Biomedical subjects

Michael E Hantes

Publications and source records attributed to Michael E Hantes.

13 recordsLinked to original sources

PubMed2007

Patellar tendon length after anterior cruciate ligament reconstruction: a comparative magnetic resonance imaging study between patellar and hamstring tendon autografts.

Patellar tendon shortening after anterior cruciate ligament reconstruction may be associated with anterior knee pain or patellofemoral arthritis. The present study was designed to compare postoperative changes in patellar tendon length after anterior cruciate ligament reconstruction between patellar tendon and hamstring tendon autograft. Magnetic resonance images of both knees (operated and healthy) and functional outcome were documented at least 1 year postoperatively in 16 patellar tendon harvested patients and in 32 hamstrings harvested patients. Patellar tendon length, patella length and Insall-Salvati ratio were measured. The operated knee values were compared to the respective values of the non-operated control knees. A significant 4.2 mm or 9.7% patellar tendon shortening in patellar tendon group and a non-significant 1.14 mm or 2.6% shortening in hamstrings group was detected. No significant difference was detected in terms of major shortening-patella baja-(6% for the patellar tendon group vs. 0% for the hamstring group). There was no significant difference in anterior knee problems between the two groups as evidenced by the Shelbourne score (94 for the patellar tendon group vs. 98 for the hamstring group). Harvesting of the patellar tendon for anterior cruciate ligament reconstruction resulted in a significant shortening of the remaining tendon. In contrast harvesting of the hamstring tendons did not affect significantly the patellar tendon length. However, the incidence of patella baja and overall functional outcome was not significantly different between the two groups.

Adolescent↗

PubMed2006

Arthroscopic meniscal repair: a comparative study between three different surgical techniques.

The purpose of this prospective study was to evaluate and compare the results of arthroscopic meniscal repair using three different techniques. Between January 2002 and March 2004, 57 patients who met the inclusion criteria underwent an arthroscopic meniscal repair. The outside-in technique was used in 17 patients (group A), the inside-out in 20 patients (group B), while the rest of the 20 patients (group C) were managed by the all-inside technique using the Mitek RapidLoc soft tissue anchor (Mitek Surgical Products, Westwood, MA, USA). Anterior cruciate ligament (ACL) reconstruction was performed in 29 patients (51%). The criteria for clinical success included absence of joint line tenderness, locking, swelling, and a negative McMurray test. The minimum follow-up was one year for all groups. The mean follow-up was 23 months for group A, 22 months for group B, and 22 months for group C. All meniscal repairs were considered healed according to our criteria in group A, while 19 out of 20 repairs (95%) healed in group B. Finally 7 of 20 repairs (35%) were considered failures in group C and this difference was statistically significant in comparison with other groups. The time required for meniscal repair averaged 38.5 min for group A, 18.1 min for group B, and 13.6 min for group C. Operation time for meniscal repair in group A was statistically longer in comparison with other groups. There were no significant differences among the three groups concerning complications. According to our results, arhtroscopic meniscal repair with the inside-out technique seems to be superior in comparison with the other methods because it offers a high rate of meniscus healing without prolonged operation time.

Adult↗

PubMed2006

Low-intensity pulsed ultrasound for bone healing: an overview.

Low-intensity ultrasound is a biophysical form of intervention in the fracture-repair process, which through several mechanisms accelerates healing of fresh fractures and enhances callus formation in delayed unions and nonunions. The goal of this review is to present the current knowledge obtained from basic science and animal studies, as well as existing evidence from clinical trials and case series with the different applications of ultrasound in the management of fractures, delayed unions, nonunions and distraction osteogenesis. Low-intensity pulsed ultrasound is currently applied transcutaneously, although recent experimental studies have proven the efficacy of a trans-osseous application for both enhancement and monitoring of the bone healing process with modern smart implant technologies.

Animals↗

PubMed2006

Results of all-inside meniscal repair with the FasT-Fix meniscal repair system.

PURPOSE: The goal of this prospective study was to evaluate the results of arthroscopic meniscal repair using the FasT-Fix repair system. TYPE OF STUDY: Prospective case series. METHODS: Sixty-one meniscal repairs with the FasT-Fix meniscal repair system in 58 patients with a mean age of 32.6 years were performed between 2001 and 2002. Concurrent anterior cruciate ligament reconstruction was performed in 36 patients (62%). All tears were longitudinal and located in the red/red or red/white zone. Criteria for clinical success included absence of joint-line tenderness, locking, swelling, and a negative McMurray test. Clinical evaluation also included the Tegner and Lysholm knee scores, and KT-1000 arthrometry. In addition, all patients were evaluated preoperatively with magnetic resonance imaging. RESULTS: The average follow-up was 18 months (range, 14 to 28 months). Six of 61 repaired menisci (9.8%) were considered failures according to our criteria. Therefore, the success rate was 90.2%. Time required for meniscal repair averaged 11 minutes. Postoperatively, the majority of the patients had no restrictions in sports activities. The mean Lysholm significantly improved from 43.6 preoperatively to 87.5 postoperatively (P < .001). Fifty-one patients (88%) had an excellent or good result according to the Lysholm knee score. Four patients had a restriction of knee joint motion postoperatively, and an arthroscopic arthrolysis was performed in 1 of them. Analysis showed that age, length of tear, simultaneous anterior cruciate ligament reconstruction, chronicity of injury, and location of tear did not affect the clinical outcome. CONCLUSIONS: Our results show that arthroscopic meniscal repair with the FasT-Fix repair system provided a high rate of meniscus healing and appeared to be safe and effective in this group of patients. LEVEL OF EVIDENCE: Level IV, therapeutic study, case series (no control group).

Adult↗

PubMed2005

Anterior cruciate ligament reconstruction using the Bio-TransFix femoral fixation device and anteromedial portal technique.

The cross-pin femoral fixation technique for soft tissue grafts is a popular option in anterior cruciate ligament (ACL) reconstruction. One of these devices is the Bio-TransFix (Arthrex Inc., Naples, FL, USA) which provides high fixation strength. According to the manufacturer, the femoral tunnel is created by placing the femoral aiming device through the tibial tunnel (transtibial technique). However, using this technique it is very difficult or even impossible to place the graft at the anatomical ACL attachment site at the "10 o'clock" position. In this report, we describe the use of the Bio-TransFix device with an anteromedial portal technique. Using this technique, the surgeon has more freedom to place the graft in an anatomical position, while combining the advantages of the excellent biomechanical properties of this device.

Absorbable Implants↗

PubMed2005

Changes of meniscal interhorn distances: an in vivo magnetic resonance imaging study.

The aim of this study was to evaluate the changes of the internal (IID) and external meniscal interhorn distance (EID) of the medial and the lateral meniscus under loading. Sagittal magnetic resonance images of 15 knees were studied. The medial and lateral meniscus were examined with the knee at 0 degrees and 30 degrees of flexion, under no load, with load equal to 50% of body weight and with load equal to 100% of body weight. Under no load, the mean IID was 19.9 mm for the medial meniscus and 12.3 mm for the lateral meniscus and the mean EID was 44.6 mm for the medial meniscus and 34.4 mm for the lateral meniscus. Under load equal to 50% and 100% of patient's body weight, there was a significant increase in both distances (p<0.05). Under constant loading, flexion of the knee from 0 degrees to 30 degrees , decreased the EID of both menisci. In conclusion, loading increases both IID and EID. Knee position affects only the EID. The quality of magnetic resonance images may affect the reliability of such measurements.

Adult↗

PubMed2004

Arthroscopic meniscal repair with an absorbable screw: results and surgical technique.

The results of a new method for arthroscopic all-inside meniscus repair using a biodegradable cannulated screw (Clearfix meniscal screw) were assessed in a medium-term follow-up prospective study. The Clearfix meniscal screw system consists of delivery cannulae, screw driver, and screw implants. After tear debridement, a screw is located on the driver and passed through the cannula to the insertion site, holding the two sides of the tear together under linear compression. Forty-eight patients (48 repairs) with a mean age of 32.7 years were included in the study. Ligament stabilizing procedures were done in 39 patients (81%) who had anterior cruciate ligament deficient knees. Only longitudinal lesions in the red/red or red/white zone were repaired. Follow-up averaged 19 months, with a range from 12 to 48 months. Patients were evaluated using clinical examination, the "Orthopaedische Arbeitsgemeinschaft Knie (OAK)" knee evaluation scheme and magnetic resonance imaging (MRI). Criteria for clinical success included absence of joint-line tenderness, absence of swelling and a negative McMurray test. Postoperatively, there were no complications directly associated with the device. Twelve of 48 repaired menisci (25%) were considered failures according to the above-mentioned criteria. According to the OAK knee evaluation scheme, 38 patients (79%) had an excellent or good result. MRI, however, showed persisting grade III or IV lesions in 35 patients (73%). Analysis showed that age, length of tear, and simultaneous anterior cruciate ligament reconstruction did not affect the clinical outcome. In contrast, risk factors for failure of meniscus repair are chronicity of injury, location of tear more than 3 mm from the meniscosynovial junction and meniscus side (medial).

Absorbable Implants↗

PubMed2004

Localized pigmented villonodular synovitis in the anteromedial compartment of the knee associated with cartilage lesions of the medial femoral condyle: report of a case and review of the literature.

Localized pigmented villonodular synovitis (PVNS) of the knee is an uncommon entity, presenting with different clinical signs and symptoms. We report on a case of a 42-year-old woman who presented with a 3-year history of knee pain and mechanical problems such as locking. On examination she was found to have a palpable and painful mass over the anteromedial joint line. Magnetic resonance imaging (MRI) revealed a soft tissue mass in the anteromedial compartment of the knee joint. The lesion was completely resected arthroscopically, and histologic examination confirmed the diagnosis of localized PVNS. The patient was free of symptoms, and MRI examination showed no evidence of recurrence at 1-year follow-up.

Adult↗

PubMed2004

The effect of early motion on tibial tunnel widening after anterior cruciate ligament replacement using hamstring tendon grafts.

PURPOSE: The purpose of this study was to evaluate the hypothesis that early motion increases tibial tunnel enlargement in patients who underwent anterior cruciate ligament (ACL) replacement with hamstring autograft. TYPE OF STUDY: Cohort analytic study. METHODS: All patients in this study had received a doubled semitendinous and gracilis graft. Grafts were secured in place with an implant-free technique. Two groups of patients were evaluated. Group A consisted of 35 patients who underwent isolated ACL replacement and whose rehabilitation protocol included early motion. Group B consisted of 20 patients who underwent combined arthroscopic meniscal repair and ACL replacement. Partial weight bearing and restriction of range of motion for 6 weeks was recommended for these patients. The only 2 variables between the groups were the meniscal repair and the postoperative rehabilitation. Patients were evaluated clinically and radiographically at 3, 6, and 12 months postoperatively. After correction for radiographic magnification, the tibial tunnel was measured at distal (T1), middle (T2), and proximal (T3) locations on both anteroposterior and lateral views. RESULTS: At 1-year follow-up evaluations, tunnel enlargement was significantly higher in the group with early motion, in both the anteroposterior and lateral views, in all but one location (anteroposterior, T1). The enlargement was greater in the mid-portion (T2) of the tunnel in both groups. The mean percentage was 45.92% for group A and 23.34% for group B ( P <.05) in the anteroposterior view, and 48.14% for group A and 24.47% for group B ( P <.05) in the lateral view. No correlation was found between tunnel enlargement and clinical results or between tunnel enlargement and joint laxity measured by a KT-1000 arthrometer. CONCLUSIONS: Our study confirms that early motion increases the amount of tibial tunnel enlargement after anterior cruciate ligament replacement with hamstring autograft. This may have an impact on future rehabilitation protocols. LEVEL OF EVIDENCE: Level II.

Adult↗

PubMed2004

Arthroscopic autogenous osteochondral transplantation for treating knee cartilage defects: a 2- to 5-year follow-up study.

PURPOSE: The purpose of this retrospective analysis was to evaluate the medium-term results of arthroscopic treatment of chondral and osteochondral lesions of the knee with autogenous osteochondral transplantation (AOT). TYPE OF STUDY: Case series. METHODS: Thirty-three skeletally mature patients with symptomatic, full-thickness cartilage lesions of the femoral condyles, between 1 and 2.5 cm in diameter, were treated with arthroscopic AOT. Grafts were harvested from the superior and lateral intercondylar notch and press-fit into holes drilled into the defect. All patients were evaluated both preoperatively and postoperatively with the Lysholm knee score, International Knee Documentation Committee (IKDC) Standard Evaluation Form, and knee joint radiographs. RESULTS: Thirty patients of a mean age of 44.6 years were followed-up for a mean time of 45.1 months. Symptom duration ranged from 1 month to 15 years (median, 9.5 months). The mean Lysholm score significantly improved from 43.6 preoperatively to 87.5 postoperatively ( P <.001). Excellent or good outcome was accomplished in 25 of the patients (83%). Using the IKDC assessment, 26 of the patients (87%) reported their knee as being normal or nearly normal. Repeat arthroscopy with needle biopsy of the graft was performed in 9 patients. Seven of these had complete healing and 2 partial healing. The histologic examination revealed viable chondrocytes and normal hyaline cartilage in the completely healed cases. Congruency of the articular surface was restored in 11 of 12 patients (92%) who underwent magnetic resonance imaging examination. Abnormal marrow signal in the subchondral bone beneath the region of cartilage repair was present in 9 of 12 patients (75%), even 4 years after the procedure. CONCLUSIONS: Arthroscopic AOT is an effective and safe method of treating symptomatic full-thickness chondral defects of the femoral condyles in appropriately selected cases. However, further studies with long-term follow-up are needed to determine if the grafted area will maintain structural and functional integrity over time. LEVEL OF EVIDENCE: Level IV, therapeutic, case series (no, or historical, control group).

Adult↗

PubMed2004

Evaluation of meniscal repair with serial magnetic resonance imaging: a comparative study between conventional MRI and indirect MR arthrography.

OBJECTIVE: To prospectively investigate the healing process of meniscal repair with plain magnetic resonance imaging (MRI) and indirect MR arthrography and to compare the two methods. MATERIALS AND METHODS: Twenty patients with an arthroscopic meniscal repair without clinical symptoms underwent conventional and indirect MR arthrography of the affected knee, 3, 6 and 12 months after the index operation applying a T1-w Spin Echo sequence in three planes. The size of the tear gap was measured on transverse images. The signal-to-noise ratio and the configuration of the abnormal signal were evaluated in the coronal images. RESULTS: All patients demonstrated abnormal signal intensity at the side of the meniscal repair. The size of the gap at the previous tear side, reduced significantly by 45 and 40% on conventional MRI and indirect MR arthrography respectively, from 3 months to 1 year (P < 0.05). The signal-to-noise ratio of the intrameniscal abnormal signal reduced significantly and approximately 50% from 3 to 6 months, and from 6 to 12 months postoperatively, as demonstrated with indirect MR arthrography. However, as opposed to normal meniscus, the signal-to-noise ratio of the abnormal area remains 5.5 times higher 12 months postoperatively. In contrast, the reduction of signal-to-noise ratio of the abnormal area at conventional MRI was not significant even from 3 to 12 months. In 90% of the cases, the indirect MR arthrography showed the intrameniscal abnormal signal on plain MRI, to extend to the articular surface as opposed to 25% on plain MRI. CONCLUSION: With indirect MR arthrography, the natural process of meniscal healing can be evaluated. Significant reduction of the size of the tear gap and significant reduction of the signal-to-noise ratio of the abnormal signal as well as its configuration are the main parameters interpretating the normal healing process.

Adolescent↗

PubMed2004

Low-intensity transosseous ultrasound accelerates osteotomy healing in a sheep fracture model.

BACKGROUND: Low-intensity transcutaneous ultrasound can accelerate and augment the fracture-healing process. The aim of this study was to investigate the effect of transosseous application of low-intensity ultrasound on fracture-healing in an animal model. METHODS: A midshaft osteotomy of the left tibia was performed in forty sheep. An external fixator was used to stabilize the osteotomy site. A thin stainless-steel pin was inserted into the bone, 1.0 cm proximal to the osteotomy site. Ultrasound was transmitted through the free end of this pin, with a PZT-4D transducer. In twenty animals, the treated limb received a 200-microsec burst of 1-MHz sine waves repeated at 1 kHz with an average intensity of 30 mW/cm(2) for twenty minutes daily. Twenty other animals underwent the same surgery but did not receive the ultrasound (controls). Animals were killed at seventy-five and 120 days postoperatively. Radiographic evaluation was performed every fifteen days. Mechanical testing and quantitative computed tomography were performed after death. RESULTS: Fractures treated with ultrasound healed significantly more rapidly, as assessed radiographically, than did the controls (seventy-nine compared with 103 days, p = 0.027). On day 75, the mean cortical bone mineral density (and standard deviation) was 781 +/- 52 mg/mL in the treated limbs compared with 543 +/- 44 mg/mL in the control group (p = 0.014), and the average ultimate strength (as assessed with a lateral bending test) was 1928 +/- 167 N in the treated limbs compared with 1493 +/- 112 N in the control group (p = 0.012). No significant differences were noted on day 120. CONCLUSIONS: This study demonstrated that low-intensity transosseous ultrasound can significantly accelerate the fracture-healing process, increase the cortical bone mineral density, and improve lateral bending strength of the healing fracture in a sheep osteotomy model.

Animals↗

PubMed2002

Endoscopic carpal tunnel release: thirteen years' experience with the Chow technique.

The purpose of this single-center study was to evaluate the results of endoscopic carpal tunnel release (ECTR) by using the dual portal Chow technique in a large series of patients. A total of 2,675 procedures in 1,886 patients were performed during a 13-year period. Follow-up evaluation was performed in 2,402 (90%) cases or 1,698 (90%) patients. The success rate was 95% and the recurrence rate was 0.5%. A total of 106 cases (4.5%) were considered failures or had unsatisfactory results. The overall complication rate was 1.1% but no serious complications occurred in this series. The return-to-work status was followed-up in 1,156 patients; 90% of non-worker's compensation patients and 60% of worker's compensation patients returned to work within 4 weeks. This study suggests that ECTR for carpal tunnel syndrome (CTR) is a reliable procedure with a high success rate. Based on our 13 years of experience, we believe that the technique is safe and iatrogenic complications can be avoided with meticulous surgical technique.

Adolescent↗