PubMed Health⌕ Search

Biomedical subjects

David J Jacofsky

Publications and source records attributed to David J Jacofsky.

At least 19 recordsLinked to original sources
PubMed2007

Femoral neck fractures in pediatric patients: 30 years experience at a level 1 trauma center.

Femoral neck fractures in children are severe injuries associated with the potentially disastrous complication of femoral head osseous necrosis. Our primary goal was to identify what factors contribute to the occurrence of femoral head osteonecrosis in skeletally immature patients with femoral neck fractures. We evaluated a large consecutive series of pediatric patients with femoral neck fractures. Between 1970 and 2000, 20 patients with a mean age of 11 years (range, 4-15 years) with femoral neck fractures were identified. All traumatic epiphyseal, transcervical, and basicervical (Types I, II, and III) fractures were included. There were 14 male patients and six female patients. The mean followup was 7 years (range, 1-28 years). Timing of surgery, type of fixation, and quality of reduction were analyzed with respect to the primary outcome measure-radiographic evidence of femoral head osteonecrosis. Eighteen of 20 hip fractures healed without complication; all had good or excellent reductions. Two patients had osteonecrosis develop; both had fair or poor reductions. Five patients were treated more than 48 hours after injury, including the two patients who had osteonecrosis develop. The mean time to fixation for the remaining patients was 12 hours. There was no relationship between capsular decompression and osteonecrosis development. Quality of reduction and timing of reduction influenced the risk of osteonecrosis.

Adolescent↗
PubMed2006

Locking plate fixation for proximal humeral fractures: initial results with a new implant.

Treatment of proximal humeral fractures remains controversial, with multiple reported techniques and variable results. Recently, locking plates have become available for fixation of osteopenic and comminuted fractures. This study reports our initial experience with a new locking plate designed specifically for proximal humeral fractures. We observed 16 patients until union or revision with a mean of 12 months' follow-up. Of the 16 patients, 9 had high-energy injuries. There were nine 3-part, five 2-part, and two 4-part fractures. Twelve of sixteen patients healed without complications. There were 4 nonunions; all occurred in patients with 3-part fractures with metadiaphyseal comminution, 3 of whom were heavy smokers. In patients with united fractures, mean elevation was 132 degrees and mean external rotation was 43 degrees, with mean internal rotation to T11. Locking plate fixation achieved union in 75% of patients in this series. Risk factors for delayed union or nonunion included comminution, smoking, and 3-part fractures. These fractures remain challenging despite the availability of locked plating systems.

Adolescent↗
PubMed2006

Electromyographic activity in the immobilized shoulder girdle musculature during scapulothoracic exercises.

OBJECTIVE: To quantify the electromyographic activity in the shoulder girdle musculature during scapulothoracic exercises performed in a shoulder immobilizer in asymptomatic men. DESIGN: Descriptive. SETTING: Motion analysis laboratory at a tertiary care center. PARTICIPANTS: Five asymptomatic male volunteers ages 24 to 32 years. INTERVENTION: Fine-wire (supraspinatus, infraspinatus, upper subscapularis) and surface (deltoids, trapezii, biceps, serratus anterior) electrodes recorded electromyographic activity from each muscle during scapular clock, elevation, depression, protraction, and retraction exercises completed during a single testing session in random order. MAIN OUTCOME MEASURE: Mean peak normalized (percentage of maximal voluntary contraction [MVC]) electromyographic activity of each muscle during each exercise. RESULTS: Biceps activity was uniformly low (<20% MVC), whereas upper subscapularis activity was uniformly high (40%-63% MVC). Both scapular depression and protraction elicited low activity (<20% MVC) in the supraspinatus, infraspinatus, anterior deltoid, and biceps brachii muscles, while generally producing greater than 20% MVC activity in the trapezii and serratus. Scapular depression produced the largest serratus anterior activity (47% MVC). CONCLUSIONS: These data are the first to describe the electromyographic activity during scapulothoracic exercises while in a shoulder immobilizer. Based on electrophysiologic data in normal volunteers, our findings suggest that during periods of shoulder immobilization: (1) scapular depression and protraction exercises could potentially be safely performed after rotator cuff repair to facilitate scapulothoracic rehabilitation, (2) all exercises studied could potentially be safe after superior labral anteroposterior shoulder repair, and (3) all exercises studied should be avoided after subscapularis repair. Further investigation in symptomatic individuals may facilitate refinement of these recommendations.

Adult↗
PubMed2006

Comparative study of antimicrobial release kinetics from polymethylmethacrylate.

Polymethylmethacrylate loaded with antimicrobial agents (most commonly vancomycin and/or aminoglycosides) is used for treatment and prevention of orthopaedic infections. Emergence of organisms resistant to vancomycin or aminoglycosides or both has been reported. Therefore, we studied in vitro release from polymethylmethacrylate beads of antimicrobials with suitable spectra for orthopaedic infections, including cefazolin, ciprofloxacin, gatifloxacin, levofloxacin, linezolid, and rifampin (2.5%, 7.5%, and 15%). Beads were placed in a continuous flow chamber, and antimicrobial concentrations in chamber outflow were determined by bioassay at timed intervals thereafter. Release profiles were bimodal with initial rapid release of high concentrations followed by sustained, slow release. Antimicrobial agents studied showed varied release profiles, indicating that elution from polymethylmethacrylate is unique to individual antimicrobial agents. Increasing antimicrobial concentration in polymethylmethacrylate increased peak concentrations and area under the curve. Cefazolin, ciprofloxacin, gatifloxacin, levofloxacin, linezolid, and rifampin may be suitable for incorporation into polymethylmethacrylate for management of orthopaedic infections.

Acetamides↗
PubMed2006

Intraoperative fractures of the acetabulum during primary total hip arthroplasty.

BACKGROUND: The intraoperative occurrence of an acetabular fracture is a rare complication of primary total hip arthroplasty. Previous reports have lacked a sufficiently large number of subjects to allow for an analysis of the causes and appropriate treatment of this problem. METHODS: Between 1990 and 2000, 7121 primary total hip arthroplasties were performed at our institution. We retrospectively reviewed the records in our Total Joint Registry and found that twenty-one patients (twenty-one hips) had sustained an intraoperative acetabular fracture. Nineteen of these patients (nineteen hips) had been followed until revision or for a minimum of two years (mean duration of follow-up, forty-four months). We evaluated the anatomic location, cause, treatment, and outcome of the fractures. Acetabular component designs were categorized as modular, nonmodular (monoblock), true hemispherical, or elliptical, and then each design was analyzed for fracture risk. RESULTS: No fractures occurred in association with cemented acetabular components. The fracture rate associated with uncemented components was 0.4%. In seventeen hips, the acetabular component was judged to be stable despite the detection of a fracture and the cup was retained. In four hips, the original cup was not stable and therefore was replaced with a design that allowed for supplemental screw fixation. All fractures united, and all cups demonstrated osseous ingrowth at the time of the most recent follow-up. Elliptical monoblock cups were associated with a significantly higher fracture rate than were elliptical modular cups (p < 0.0001) and hemispherical modular cups (p < 0.0001). There was no significant difference between elliptical modular and hemispherical modular components with regard to the fracture rate. CONCLUSIONS: Acetabular fracture during primary total hip arthroplasty is a rare complication of acetabular fixation without cement. In the present series, retention of a stable cup was associated with uneventful osseous ingrowth and excellent early-term outcomes. We found a high rate of fracture in association with the use of monoblock elliptical components. LEVEL OF EVIDENCE: Therapeutic Level III.

Acetabulum↗
PubMed2006

Advances and challenges in diagnosis and management of skeletal metastases.

The treatment of metastatic disease remains challenging. The number of patients who will be diagnosed with metastatic bone disease will continue to increase as survival from the primary cancer diagnosis continues to improve. Although it often is impossible to cure these patients, the task of maximizing their quality of life must be met with valiant efforts. Although a large number of medical and technological advances have occurred, perhaps the recognition of the importance of a well-qualified multidisciplinary team approach to treatment of these complex patients has done more to improve the field than any other single achievement. As basic science continues to further unravel potential treatment options, we must not forget this integrated approach and we must embrace "the bench" at the bedside.

Bone Neoplasms↗
PubMed2005

Daptomycin treatment of Staphylococcus aureus experimental chronic osteomyelitis.

BACKGROUND: Infection due to methicillin-resistant Staphylococcus aureus (MRSA) is increasingly common in nosocomial and community settings. Daptomycin is a cyclic lipopeptide anti-infective with activity against MRSA, approved for treatment of complicated skin and skin structure infections. Daptomycin may be useful in systemic or local treatment of chronic osteomyelitis. METHODS: We measured mechanical strength of daptomycin- and vancomycin-loaded polymethylmethacrylate (PMMA), assayed in vivo release of daptomycin and vancomycin from daptomycin- and vancomycin-loaded PMMA, respectively, and compared the efficacy of two systemic doses of daptomycin with that of vancomycin, each with or without the respective anti-infective loaded into PMMA, using a rat model of MRSA chronic osteomyelitis. RESULTS: Neither tensile nor compressive strength of PMMA was impacted by impregnation with these antimicrobials at a concentration of 7.5% by weight. The peak concentrations of daptomycin and vancomycin in rat tibial bone surrounding a 7.5% daptomycin- and vancomycin-loaded 3 mm PMMA bead were 178 and 49 mg/L, respectively. In the treatment of experimental osteomyelitis, rats assigned to no treatment, daptomycin 50 mg/kg subcutaneously twice daily, daptomycin 60 mg/kg subcutaneously twice daily, and vancomycin 50 mg/kg intraperitoneally twice daily had 6.4, 4.1, 4.0 and 4.5 median log10 cfu/g of bone at the end of 21 days of therapy. All systemic anti-infectives studied were more active than was no treatment. Daptomycin- or vancomycin-loaded PMMA did not, however, exhibit microbiological efficacy alone or adjunctively, as assessed 21 days after implantation. CONCLUSIONS: Daptomycin is released from PMMA in vivo at a rate similar to that of vancomycin. Systemic daptomycin is as active as vancomycin in a rat model of chronic MRSA experimental osteomyelitis.

Animals↗
PubMed2005

Total knee arthroplasty for salvage of failed internal fixation or nonunion of the distal femur.

Seventeen patients with a mean age of 66 years had total knee arthroplasty (TKA) performed to salvage failed internal fixation or nonunion of the distal femur. Two patients died at less than 2 years, both of whom were unrevised. The remaining 15 were followed for a mean of 5 years. Three arthroplasties failed, 1 by infection and 2 by mechanical failure. The 5-year survivorship free of revision for aseptic failure was 91% (72%-100%). There were 5 intraoperative complications (29%) and 5 postoperative complications (29%). The mean Knee Society pain score improved from 2 (range, 0-10) to 89 (range, 63-97), and the mean functional score improved from 2 (range, 0-25) to 45 (range, 10-90). TKA provided reliable pain relief and functional improvement for the great majority of patients. Functional scores and prosthesis survivorship, however, were inferior to those reported for primary TKA. The surgeries were difficult, and intraoperative and postoperative complications were common.

Adult↗
PubMed2005

Functional results after revision of well-fixed components for stiffness after primary total knee arthroplasty.

Between 1990 and 2001, 16 well-fixed, aseptic, primary total knee arthroplasties were revised in 15 patients for a diagnosis of stiffness. Patients were followed for a mean of 42 months (range, 2-6 years). Of 15 patients, 10 (66%) were satisfied with the results of the procedure. The mean Knee Society pain score improved from 28 to 65 points, and the mean functional score improved from 45 to 58 points. The mean arc of motion improved from 40 degrees preoperatively to 73 degrees postoperatively. Recurrent stiffness required additional intervention in 4 knees (3 patients, 25%). The results of revision of a well-fixed, stiff, primary total knee arthroplasty were mixed in our hands and provided only modest improvements in pain, function, and arc of motion. Key words: knee, arthroplasty, stiffness, revision, arthrofibrosis.

Aged↗
PubMed2005

Flexion instability without dislocation after posterior stabilized total knees.

UNLABELLED: Flexion instability after cruciate-retaining total knee arthroplasty has been well documented. We identified an analogous patient group with symptomatic flexion instability without dislocation after primary posterior stabilized total knee arthroplasty. We sought to determine the typical symptoms and exam findings that lead to the diagnosis, to assess the reliability of revision total knee arthroplasty as a treatment, and to assess the technical difficulties encountered during revision total knee arthroplasty. Between 1995 and 2001, 10 patients had revision of a well-fixed posterior stabilized total knee arthroplasty for isolated symptomatic flexion instability. The typical constellation of symptoms and physical findings included a sense of instability without giving way, recurrent knee effusions, multiple areas of soft tissue tenderness about the knee, and substantial anterior tibial translation at 90 degrees of flexion. The revision operation focused on balancing the flexion and extension gaps while taking care to fill the enlarged flexion gap. Revision total knee arthroplasty was reliable in alleviating pain (mean Knee Society Pain scores improved from 68 points preoperatively to 89 points postoperatively), improving stability (nine of 10 patients had < 5 mm anterior tibial translation postoperatively) and improving patient satisfaction (nine of 10 patients were satisfied). We had no particular technical difficulties with the revision total knee arthroplasty procedures and had reliably achieved well-balanced flexion and extension gaps. LEVEL OF EVIDENCE: Therapeutic study, Level IV-1 (case series). See the Guidelines for Authors for a complete description of levels of evidence.

Aged↗
PubMed2005

Surgical treatment of the middle-aged patient with arthritic knees.

Arthritic knee disease is increasingly more common in the active aging population. The pathology seen in this patient group can run a spectrum of localized degenerative change through tricompartmental arthritis. Nonsurgical options to treat early symptoms are well known and often are effective. When nonsurgical management has failed, surgical intervention often is warranted. Arthroscopic debridement is considered in select patients with mechanical symptoms. Osteotomy continues to have a role in the treatment of young, active patients and may be particularly appropriate in combination with articular cartilage procedures. Unicompartmental and total knee arthroplasty are reliable treatments for patients with advanced stages of degenerative arthritis.

Anterior Cruciate Ligament↗
PubMed2004

Release of daptomycin from polymethylmethacrylate beads in a continuous flow chamber.

Because daptomycin is active against Gram-positive cocci, it may be useful in the treatment and prevention of bone and joint infections when incorporated into polymethylmethacrylate (PMMA). The release kinetics of daptomycin from PMMA were studied in a continuous flow chamber designed to simulate in vivo conditions. Three-millimeter beads containing 2.5%, 7.5%, and 15.0% daptomycin (weight daptomycin per weight PMMA) were individually placed in a chamber with 1 mL Krebs Ringer buffer flowing at 1 mL/hour. The majority of daptomycin was released in the first 24 hours. The mean peak concentrations were 13.4, 62.3, and 146.7 microg/mL; the mean AUC0-infinity were 30, 272, and 1204 h x microg/mL; and the mean percentages of daptomycin released were 6%, 18%, and 42% for the beads containing 2.5%, 7.5%, and 15.0% daptomycin, respectively. Daptomycin is released from PMMA in a continuous flow chamber at a rate similar to that previously determined by our laboratory for vancomycin.

Anti-Bacterial Agents↗
PubMed2004

Management of pathologic fractures of the proximal femur: state of the art.

Metastases to bone are the most common cause of a destructive lesion of the skeleton in an adult. The proximal femur is the most commonly affected bone with metastatic disease in the appendicular skeleton. A systematic approach to patient management is critical, so as to avoid complications that will delay systemic therapy. The orthopedic traumatologist is often the first physician to see the patient with a pathologic fracture. As a result, the surgeon must be aware of the indications for resection versus internal fixation, as well as options for reconstruction. Polymethyl methacrylate and curettage can be useful in the appropriately selected patient. Postoperative external beam irradiation can significantly reduce disease progression and subsequent loss of fixation. A multidisciplinary approach to this patient group will help optimize prognosis as well as function. This article reviews the evaluation, management, and complications of treatment of pathologic fractures of the proximal femur, with an emphasis on metastatic disease and multiple myeloma.

Femoral Fractures↗
PubMed2004

Complications and results of arthroplasty for salvage of failed treatment of malignant pathologic fractures of the hip.

The purpose of this study was to evaluate the results and complications of hip arthroplasty done for salvage of failed treatment of pathologic proximal femoral fractures secondary to malignancy. Between 1980 and 2000, 42 patients with a mean age of 63 years were treated with hip arthroplasty to salvage failed treatment of a pathologic proximal femoral fracture. Total hip arthroplasty was done in 16 patients (3 uncemented, 2 hybrid, 11 cemented), and bipolar hemiarthroplasty in 26 (2 uncemented, 24 cemented). A modular, proximal femoral replacement construct was used in 15 patients. Patients were followed a mean of 5.8 years (range, 15 days-20 years). Four hips required reoperation, all for deep infection. Harris Hip score improved from an average of 42 points (range, 17-76 points) preoperatively to an average of 83 points (range, 52-100 points) postoperatively. Most recent radiographs showed femoral component loosening in only one patient. Implant survivorship free of revision for any reason at 5 years was 90% (range, 65-96%) and free of revision for aseptic failure or radiographic failure was 97% (range, 64-99%). Hip arthroplasty is an effective treatment for salvage of failed treatment of pathologic proximal femoral fractures. Modular proximal femoral replacements were often required. The most concerning complication was deep prosthetic infection, which occurred in nearly 10% of this patient population, and in 21% of patients with prior irradiation.

Adult↗
PubMed2004

Wound complications after open Achilles tendon repair: an analysis of risk factors.

Operative treatment of Achilles tendon ruptures has the risk of wound complications. The purpose of this study is to determine the risk ratio for specific risk factors associated with wound related complications in patients with operatively treated Achilles tendon ruptures. Between 1978 and 2001, 167 open Achilles tendon repairs were done at our institution. Clinical data were retrospectively reviewed. Tobacco use, diabetes, age, gender, timing of surgery, body mass index and steroid use were evaluated as potential risk factors for wound healing complications. One patient was lost to follow-up and two patients had nonsimultaneous ruptures and only the first repair was included; the remaining patients were followed up until complete wound healing. There were 17 wound complications in 164 patients (10.4%). Significant risk factors for development of wound complications included tobacco use (p < 0.0001), steroid use (p = 0.0005), and female sex (p = 0.0400). For those patients who had one or more of the following risk factors: diabetes, tobacco use, or steroid use; eight of 19 (42.1%) had a complication, compared with nine of 145 (6.2%) for those without risk factors present (p < 0.0001). Surgeons doing open Achilles tendon repairs should be cognizant of the specific risk factors identifled in this study, because they might impact decision making with regard to operative versus nonoperative treatment.

Achilles Tendon↗
PubMed2004

Systemic safety of high-dose antibiotic-loaded cement spacers after resection of an infected total knee arthroplasty.

The purpose of this study was to assess the systemic safety and potential adverse effects of using a high-dose antibiotic-impregnated cement spacer after resection arthroplasty of an infected total knee replacement. Between October 2000 and December 2002, 36 knees (34 patients) had a resection arthroplasty of an infected total knee prosthesis with placement of a high-dose antibiotic impregnated cement spacer. There were 24 men and 10 women with a mean age of 66.5 years (range, 48-84 years). All spacers placed contained an average of 3.4 batches of cement with an average total dose of 10.5 g of vancomycin (range, 3-16 g) and 12.5 g of gentamicin (range, 3.6-19.2 g). All patients were followed up post-operatively until reimplantation for evidence of renal failure. The preoperative creatinine ranged from 0.7 to 1.8 mg/dL. All patients were concomitantly treated with 6 weeks of intravenous organism-specific antibiotics. One patient with normal preoperative renal function (Cr 0.7 mg/dL) had a perioperative 1-day transient rise in serum creatinine (1.7 mg/dL) postoperatively that subsequently normalized. No patients showed any clinical evidence of acute renal insufficiency, failure, or other systemic side effects of the antibiotics. Treatment of patients with an infected total knee arthroplasty with high-dose vancomycin and gentamicin antibiotic spacers seems to be clinically safe.

Aged↗
PubMed2004

Operative treatment of femoral neck fractures in patients between the ages of fifteen and fifty years.

BACKGROUND: There is a paucity of data on the treatment of femoral neck fractures in young patients. The purpose of the present study was to review the results and complications associated with the treatment of femoral neck fractures with internal fixation in a large consecutive series of young patients. METHODS: Between 1975 and 2000, eighty-three femoral neck fractures in eighty-two consecutive patients who were between fifteen and fifty years old were treated with internal fixation at our institution. Two patients died, and eight were lost to follow-up. Seventy-three fractures were followed until union, until conversion to hip arthroplasty, or for a minimum of two years; the mean duration of follow-up was 6.6 years. Fifty-one of the seventy-three fractures were displaced, and twenty-two were nondisplaced. The results and complications of treatment were retrospectively reviewed, and the effects of fracture displacement, reduction quality, and capsular decompression on outcome were evaluated. Function was assessed by evaluating pain, walking capacity, and the need for gait aids. The mean duration of follow-up for the fifty-seven patients (fifty-eight fractures) who had not undergone early conversion to arthroplasty was 8.1 years. RESULTS: Fifty-three (73%) of the seventy-three fractures healed after one operation and were associated with no evidence of osteonecrosis of the femoral head. Osteonecrosis developed in association with seventeen fractures (23%), and a nonunion developed in association with six (8%). Four of the six nonunions later healed after a secondary procedure. At the time of the final follow-up, thirteen patients had had a conversion to a total hip arthroplasty because of osteonecrosis (eleven), nonunion (one), or both (one). Five (9.8%) of the fifty-one displaced fractures were associated with the development of nonunion, and fourteen (27%) were associated with the development of osteonecrosis. Three (14%) of the twenty-two nondisplaced fractures were associated with the development of osteonecrosis, and one (4.5%) was associated with the development of nonunion. Eleven (24%) of the forty-six displaced fractures with a good to excellent reduction were associated with the development of osteonecrosis, and two (4%) were associated with the development of nonunion. Four of the five displaced fractures with a fair or poor reduction were associated with the development of osteonecrosis, nonunion, or both. CONCLUSIONS: The ten-year survival rate of the native femoral head free of conversion to total hip arthroplasty was 85%. Osteonecrosis was the main reason for conversion to total hip arthroplasty, but not all patients with osteonecrosis required further surgery. The results of treatment were influenced by fracture displacement and the quality of reduction.

Adolescent↗