Mark R. Brinker

Use of an osteoinductive biomaterial (rhOP-1) in healing large segmental bone defects.

OBJECTIVE To assess the radiographic, histologic, and mechanical characteristics of new bone formation in large segmental bone defects treated with a new osteoconductive material, recombinant human osteogenic protein-1 (rhOP-1). DESIGN In vivo animal study. INTERVENTION Sixteen dogs (thirty-two limbs) with an ulna segmental defect (2.5 centimeters) were randomized to three treatment groups: rhOP-1, collagen alone, and no implant. MAIN OUTCOME MEASUREMENTS Radiographic evidence of defect healing, mechanical testing (torsional strength) as compared with thirty-one control intact dog ulnas, and histologic analysis. RESULTS At twelve weeks, complete radiographic healing was observed in twenty-five of twenty-eight defects (89 percent) treated with rhOP-1. The mechanical strength of the rhOP-1-treated defects at twelve weeks was 65 percent of that of intact ulnas. Histologic analysis revealed that defects treated with rhOP-1 were bridged with lamellar and woven bone that was in continuity with the host bone. CONCLUSIONS The results indicate that osteoinductive materials, which have the ability to quickly fill and heal large defects, may have advantages over osteoconductive materials, which are typically used to fill smaller non-load-bearing bone voids.

A method for open reduction and internal fixation of the unstable posterior sternoclavicular joint dislocation.

Posterior sternoclavicular joint (SCJ) dislocations are most often stable after reduction but may be associated with significant complications related to the location of the medial head of the clavicle within the mediastinum. In rare instances, a posterior SCJ dislocation is irreducible or redislocates after a closed reduction. Because of the potential hazards related to compression of vital structures within the superior mediastinum, open reduction and internal fixation is usually required. Although open reduction is widely accepted as the method of choice, the best method for achieving stable fixation remains unanswered. We present the case of an unstable SCJ stabilized, in anatomic position, with two large-bore cannulated screws in conjunction with open reduction. We believe that the risk of hardware migration reported with the use of pins and wires and its catastrophic complications are greatly minimized using our technique.

Clinical and roentgenographic evaluation of noncemented porous-coated anatomic medullary locking (AML) and porous-coated anatomic (PCA) total hip arthroplasties.

Eighty-four primary noncemented porous-coated total hip arthroplasties (THAs) in 78 patients were reviewed clinically and roentgenographically at an average follow-up period of 37 months. The average patient age was 51.9 years. Sixty-four Anatomic Medullary Locking (AML) devices were placed in 58 patients, and 20 Porous-Coated Anatomic (PCA) devices were placed in 20 patients. The AML devices had been in situ an average of 36 months (range, 24-49 months), and the PCA devices had been in situ an average of 40 months (range, 29-51 months). The average patient ages were 52.7 and 49.2 years for AML and PCA patients, respectively. The AML devices included three that were fully coated, 59 that were five-eighths coated, and two that were one-third coated. The average preoperative Harris hip score was 38.2 for the AML devices and 33.2 for the PCA devices. The average postoperative Harris hip score was 80.7 for the AML devices and 83.8 for the PCA devices. Pain related to the implant was present in 30% of the AML devices and 30% of the PCA devices. Roentgenographically, no component demonstrated complete radiolucency, and all components demonstrated roentgenographic evidence of bone ingrowth. Roentgenographic changes with time noted for both the AML and PCA devices included: neck roundoff, neck osteolysis, neck corticocancellization, endosteal bone bridging, and distal hypertrophy. On roentgenographic zonal analysis, radiolucency greater than 1 mm was observed most frequently in the most proximal lateral zone and distal tip of the femoral component. The current series of cases, although clinically acceptable, does not support the current widespread enthusiasm for primary noncemented AML and PCA total hip systems. Cemented THA appears to produce superior clinical results, particularly when contemporary cementing techniques are employed.

Comparison of General and Epidural Anesthesia in Patients Undergoing Primary Unilateral THR

One hundred ninety-five consecutive patients underwent 195 primary unilateral total hip arthroplasties between January 1988 and December 1993. Patients were divided into three groups based on the type of anesthesia utilized for their procedure. Group I consisted of 108 patients (59 women and 49 men; average age 56 years) who had general endotracheal anesthesia alone. Group II consisted of 70 patients (41 women and 29 men, average age 58 years) who had general endotracheal anesthesia with epidural augmentation intraoperatively and postoperatively. Group III consisted of 17 patients (6 women and 11 men, average age 62 years) who had epidural anesthesia only. Data were analyzed by anesthesia group to compare a variety of clinically relevant factors. No statistically significant differences among groups were noted regarding average age at surgery, the underlying diagnoses leading to joint replacement, the number of preexisting medical conditions, length of hospitalization, nonsurgical operating room time, intraoperative blood transfusions, intraoperative femur fractures, deep venous thrombosis, deep infections, death, or the prevalence of postoperative urinary tract infections. Postoperative urinary tract infections correlated with duration of Foley catheterization, but not the duration of epidural catheterization. Significant differences among anesthesia groups were observed for two factors: 1) estimated intraoperative blood loss was highest for Group I (P < .05) and was primarily a function of surgical time (P < .0001), and 2) postoperative Hemovac output (over the first and second postoperative 24-hour periods) was greatest for Group II (P < .05). Epidural anesthesia appears to be a safe modality in patients undergoing primary unilateral total hip replacement.

Early changes in nutrient artery blood flow following tibial nailing with and without reaming: a preliminary study.

OBJECTIVE To quantify the changes in nutrient artery blood flow following reamed and unreamed nailing of intact canine tibias. DESIGN In vivo animal study. INTERVENTION Eighteen dogs underwent nutrient artery blood flow measurements over a fourteen-day period. The intervention groups consisted of controls (Group I), nailing without reaming (Group II), and nailing with reaming (Group III). MAIN OUTCOME MEASUREMENTS Nutrient artery blood flow was measured through implantable ultrasonic blood flow probes placed around the nutrient artery of the tibia. RESULTS Nutrient artery blood flow averaged 1.94 milliliters per minute over the fourteen-day period in Group I (no reaming or nailing performed). Nutrient artery blood flow following nailing without reaming (Group II) decreased to 44 percent of baseline values immediately after the procedure. By postoperative day 1, flow had decreased to 23 percent of baseline; over the fourteen-day period, nutrient artery blood flow recovered toward baseline values. Immediately following nailing with reaming (Group III), nutrient artery blood flow measured zero milliliters per minute. Over the fourteen-day period, nutrient artery blood flow in this group averaged 39 percent of the baseline level (range 19 to 58 percent). Whereas nutrient artery blood flow recovered toward baseline values (99 percent of baseline) by fourteen days in Group II, nutrient artery blood flow measured only 26 percent of the baseline level on postoperative day fourteen in Group III. CONCLUSIONS The preliminary data suggest that nailing with reaming provides a double insult to the nutrient artery distribution.

Pseudo-dislocation of the sternoclavicular joint.

Fractures of the medial third of the clavicle are the rarest of all clavicle fractures. We present two cases of medial clavicle fracture nonunions that were initially thought to be chronic anterior sternoclavicular dislocations and describe the entity of pseudo-dislocation of the sternoclavicular joint. Computed tomography should be performed on all patients with suspected or established injuries of the sternoclavicular region to ensure differentiation between fracture and dislocation.

Utilization of orthopaedic services in a capitated population.

Background: The utilization rate for orthopaedic services (office visits and surgery) is not well known. The purpose of this study was to determine the utilization rates for orthopaedic office visits and surgical procedures in a large population of captured lives.Methods: The study population comprised an average of 134,902 persons per month who were enrolled under a capitated insurance plan between January 1999 and December 1999. This plan was serviced by an independent physician association of sixty-two orthopaedic surgeons who were responsible for all orthopaedic care. Data were collected prospectively and stored in a centralized database. All analyses were conducted with use of monthly averages. Poisson regression was used to compare utilization rates and to calculate odds ratios in order to determine whether the utilization rates varied by age and gender.Results: The highest proportions of office visits were due to fractures (21%), osteoarthritis (4%), meniscal tears (4%), and low-back pain or sciatica (4%). Knee arthroscopy (30%), foot and ankle procedures (10%), and spine procedures (9%) accounted for the highest proportions of surgical procedures. The overall utilization rates were 6.96 office visits and 1.99 surgical procedures per 1000 covered lives per month. Across all age groups, males and females did not differ with respect to the utilization rate for office visits (p = 0.42) or surgery (p = 0.09). Increased age was significantly related to increased utilization rates for office visits (p £ 0.0002) and surgery (p ⩽ 0.002).Conclusions: These data may be used to determine the size of a capitated population that an orthopaedic practice can accommodate, to determine the number of orthopaedic providers that is needed to provide services for a capitated population, and to estimate the expenses associated with providing orthopaedic services for a capitated population in an orthopaedic practice.

Percutaneous autologous bone marrow injection in the treatment of distal meta-diaphyseal tibial nonunions and delayed unions.

Objective: To report the outcomes of percutaneous autologous bone marrow injection for nonunion or delayed union of the distal tibial metaphysis in patients with prior plating. Design: Consecutive case series. Setting: Tertiary center. Patients: Eleven consecutive patients (aged 24–51 years) were referred to us with a nonunion or delayed union of the distal tibial metaphysis after open reduction and internal fixation (plates and screws) at the time of fracture. The average time from initial injury to nonunion or delayed union and bone marrow treatment was 8 months (range, 3–20 months). Intervention: A total of 40–80 mL of bone marrow aspirated from the posterior iliac crest and injected in and around the nonunion or delayed union site under fluoroscopic guidance. Measurements: Healing at the injury site was evaluated using clinical and radiographic criteria, including computed tomography. Measures included American Academy of Orthopaedic Surgeons Lower Limb Core Scale (LLCS), Brief Pain Inventory, and Short Form 12 Physical Component Summary. Results: Nine of the 11 patients attained bony union within 6 months of bone marrow injection. Six of these 9 patients who were followed-up an average of 4.4 years (range, 1.3–8.2 years) after the injection reported significant (P < 0.05) improvements in Lower Limb Core Scale (59.9–89.7), pain intensity (2.9–1.7), pain interference (4.6–2.3), and Short Form 12 Physical Component Summary (29.5–46.6) and 5.6 years improvement in quality-adjusted life years. Conclusions: Percutaneous autologous bone marrow injection is a minimally invasive, safe, and inexpensive treatment option for distal metaphyseal tibial nonunions or delayed unions after internal fixation and should be considered when the retained hardware seems to be intact and stable. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Quality and outcome determination in health care and orthopaedics: evolution and current structure.

&NA; Quality health care has many definitions. Among those definitions is “care that consistently contributes to the improvement or maintenance of the quality and/or duration of life.” The current evolution in health care has been fueled by three necessities frequently demanded by payers and employers: improvement in access, lowering of cost, and definition and quantification of the quality of care. This evolution has been facilitated by the so‐called industrialization of medicine. This concept includes the adoption of industrial economic principles and techniques that facilitate the measurement of processes and outcomes. Quality health care is currently recognized as health care that is characterized by three elements: the use of practice guidelines or standards, the implementation of continuous quality improvement techniques, and the use of outcome determination and management. Practice guidelines demand the adoption of evidence‐based principles in evaluation and care, as well as minimization of variations in evaluation and care. Continuous quality improvement seeks to determine why variations in processes of care occur and then to minimize those variations. Outcomes may be measured in terms of both very objective and very subjective variables and also on the basis of cost‐efficiency. Most tools currently used to quantify outcomes, especially in orthopaedics, involve measurements of general health and of specific body part or organ system function. This evolution in health care is producing significant alterations in methods of traditional health‐care delivery. The accumulating evidence indicates that these changes, although frequently unpopular, are improving the quality of health care.

Development of a method to analyze orthopaedic practice expenses.

The purpose of the current investigation was to present a standard method by which an orthopaedic practice can analyze its practice expenses. To accomplish this, a five-step process was developed to analyze practice expenses using a modified version of activity-based costing. In this method, general ledger expenses were assigned to 17 activities that encompass all the tasks and processes typically performed in an orthopaedic practice. These 17 activities were identified in a practice expense study conducted for the American Academy of Orthopaedic Surgeons. To calculate the cost of each activity, financial data were used from a group of 19 orthopaedic surgeons in Houston, Texas. The activities that consumed the largest portion of the employee work force (person hours) were service patients in office (25.0% of all person hours), maintain medical records (13.6% of all person hours), and resolve collection disputes and rebill charges (12.3% of all person hours). The activities that comprised the largest portion of the total expenses were maintain facility (21.4%), service patients in office (16.0%), and sustain business by managing and coordinating practice (13.8%). The five-step process of analyzing practice expenses was relatively easy to perform and it may be used reliably by most orthopaedic practices.