonecrosis, this exploratory study suggested that thrombophilia was associated with both idiopathic multifocal osteonecrosis and secondary multifocal osteonecrosis, as was the eNOS T-786C polymorphism. Multifocal and unifocal osteonecrosis are similarly associated with thrombophilia, hypofibrinolysis, and the eNOS T-786C polymorphism, which are potentially treatable pathophysiologic conditions, requiring further study.

Demand for total joint arthroplasty is projected to increase in the first three decades of the twenty-first century.

With increasing frequency, patients who have a hip or knee replacement expect to, and choose to, participate in athletics following rehabilitation.

In general, patients who have had a hip or knee replacement decrease their participation in, and intensity of, athletic activity following the total joint arthroplasty.

The orthopaedic literature on athletic activity after total joint arthroplasty is limited to small retrospective studies with short-term follow-up.

Expert opinion regarding appropriate athletic activity after total joint arthroplasty is available from the Hip Society and the Knee Society.

When patients who have undergone joint replacements choose to participate in athletic activity, orthopaedic surgeons should provide information with which to evaluate the risk of sports activity and recommend appropriate athletic activity.

Background: The amount of time devoted to musculoskeletal medicine in the typical undergraduate curriculum is disproportionately low compared with the frequency of musculoskeletal complaints that occur in a general practice. Consequently, whether because of the quantity or quality of the education, the competence level of graduating physicians regarding musculoskeletal problems is inadequate. Our purposes were to design a self-contained, system-based course in musculoskeletal medicine for medical students in the preclinical years and to measure the level of competence achieved by a class of first-year medical students who took the course.

Methods: The course was formulated by faculty from the departments of orthopaedic surgery, anatomy, and rheumatology and included elements of both objectives-based and problem-centered curricular models. The clinical lectures were preceded by pertinent anatomy lectures and dissections to provide a context for the clinical information. The lectures on basic science were designed to rationalize and explicate clinical practices. Small-group activities were incorporated to permit engagement of the students in critical thinking and problem-solving. A general musculoskeletal physical examination was taught in two two-hour-long small-group sessions with the orthopaedic residents serving as instructors. Cognitive competency was evaluated with use of comprehensive anatomy laboratory and written examinations, the latter of which included a validated basic competency examination in musculoskeletal medicine. Process-based skills were evaluated in the small-group meetings and in a timed, mock patient encounter in which each student's ability to perform the general musculoskeletal physical examination was assessed.

Results: The course lasted six weeks and consisted of forty-four lecture hours, seventeen hours of small-group meetings, and twenty-eight hours of anatomy laboratory. The average student score on the basic competency examination was 77.8%, compared with 59.6% for a historical comparison group (p < 0.05). Each student demonstrated the ability to adequately perform a general musculoskeletal physical examination in twenty minutes. The survey of student opinion after the course indicated a high level of student satisfaction.

Conclusions: The main features of the course were: (1) an emphasis on both cognitive and process-based knowledge; (2) more contact hours and broader content than in previously described courses in musculoskeletal medicine; (3) the use of small groups to focus on problem-solving and physical examination competencies; (4) basic-science content directly related to clinical goals. These features might be used at other institutions that employ a system-based curriculum for the preclinical years to help improve competence in musculoskeletal medicine.