PubMed Health⌕ Search

Biomedical subjects

Pierre Hoffmeyer

Publications and source records attributed to Pierre Hoffmeyer.

31 records · Page 2Linked to original sources
PubMed2004

Computer-assisted cup placement techniques in total hip arthroplasty improve accuracy of placement.

Malposition of the acetabular component during hip arthroplasty increases the occurrence of impingement, reduces range of motion, and increases the risk of dislocation and long-term wear. To prevent malpositioned hip implants, an increasing number of computer-assisted orthopaedic systems have been described, but their accuracy is not well established. The purpose of this study was to determine the reproducibility and accuracy of conventional versus computer-assisted techniques for positioning the acetabular component in total hip arthroplasty. Using a lateral approach, 150 cups were placed by 10 surgeons in 10 identical plastic pelvis models (freehand, with a mechanical guide, using computer assistance). Conditions for cup implantations were made to mimic the operating room situation. Preoperative planning was done from a computed tomography scan. The accuracy of cup abduction and anteversion was assessed with an electromagnetic system. Freehand placement revealed a mean accuracy of cup anteversion and abduction of 10 degrees and 3.5 degrees, respectively (maximum error, 35 degrees). With the cup positioner, these angles measured 8 degrees and 4 degrees (maximum error, 29.8 degrees), respectively, and using computer assistance, 1.5 degrees and 2.5 degrees degrees (maximum error, 8 degrees), respectively. Computer-assisted cup placement was an accurate and reproducible technique for total hip arthroplasty. It was more accurate than traditional methods of cup positioning.

Arthroplasty, Replacement, Knee↗
PubMed2004

Relative rates and features of musculoskeletal complications in adult sicklers.

The purpose of this study was to prospectively look for the relative rates and features of musculoskeletal complications in a sample of adult homozygous SS sicklers in Yaoundé. During a 3-year period, known homozygous SS sicklers aged sixteen years or more, with suspicion or evidence of locomotor system disease, including leg ulcer, were consecutively investigated through complete medical history, clinical examination, full blood count, C-reactive protein, standard radiographs of the area of complaint, and, when necessary, CT scan and pus analysis. Those patients with no definite diagnosis were excluded. The study group comprised 84 patients aged 16 to 51 years (mean age: 22 years), with a male/female ratio of 0.75. Four of them (4.5%) were older than 40 years. Thirty five (41.6%) presented a total of 50 lesions of aseptic osteonecrosis, which were located in the hips in 25 cases (50%), in the lumbar spine in 20 cases (40%), in the humeral head in four cases (10%) and in the talar body in one case. The hip necrosis was grade I in 6 cases, grade II in four, grade III in 11 and terminal in four. Multiple sites of necrosis were observed in six patients. Nineteen (22.6%) of the sicklers came on with 36 malleolar ulcers, more frequently in males (sex ratio: 5/1) and 28 (78%) located on the medial side. Fifteen sites of osteomyelitis were noted in 14 patients (17.8%) and septic arthritis in six (7%). Less frequent complications were impingement syndrome, gout osteoarthropathy, stress fracture, subtalar fusion, knee osteoarthritis, tendonitis of the anterior tibialis, and recurrent dislocation of the patella. All patients were managed conventionally, except for advanced aseptic necrosis in which the indication for arthroplasty was delayed till the terminal stage. As suggested by another recent report from Senegal, efforts should be made to improve the life expectancy of sicklers in Sub-Saharan African countries, by acting on education, social and medical care. Orthopaedic surgery should focus on reducing the failure rate of joint replacement in terminal stages of osteonecrosis and designing core decompression trials in early stages.

Adolescent↗
PubMed2003

Trends in the treatment of orthopaedic prosthetic infections.

The most commonly used therapy for prosthetic joint infection is a two-stage prosthetic exchange separated by 6 weeks of intravenous antibiotic therapy. This often results in long periods of hospitalization, morbidity, severe functional impairment and sometimes increased mortality. Therefore novel and challenging therapeutic approaches have been attempted, particularly in hip prosthetic infection. This includes, whenever possible, according to the type of microorganism, antibacterial susceptibility and clinical presentation (including age and comorbidities): (i) less aggressive surgical techniques (debridement and prosthesis retention, or re-implantation with a single-stage exchange arthroplasty); and (ii) antibiotic combinations active against biofilm-associated bacteria, including rifampicin (particularly with quinolones) with excellent bio-availability which allow prolonged and efficient oral therapy.

Anti-Bacterial Agents↗
PubMed2003

Effect of vancomycin therapy for osteomyelitis on colonization by methicillin-resistant Staphylococcus aureus: lack of emergence of glycopeptide resistance.

BACKGROUND: In treating orthopedic infections, the long-term impact of vancomycin therapy on colonization by methicillin-resistant Staphylococcus aureus (MRSA) and the emergence of vancomycin-intermediate S. aureus is unknown. DESIGN: Prospective surveillance of the effect of long-term vancomycin therapy on colonization by MRSA and the emergence of vancomycin-intermediate S. aureus. METHODS: Thirty-four patients with MRSA osteomyelitis that was microbiologically documented were longitudinally observed for the emergence of vancomycin-intermediate S. aureus at 3 body sites (wound, anterior nares, and groin) during the initial period of vancomycin therapy and at the 2-month follow-up. Twenty patients received the standard dose (20 mg/kg/d) for 34 +/- 6 days and 14 patients received a high dose (40 mg/kg/d) of vancomycin for 37 +/- 9 days. RESULTS: During vancomycin treatment, global MRSA carriage (all body sites) fell from 100% to 25% in the group of patients receiving the standard dose of vancomycin, and from 100% to 40% in the group receiving the high dose. During the 2-month follow-up period after vancomycin therapy, global MRSA carriage increased from 25% to 55% in the group receiving the standard dose and decreased from 43% to 36% in the group receiving the high dose. CONCLUSION: Therapy with a high dose of vancomycin contributes to the sustained eradication of MRSA carriage without promoting the emergence of glycopeptide resistance.

Adult↗
PubMed2003

Isobaric versus hypobaric spinal bupivacaine for total hip arthroplasty in the lateral position.

UNLABELLED: Total hip arthroplasty (THA) is frequently performed under spinal anesthesia using either isobaric or hypobaric anesthetic solution. However, these two solutions have never been compared under similar surgical conditions. In the present study, we compared the anesthetic and hemodynamic effects of isobaric and hypobaric bupivacaine in 40 ASA physical status I-II patients undergoing THA in the lateral decubitus position under spinal anesthesia. With operative side up, patients randomly received, in a double-blinded manner, a spinal injection of 3.5 mL (17.5 mg) of plain bupivacaine mixed with either 1.5 mL of normal saline (isobaric group) or 1.5 mL of distilled water (hypobaric group). Sensory level and degree of motor block were evaluated on the nondependent and dependent sides until regression to L2 and total motor recovery. Hemodynamic changes during the first 45 min after spinal injection, and the time between spinal administration and first analgesic for a pain score >3 (on a 0-10 scale) were noted. Demographic characteristics of both groups were comparable. Upper sensory level and maximal degree of motor block were comparable between the operative and nonoperative sides in each group and between corresponding sides in both groups. Compared with the isobaric group, in the hypobaric group there was a prolonged time to sensory regression to L2 on the operative side (287 +/- 51 versus 242 +/- 36 min, P < 0.004) and a prolonged time to first analgesic (290 +/- 46 versus 237 +/- 39 min, P < 0.001). No difference in quality of motor block was noted at the end of surgery. Hemodynamic changes were comparable. We conclude that for THA in the lateral position, spinal hypobaric bupivacaine seems to be superior to isobaric in that it prolongs the sensory block on the operative side and delays the use of analgesics after surgery without further compromising hemodynamic stability. IMPLICATIONS: For total hip arthroplasty in the lateral position, spinal hypobaric bupivacaine compared with isobaric prolonged sensory block at the operative side and delayed the time to first analgesic.

Anesthesia, Spinal↗
PubMed2002

Hip fracture surgery: is the pre-operative American Society of Anesthesiologists (ASA) score a predictor of functional outcome?

BACKGROUND AND AIMS: Many studies have identified specific demographic, social, health or life-style pre-operative indicators of long-term outcome among older hip fracture patients who underwent surgical treatment. The purpose of this study was to determine the predictive value of peri- and intra-operative factors, and more specifically of the pre-operative American Society of Anesthesiologists (ASA) score on functional outcome in these patients. METHODS: A questionnaire designed to assess pre-fracture functional and health status was administered to surgically treated hip fracture patients. Post-fracture functional and health status was further ascertained by in-home interview one year after the operation. Among 140 consecutive eligible patients older than 65 years, 10 either refused subsequent interviews or could not be contacted; an additional 16 patients died during the year of follow-up, leaving 114 patients available for this study. RESULTS: The average age of the patients was 82.4 years. Almost two-thirds of them suffered from severe systemic disease, whether or not incapacitating (ASA grades III-IV). Subjects classified in these categories presented more frequently with cardiovascular disorders, were more frequently disoriented, and already had some pre-fracture difficulty with ambulation. The mortality at one year was almost nine times higher in severely impaired patients (grades III-IV) than in healthy or mildly affected patients (grades I-II). Functional outcome and/or ambulatory ability assessed at one year did not reveal any statistically significant difference between the ASA I-II and III-IV groups. The most pronounced difference was noticed for the functional independence measured by the ADL score (p = 0.236). Better prognoses were consistently recorded for patients with an intracapsular fracture, for those who were operated within 24 hours, for those treated with a prosthesis as opposed to internal fixation, and for those whose operating time was less than 1 1/2 hours. CONCLUSIONS: Although the ASA classification is a good predictor of long-term mortality, the findings of the present investigation do not conclusively associate ASA score with post-operative restoration of mobility and functional independence.

Activities of Daily Living↗
PubMed2002

Pertrochanteric fractures: is there an advantage to an intramedullary nail?: a randomized, prospective study of 206 patients comparing the dynamic hip screw and proximal femoral nail.

OBJECTIVES: To compare the results between a sliding compression hip screw and an intramedullary nail in the treatment of pertrochanteric fractures. DESIGN: Prospective computer-generated randomization of 206 patients into two study groups: those treated by sliding compression hip screw (Group 1; n = 106) and those treated by intramedullary nailing (Group 2; n = 100). SETTING: University Level I trauma center. PATIENTS: All patients over the age of fifty-five years presenting with fractures of the trochanteric region caused by a low-energy injury, classified as AO/OTA Type 31-A1 and A2. INTERVENTION: Treatment with a sliding compression hip screw (Dynamic Hip Screw; Synthes-Stratec, Oberdorf, Switzerland) or an intramedullary nail (Proximal Femoral Nail; Synthes-Stratec, Oberdorf, Switzerland). MAIN OUTCOME MEASUREMENTS: Intraoperative: operative and fluoroscopy times, the difficulty of the operation, intraoperative complications, and blood loss. Radiologic: fracture healing and failure of fixation. Clinical: pain, social functioning score, and mobility score. RESULTS: The minimum follow-up was one year. We did not find any statistically significant difference, intraoperatively, radiologically, or clinically, between the two groups of patients. CONCLUSIONS: There is no advantage to an intramedullary nail versus a sliding compression hip screw for low-energy pertrochanteric fractures AO/OTA 31-A1 and A2, specifically with its increased cost and lack of evidence to show decreased complications or improved patient outcome.

Aged↗
PubMed2002

Limited open repair of Achilles tendon ruptures: a technique with a new instrument and findings of a prospective multicenter study.

BACKGROUND: Controversy persists regarding the ideal surgical technique for repair of a ruptured Achilles tendon. We propose a limited open procedure with use of an instrument that provides the advantage of an open repair but avoids the soft-tissue problems with which open repair has been associated. METHODS: We first performed a cadaver study in order to develop an instrument and a technique for a limited open repair and then, using this procedure in conjunction with an early functional rehabilitation protocol, we began a prospective multicenter study. We are reporting on the first eighty-seven patients consecutively treated with the new instrument and followed for an average of twenty-six months (range, eighteen to forty-two months). All patients were assessed clinically and with an enhanced American Orthopaedic Foot and Ankle Society (AOFAS) rating score. In addition, all fifty patients who had been followed for at least twenty-four months were further evaluated with isokinetic dynamometry. RESULTS: Four patients were lost to follow-up and one patient died, which left eighty-two patients for evaluation. There were no problems with wound-healing, and there were no infections. No patient noted a sensory disturbance in the sural nerve distribution. All patients returned to their previous professional or sporting activities. The mean AOFAS score was 96 points (range, 85 to 100 points). Isokinetic dynamometry showed no significant difference in strength between the injured and uninjured limbs of the fifty patients who were tested. Complications occurred in three patients. Two of them were noncompliant and removed the orthosis, so that the repair was disrupted by a new injury within the first three weeks postoperatively. One patient fell twelve weeks after the surgery and sustained a rerupture. All three new injuries were repaired with an open surgical procedure. CONCLUSIONS: This new procedure allows the surgeon to precisely visualize and control the tendon ends while avoiding excessive dissection and disturbance of local vascularity and minimizing nerve and wound-healing problems. Such a technique, along with an early functional rehabilitation program, allowed us to achieve a high rate of successful results with minimal morbidity.

Achilles Tendon↗
PubMed2002

Treatment of reverse oblique and transverse intertrochanteric fractures with use of an intramedullary nail or a 95 degrees screw-plate: a prospective, randomized study.

BACKGROUND: Intertrochanteric fractures are composed of different anatomic patterns that vary in their degree of stability following open reduction and internal fixation. A particularly unstable group is classified as AO/OTA 31-A3, with the fracture pattern described as reverse oblique or transverse. The purpose of this study was to compare the results of intramedullary fixation with those of plate fixation for these intertrochanteric fractures in elderly patients. METHODS: Thirty-nine elderly patients with AO/OTA 31-A3 intertrochanteric fractures of the femur were randomized into two treatment groups and were followed for a minimum of one year. The nineteen patients in Group I were treated with a 95 fixed-angle screw-plate (Dynamic Condylar Screw), and the twenty patients in Group II were treated with an intramedullary nail (Proximal Femoral Nail). The treatment groups were comparable with regard to all demographic and injury variables. RESULTS: Patients treated with an intramedullary nail had shorter operative times, fewer blood transfusions, and shorter hospital stays compared with those treated with a 95 screw-plate. Implant failure and/or nonunion was noted in seven of the nineteen patients who had been treated with the 95 screw-plate. Only one of the twenty fractures that had been treated with an intramedullary nail did not heal. CONCLUSION: The results of our study support the use of an intramedullary nail rather than a 95 screw-plate for the fixation of reverse oblique and transverse intertrochanteric fractures in elderly patients.

Aged↗
PubMed2002

Anterior shoulder instability: histomorphometric study of the subscapularis and deltoid muscles.

Recurrent traumatic anterior shoulder dislocation results in soft tissues lesions around the glenohumeral joint. The subscapularis muscle is a major active stabilizer of the shoulder and the hypothesis of the current study is that one would expect pathologic changes within its substance secondary to the trauma. A histomorphometric study of the subscapularis muscle was done of 52 patients operated on for recurrent traumatic anterior shoulder dislocation. At the time of surgery biopsy specimens were taken of the subscapularis muscle and the ipsilateral deltoid muscle as a comparison and to see if any changes were present. The results revealed interstitial fibrosis within the subscapularis muscle compatible with muscle scarring, and modifications in the ratio of fiber types as usually is seen with disuse atrophy. Both of these findings may alter strength and stability and therefore the function of the glenohumeral joint. The histologic findings were not compatible with a denervation pattern. After traumatic anterior shoulder dislocation rehabilitation of the subscapularis muscle is recommended.

Adolescent↗
PubMedDate not supplied

Arterial supply of the glenoid: an anatomic study.

Surgery is performed on the glenoid for a variety of pathologic conditions, and an adequate blood supply is required to achieve good healing of soft tissue and bone. The objective of this investigation was to study the arterial supply of the glenoid in 24 fresh human cadaveric specimens. The vascular supply originates from branches of the anterior and posterior circumflex arteries and the suprascapular artery and branches directly from the infraspinatus and teres minor muscles. The antero-superior portion of the glenoid is poorly vascularized, with a specific area that is completely devoid of blood supply. In addition, circumferentially around the glenoid rim, there is an area of approximately 5 mm from the edge that is completely devoid of vascularity. Adequate bone and soft-tissue healing in the glenoid, particularly in its anterosuperior portion, after fracture repair, osteotomy, total shoulder arthroplasty, and capsular procedures may be compromised by the demonstrated hypovascularity.

Aged↗
PubMedDate not supplied

Fixation of fractures of the proximal humerus with the PlantTan Humerus Fixator Plate: early experience with a new implant.

The majority of fractures of the proximal humerus can be managed nonoperatively. However, displaced fractures generally require operative repair, and in the young patient with good bone quality, the results are usually satisfactory. In contrast, the osteoporosis found in the elderly patient makes internal fixation problematic and frequently contributes to failure of fixation and poor results. We report our early experience with a new plate that locks two humeral head cancellous screws to the plate. In 3 of 7 patients, all under 65 years of age, the results were good. However, in the remaining 4 patients, all over the age of 75 years, there was a 100% failure rate, with screw penetration of the head in 3 patients and secondary displacement of the fracture at 7 days postoperatively in another. We conclude that this implant is unsatisfactory for patients with osteopenic bone in the humeral head.

Adult↗