Ropivacaine alters the mechanical properties of hamstring tendons: In vitro controlled mechanical testing of tendons from living donors

OBJECTIVE

Intraarticular or periarticular injection of ropivacaine (RI) is an element of current knee surgery practices. The goal of this study was to determine the effects of RI on the mechanical properties of hamstring tendons. We hypothesized that RI would have a detrimental effect on the mechanical properties of periarticular soft tissues METHODS: A tensile test to failure was performed on 120 hamstring tendon segments harvested during ACL reconstruction surgery in 120 patients. Two sets of tensile tests were done. The first evaluated the effect of RI itself on the mechanical properties of tendons: 30 samples were soaked for 1hour in a 2% RI solution and compared to 30 samples soaked in a saline solution (control group). The second evaluated the effect of RI concentration on the mechanical properties of hamstring tendons: 30 samples were soaked for 1hour in a 2% RI solution and 30 samples were soaked in a 7.5% RI solution.

RESULTS

In the first test, 29 samples from each group were analyzed as two samples (one in each group) failed at the grip interface. The specimens exposed to 2% RI had lower ultimate tensile strength (Δ=4.4MPa, P=0.001), strain energy (Δ=13MPa, P=0.001) and Young's modulus (Δ=1.6MPa, P=0.02) than the specimens in the control group. There was no significant difference in the strain at failure between groups (Δ=5%, P=0.3). In the second test, one specimen from the 7.5% RI group failed during the preloading and was excluded. There was no significant difference in terms of the load at failure and ultimate tensile stress (Δ=0.45MPa, P=0.6) and strain energy (Δ=0.49MPa, P=0.49) between the two groups. There were significant differences in terms of elongation at failure (Δ=28%, P=0.0003) and Young's modulus (Δ=2.6MPa, P=0.005), with the specimens exposed to 7.5% RI undergoing greater deformation and having a lower Young's modulus.

DISCUSSION

While local RI injections are widely performed in clinical practice, the results of this in vitro study point to short-term alterations of the mechanical properties of hamstring tendons. If these results hold in vivo, this could lead to weakness of the soft tissues exposed to this product, particularly the tendons and ligaments around the injection area.

LEVEL OF EVIDENCE

Experimental study. Level 1.

Non lethal Raine syndrome and differential diagnosis

Raine syndrome is a rare autosomal recessive bone dysplasia characterized by characteristic facial features with exophthalmos and generalized osteosclerosis. Amelogenesis imperfecta, hearing loss, seizures, and intracerebral calcification are apparent in some affected individuals. Originally, Raine syndrome was originally reported as a lethal syndrome. However, recently a milder phenotype, compatible with life, has been described. Biallelic variants inFAM20C, encoding aGolgi casein kinase involved in biomineralisation, have been identified in affected individuals. We report here a consanguineous Moroccan family with two affected siblingsa girl aged 18 and a boy of 15years. Clinical features, including learning disability, seizures and amelogenesis imperfecta, initially suggested a diagnosis of Kohlschutter-Tonz syndrome. However,a novel homozygous FAM20Cvariantc.676T > A, p.(Trp226Arg) was identified in the affected siblings. Our report reinforces that Raine syndrome is compatible with life, and that mild hypophosphatemia and amelogenesis imperfecta are key features of the attenuated form.

3D templating and patient-specific cutting guides (Knee-Plan) in total knee arthroplasty: postoperative CT-based assessment of implant positioning

INTRODUCTION

The precision of bone cuts and the positioning of components influence the functionality and longevity of total knee arthroplasty (TKA). The objective of this study was to evaluate the results of TKA, performed after 3D preoperative templating, with the prosthesis implanted using custom cutting guides (Knee-Plan system, Symbios Orthopédie SA).

MATERIAL AND METHODS

This prospective study investigated 107 TKAs. Three-dimensional preoperative templating was carried out on the surface views and CT views to analyze the deformation of the lower limb and plan the implantation. The components were positioned in an individualized manner to realign the lower limb and provide ligament balance based on bone landmarks. Final component positioning was analyzed in the three planes with a postoperative CT scan. The preoperative and 1 year follow-up IKS and WOMAC scores were collected and compared.

RESULTS

All the cutting guides were stable and functional. Femoral component planning was reproduced with 0 ± 2 precision in the frontal plane (94%± 3), 2 ± 3 in the sagittal plane, and 0 ± 2 in the transverse plane. The precision of the tibial component was reproduced with 0 ± 2 precision in the frontal plane (93%± 3) and 0 ± 4 in the sagittal plane. The HKA angle increased from 177 ± 7 preoperatively to 180 ± 3 at 1 year of follow-up. The IKS and WOMAC scores were significantly improved at 1 year (P<0.0001).

CONCLUSION

The Knee-Plan system can be a realistic, simple, and reliable alternative to conventional cutting guides and to computer-assisted surgery for TKA implantation.

LEVEL OF EVIDENCE

IV; prospective cohort study.

The contribution of MRI to the diagnosis of traumatic tears of the anterior cruciate ligament

When faced with a clinical suspicion of knee ligament injury, MRI nowadays has a central role in the diagnostic strategy. In particular, it is essential for assessing the cruciate ligaments and any associated meniscal tears. The objective of this review is to present the various direct and indirect MRI signs of tearing of the anterior cruciate ligament (ACL) and then describe the lesions associated with it. The anatomical and clinical aspects are also discussed so that the contribution of MRI to the diagnosis and therapeutic management of an ACL tear can be better understood.

[Cardiac complications associated with organophosphate poisoning]

INTRODUCTION

The clinical picture of organophosphate poisoning is dominated by respiratory and neurological signs. Cardiac complications are rare, serious and little known by clinicians.

OBSERVATION

F.B, 17 years, was addressed intubated, at the emergencies after an organosphorus poisoning. At admission, the patient was comatose with a muscarinic syndrome. Her hemodynamic was stable. Chest radiography and ECG of admission were normal. A gastric washing and a treatment by atropine were quickly started. The toxicological analysis of gastric liquid showed presence of malathion. After 20hours, the patient presented a cardiogenic shock. Chest radiography showed signs of acute pulmonary edema and ECG: a circumferential endocardic ischaemia. In spite of vasopressors and positive inotropic treatment, the patient quickly died. The autopsies revealed multiple necrosis of the heart.

DISCUSSION

The cardiac symptoms are caused by many mechanisms often associated. The cardiac attack appears primarily by many electrocardiographic modifications: arrhythmias, disturb of repolarisation, conduction's disorder... On the hemodynamic plan, a circulatory insufficiency is possible. The ventricular arrhythmias, which are not treated by lidocaine or electric cardioversion are treated effectively by injection of isoproterenol and/or ventricular stimulation, and recently by the use of magnesium salts.

CONCLUSION

If the clinical picture of the IOP is dominated by neurological and respiratory signs, it is always necessary to remember the possibility of cardiac complications (early or late) whose pronostic is very often bad.

La pancréatite post-traumatique : à propos de quatre cas

The post-traumatic pancreatitis is the main reason of mortality in the traumatisms of the pancreas, its concurrence is related to the lesions of the pancreatic channels. It represents only 1% of the pancreatitis. In a descriptive retrospective study, four cases of post-traumatic pancreatitis are described.

[Evaluation of bone mineral density in hyperthyroid patients before and after medical therapy]

Osteoporosis is a common complication of hyperthyroidism, but it is not often evaluated. The aim of this study is to examine bone mineral density (BMD) (dual energy X-ray absorptiometry: DEXA) in lumbar spine (L1-L4), femoral neck (FN) and Ward's triangle (TW) in 45 hyperthyroid patients (group A: n 25 active hyperthyroidism, group B: n 20 controlled hyperthyroidism on medical therapy, after a mean of 7 months of euthyroidism), compared to control group (group C: n 22). These 3 groups are adjusted by age, sex, menopausal status and BMI. In hyperthyroid patients (group A), as compared to the control group, we noticed a significant reduction of BMD (z score) in different sites, more markedly in the lumbar spine (p L1-L4: 0,005; p FN: 0,011; p TW: 0,019). In group A, no differences were found between BMD values after adjustment for Z score whatever the menopausal status (p L: 0.12; p FN: 0.33; p TW: 0.09) and degree ofhyperthyroidism (p L: 0.48; p FN: 0.41; p TW: 0.21). The degree of BMD in group B patients was different from that of patients in group A (p L: 0.37; p FN: 0.28; p TW: 0.31). and was significantly lower than in those of group C except for the TW (p L: 0.009; p CF: 0.038; p TW: 0.068). We conclude that it is important to consider that after reaching euthyroidism hyperthyroidism patients present a bone risk.

["Isolated" injury of the posterior cruciate ligament. Surgical treatment of isolated posterior cruciate ligament tears: a multicentric retrospective study of 103 patients]

PURPOSE OF THE STUDY

We present a retrospective multicentric series of carefully selected patients presenting "isolated" laxity of the posterior cruciate ligament.

MATERIAL AND METHODS

The series included 103 patients who were reviewed clinically (with a dedicated review chart) and radiographically with measurement of posterior laxity (Telos 15 kg).

RESULTS

In these patients with an isolated injury of the PCL (without associated injury of the peripheral ligament)

DISCUSSION

The short follow-up of this series (four years) does not enable an assessment of the risk or benefit of PCL ligamentoplasty for arthrosic knees.

[Cerebellum abscess: first demonstration of undiagnosed infective endocarditis in an adult with corrected transposition arteries]

Neurological complications occur in approximately 30% of all patients with infective endocarditis and represent a major factor associated with an increased mortality rate. Third of these complications is represented by cerebral embolism, followed by mycotic aneurysm, meningitis or meningoencephalitis. Brain abscesses are rare; their localization to the cerebellum is exceptional. A case of cerebellum abscess occurring in a 34-year-old patient with non-operated corrected transposition of the great arteries is reported. Occurrence of this abscess was the first demonstration of undiagnosed infective endocarditis.

[Haemocholecyst: a rare complication of anticoagulant treatment]

We report a case of a 50-year-old woman, taking antivitamin K for double mitro-aortic valvular replacement, having presented a clinical picture of acute cholecystitis with marked hypotension. The radiological and biologic exams showed a deep hypocoagulability, vesicular gallstones, a haemoperitoneum and retroperitoneal haematoma. After correction of biological anomalies, the patient was operated. The gallbladder was distended containing large clots and four stones without any evidence of perforation. One of the gallstones led to cystic duct obstruction. Haemocholecyst is a rare complication of anticoagulant therapy, which may occur in the setting of gallbladder stones. The usual complication was the vesicular perforation. In spite of its rarity, haemocholecyst should be suspected when an anticoagulant treated patient presents symptoms of acute cholecystis with or without haemorrhagic shock.

Reconstruction du ligament croisé antérieur par greffe de tendons de la patte d’oie à un ou à deux faisceaux

PURPOSE OF THE STUDY

We worked with cadaver specimens to evaluate control of anterior knee laxity after reconstruction of the anterior cruciate ligament (ACL) comparing double two-strand anterolateral and posteromedial reconstruction with the classical four-strand technique. We hypothesized that the double reconstruction would provide better control of anterior laxity in both flexion and extension.

MATERIAL AND METHODS

Sixteen cadaver knees were randomly assigned to reconstruction technique. Anterior tibial translation was measured with an arthrometer (Rolimeter) at maximal manual tension at 20 degrees, 60 degrees and 90 degrees flexion on the intact knee, after section of the ACL and after arthroscopic reconstruction using either the classical four-strand hamstring technique or a double two-strand anteromedial and posterolateral technique. An EndoButtonCL was used for the femoral fixation and a interference screw with staples for the tibial fixation. Variation in the length of each construct was measured between 0 degrees and 90 degrees flexion.

RESULTS

In the single reconstruction group, the length of the graft varied by 0.5 +/- 0.7 mm between 0 degrees and 90 degrees flexion. In the double reconstruction group, the length varied by 0.5 +/- 0.9 mm for the anteromedial construct and 3.4 +/- 0.5 mm for the posterolateral construct. When studied with an intact ACL, anterior laxity of the 16 knees was 3.2 +/- 1.1, 3.5 +/- 1.5 and 2.6 +/- 1.1 mm at 20 degrees, 60 degrees, and 90 degrees respectively. After section of the ACL, laxity increased significantly at all angles: 9.4 +/- 3.3, 6.1 +/- 2.5 and 6.8 +/- 2.9 at 20 degrees, 60 degrees, and 90 degrees respectively. After classical four-strand single graft reconstruction, the residual anterior laxity was 3.7 +/- 0.9, 3.1 +/- 1.1, and 2.3 +/- 1.6 mm at 20 degrees, 60 degrees, and 90 degrees flexion. Statistical analysis using parametric or non-parametric tests as appropriate showed a significant difference in laxity at 20 degrees, 60 degrees, and 90 degrees of flexion between knees with a cut ACL and knees with reconstructed ACL. At 20 degrees flexion, residual laxity was greater after single-construct reconstruction. At 60 degrees and 90 degrees there was no significant difference in anterior translation of the tibia in knees with intact or reconstructed ACL. After reconstruction with the dual-construct technique, laxity was 3.4 +/- 1.3, 2.6 +/- 1.5, and 2.4 +/- 1.2 mm at 20 degrees, 60 degrees and 90 degrees flexion respectively. Laxity was significantly greater with a cut ACL than after reconstruction at 20 degrees, 60 degrees, and 90 degrees flexion, but there was no significant difference in anterior translation of the tibia at 20 degrees, 60 degrees, and 90 degrees flexion between knees with an intact and a reconstructed ACL.

DISCUSSION

These results based on a clinical evaluation measuring anterior translation of the tibia with an arthrometer are in agreement with results in the literature using robots. Compared with the classical technique, reconstruction of the ACL with a dual-construct technique provides a statistically significant improvement in control of anterior tibial translation at 20 degrees of flexion. The advantage of the dual anteromedial and posteriolateral construct technique is thus not found in the control of anterior laxity but rather in control of rotation laxity.

CONCLUSION

Reconstruction of the ACL with a two-bundle graft technique provides control of anterior laxity at 20 degrees, 60 degrees, and 90 degrees flexion similar to that observed in knees with an intact ACL while the single construct technique re-establishes physiological laxity at 60 degrees and 90 degrees only. This improved control of anterior laxity with the two-bundle reconstruction is a small improvement regarding anterior laxity, the more potential advantage concerning rotational stability.

[Traumatic thrombosis of the inferior vena cava]

Traumatic thrombosis of vena cava is rare. Thrombosis of the inferior vena cava diagnosed by uroscanner after blunt abdominal trauma involving the kidney is reported. The Doppler exam confirmed the floating character of the clot. Three days after the initiation of anticoagulant therapy, the thrombus disappeared without any clinical or radiological signs of pulmonary embolism. Fifteen cases of traumatic thrombosis of the inferior vena cava have been described in the literature. Mechanisms, clinical pictures and the management are discussed.

Syndrome d’asphyxie traumatique ou syndrome de Perthes. À propos de six cas

Perthe's syndrome or traumatic asphyxia is a clinical syndrome associating cervicofacial cyanosis, petechia and subconjonctival hemorrhage to neurological symptoms. This syndrome appears after severe and transient compressive blunt chest injury. A Valsalva maneuver is necessary before thoracic compression for the development of this syndrome. The treatment includes rapid chest decompression and cardiopulmonary resuscitation. The prognosis is good but a prolonged thoracic compression could lead to cerebral anoxia and neurological sequelae. We report six cases of Perthe's syndrome most of them resulting from thoracic compression after road traffic accidents. All of them made a good prognosis.

[Tension pneumopericardium: a rare complication after thoracic stab wound]

The authors report a case involving a patient with thoracic stab wound. The patient developed tension pneumopericardium with acute cardiac tamponade. The clinical and radiological features of tension pneumopericardium and its treatment are discussed.

[Arthroscopic reconstruction of the anterior cruciate ligament using double anteromedial and posterolateral bundles]

We propose a method for repairing the anterior cruciate ligament which takes advantage of the multifascular nature of the ligament to achieve better physiological anteroposterior and rotational stability compared with conventional methods. Arthroscopic reconstruction of the anteromedial and posterolateral bundles of the ligament closely reproduces normal anatomy. We have used this technique in 92 patients with anterior cruciate ligament laxity and present here the mid-term results. The hamstring tendons (gracilis and semitendinosus) are harvested carefully to obtain good quality grafts. Arthroscopic preparation of the notch allows careful cleaning of the axial aspect of the lateral condyle; it is crucial to well visualize the region over the top and delimit the 9 h-12 h zone for the right knee or the 12-15 h zone for the left knee. The femoral end of the anteromedial tunnel lies close to the floor of the intercondylar notch, 5 to 10 mm in front of the posterior border of the lateral condyle, at 13 h for the left knee and 11 h for the right knee. The femoral end of the posterolateral tunnel lies more anteriorly, at 14 h for the left knee and 10 h for the right knee. The tibial end of the posterolateral tunnel faces the anterolateral spike of the tibia. The tibial end of the anteromedial tunnel lies in front of the apex of the two tibial spikes half way between the anteromedial spike and the anterolateral spike, 8 mm in front of the protrusion of the posteriolateral pin. The posterolateral graft is run through the femoral and tibial tunnels first. A cortical fixation is used for the femoral end. The femoral end of the anteromedial graft is then fixed in the same way. The tibial fixation begins with the posterolateral graft with the knee close to full extension. The anteromedial graft is fixed with the knee in 90 degrees flexion. Thirty patients were reviewed at least six months after the procedure. Mean age was 28.2 years. Mean overall IKDC score was 86% (36% A and 50% B). Gain in laxity was significant: 6.53 preoperatively and 2.1 postoperatively. Most of the patients (86.6%) were able to resume their former occupation 2 months after the procedure. The different components of the anterior cruciate ligament and their respective functions have been the object of several studies. The anteromedial bundle maintains joint stability during extension and anteroposterior stability during flexion. The posterolateral bundle contributes to the action of the anteromedial bundle with an additional effect due to its position: rotational stability during flexion. In light of the multifascicular nature of the anterior cruciate ligament and the residual rotational laxity observed after conventional repair, our proposed method provides a more anatomic reconstruction which achieves better correction of anteroposterior and rotational stability. This technique should be validated with comparative trials against currently employed methods.

[Interest in wrist arthroscopy for treatment of articular fractures of the distal radius: report of 27 cases]

We report our results of treatment of intra articular distal radius fracture assisted by wrist arthroscopy. Twenty six patients (15 men and 11 women) were treated using this technique. All the patients were operated on under regional anaesthesia, the elbow flexed to 90 degrees, and in-line traction applied using "Japanese" fingers traps (4 to 6 kgs). After articular cleansing, reduction under arthroscopic and fluoroscopic control was carried out using K-wires. All fractures were intra articular and in four cases of fractures with four fragments, it was necessary to combine a volar plate with the K-wires. There were 21 associated ligament injuries (seven TFCC tears, four lunotriquetral ligament injuries and ten scapholunate injuries of which four necessitated pinning). Our average follow-up time was 16 months (6-26 months). There was absence of pain in 23 cases and the results were good for wrist motion and strength. We did not experienced any severe secondary displacement. Eighteen excellent, seven good results and one average result were obtained. The quality of these functional and anatomical results seems to be directly linked to the quality of reduction obtained under arthroscopy and the quality of internal fixation carried out under traction.

[Puffer fish poisoning]

We report three cases of a collective tetrodotoxin poisoning, after ingestion of puffer fish eggs. This neurotoxin is the most potent membrane stabilizer, blocking the nervous conduction and resulting in death from respiratory paralysis in case of massive ingestion. The father died at admission, the mother and her daughter presented an acute respiratory failure and a flaccid tetraplegia, with favourable outcome after 24 hours.

[Myocardial rhabdomyolysis following paraphenylene diamine poisoning]

Acute intoxication with paraphenylene diamine, a mineral compound used as hair dye, associated asphyxia due to cervical oedema and rhabdomyolysis. We report the case of a patient with lethal cardiogenic shock secondary to myocardial rhabdomyolysis confirmed by a postmortem biopsy.

[Apropos of a case of acute pancreatitis revealing cystic dilatation of the common bile duct]

Dilatation of the common bile duct is rarely caused by cystic formations. Though the pathogenesis is uncertain, congenital disorders have been suggested. Most cases are observed in small children (80% female predominance) with only 20% of the cases reported in adults. Clinical signs vary. Recurrent acute pancreatitis has been reported but is rare. New imaging techniques using CT-scan cholangiography and sometimes MR cholangiography have greatly improved the diagnostic approach. MR of the bile ducts is a recent noninvasive technique enabling an analysis of the biliopancreatic ducts without contrast injection into the bile. To our knowledge, cystic dilatation of the common bile duct has not been previously reported in the literature. We report an interesting case in a 25-year-old woman who developed an episode of acute pancreatitis during the post partum period. We describe the clinical aspects and the different imaging findings, including magnetic resonance cholangiography results.

[Pneumocephalus: a prognostic factor in head injuries. Results of a retrospective study of 167 patients]

Presence of air within the cranial cavity has been described by several authors. Little attention has been paid to its significance. The goal of this study was to analyse the clinical characteristics and the evolution of patients with pneumocephalus. We reviewed the brain computed tomography scans of 167 consecutive head injury patients who were hospitalized between January 1992 and December 1993. This retrospective study revealed intracranial air in 33 cases (19%). The analysis of clinical characteristics showed that in the initial period the neurologic status was better in patients with pneumocephalus. However, 48 hours later, the proportion of patients presenting a deep coma increased We conclude that pneumocephalus is a significant risk factor in head injury patients.

[Ultrasonic diagnosis of renal lymphoma in children. A series of 18 cases]

Ultrasound tomography imaging is a very effective diagnostic examination for lymphoma of the kidneys, organs which are frequently the site of these tumors (51,5% of cases). A total of 18 cases of renal lymphoma explored by ultrasound tomography over the last 2 years were reviewed, the first patients seen in this series also undergoing intravenous urography and two others a CT scan. In most cases diagnosis from ultrasound imaging was based on findings typical of renal lymphoma and on the almost constant detection of other parenchymatous localizations (liver, spleen, pancreas) or lymph node and/or serous lesions. Tumors were bilateral in 13 cases and unilateral in 5. Ultrasound images showed: a) nephromegaly that was usually bilateral (9 cases) or sometimes unilateral (2 cases), while the kidney or kidneys were of normal size in 4 patients; b) the almost constant presence of hypoechogenic nodules scattered throughout the kidney or kidneys (16 cases); c) global hypoechogenicity of the kidney or kidneys (3 cases)--a sign not reported it the literature--; d) hydronephrosis that was either isolated (2 cases) or associated with the renal lymphomatous lesion (3 cases). The diagnostic reliability, cost and safety of ultrasound imaging make in the examination of choice for the exploration of this affection.

[Supra-umbilical laparotomies and perturbed pulmonary blood oxygenation (author's transl)]

Pulmonary blood flow and ventilation were studied in twenty three patients after supra-umbilical laparotomy by means of samplings of blood gases and expiratory air content, spirometry, and pneumotachography. Although ventilatory perturbations predominate (notably, a lessened tidal volume and an amputation of the residual functional capacity they are found in conjunction with perfusion anomalies, an shown by the study of O2 and CO2 ductances). The PCO2/PO2 diagram of Rahn and Fenn further illustrates these perfusion alterations; in addition, it gives an impression of the metabolic orientation of the patients in the early post-operative period. Several physiopathological notions are derived from the study, as well as some therapeutic proposals.