Evidence Based Development of a Novel Lateral Fibula Plate (VariAx Fibula) Using a Real CT Bone Data Based Optimization Process During Device Development

Development of novel implants in orthopaedic trauma surgery is based on limited datasets of cadaver trials or artificial bone models. A method has been developed whereby implants can be constructed in an evidence based method founded on a large anatomic database consisting of more than 2.000 datasets of bones extracted from CT scans. The aim of this study was the development and clinical application of an anatomically pre-contoured plate for the treatment of distal fibular fractures based on the anatomical database. 48 Caucasian and Asian bone models (left and right) from the database were used for the preliminary optimization process and validation of the fibula plate. The implant was constructed to fit bilaterally in a lateral position of the fibula. Then a biomechanical comparison of the designed implant to the current gold standard in the treatment of distal fibular fractures (locking 1/3 tubular plate) was conducted. Finally, a clinical surveillance study to evaluate the grade of implant fit achieved was performed. The results showed that with a virtual anatomic database it was possible to design a fibula plate with an optimized fit for a large proportion of the population. Biomechanical testing showed the novel fibula plate to be superior to 1/3 tubular plates in 4-point bending tests. The clinical application showed a very high degree of primary implant fit. Only in a small minority of cases further intra-operative implant bending was necessary. Therefore, the goal to develop an implant for the treatment of distal fibular fractures based on the evidence of a large anatomical database could be attained. Biomechanical testing showed good results regarding the stability and the clinical application confirmed the high grade of anatomical fit.

Influence of Partial Lateral Corpectomy with and without Hemilaminectomy on Canine Thoracolumbar Stability: A Biomechanical Study

OBJECTIVE: To analyze the biomechanical changes induced by partial lateral corpectomy (PLC) and a combination of PLC and hemilaminectomy in a T13-L3 spinal segment in nonchondrodystrophic dogs. STUDY DESIGN: In vitro biomechanical cadaveric study. SAMPLE POPULATION: T13-L3 spinal segments (n = 10) of nonchondrodystrophic dogs (weighing, 25-38 kg). METHODS: A computed tomography (CT) scan of each T13-L3 spinal segment was performed. A loading simulator for flexibility analysis was used to determine the range of motion (ROM) and neutral zone (NZ) during flexion/extension, lateral bending, and axial rotation. A servohydraulic testing machine was used to determine the changes in stiffness during compression, dorsoventral, and lateral shear. All spines were tested intact, after PLC in the left intervertebral space of L1-L2, and after a combination of PLC and hemilaminectomy. RESULTS: Statistically significant increases in ROM and NZ (P < .05) were detected during flexion/extension and lateral bending when PLC was performed. A significant increase in ROM (P < .001) was noted during axial rotation and flexion after PLC and hemilaminectomy. Stiffness decreased significantly during compression and dorsoventral shear after each procedure. Decreased stiffness during lateral shear was only significant after a combination of both procedures. CONCLUSION: PLC might lead to some spinal instability; these changes are enhanced when a hemilaminectomy is added.

Triple innominate osteotomy for Legg-Calvé-Perthes disease in children: does the lateral coverage change with time?

Triple innominate osteotomy (TIO) is one of the modalities of surgical containment in Legg-Calvé-Perthes disease (LCPD). However, overcoverage with TIO can lead to pincer impingement.

Single-dose pharmacokinetics and tolerability of oral delta-9- tetrahydrocannabinol in patients with amyotrophic lateral sclerosis

Cannabinoids exert neuroprotective and symptomatic effects in amyotrophic lateral sclerosis (ALS). We assessed the pharmacokinetics (PK) and tolerability of delta-9-tetrahydrocannabinol (THC) in ALS patients.

Lactate, not glucose, up-regulates mitochondrial oxygen consumption both in sham and lateral fluid percussed rat brains

OBJECTIVE: Failure of energy metabolism after traumatic brain injury may be a major factor limiting outcome. Although glucose is the primary metabolic substrate in the healthy brain, the well documented surge in tissue lactate after traumatic brain injury suggests that lactate may provide an energy need that cannot be met by glucose. We hypothesized, therefore, that administration of lactate or the combination of lactate and supraphysiological oxygen may improve mitochondrial oxidative respiration in the brain after rat fluid percussion injury. We measured oxygen consumption (VO2) to determine what effects glucose, lactate, oxygen, and the combination of lactate and oxygen have on mitochondrial respiration in both injured and uninjured rat brain tissue. METHODS: Anesthetized Sprague-Dawley rats were intubated and ventilated with either 0.21 or 1.0 fraction of inspired oxygen (FIO2). Brain tissue from acute sham animals was subjected in vitro to 1.1 mM, 12 mM and 100 mM concentrations of glucose and L-lactate. In another group, injury (fluid percussion injury of 2.5 +/- 0.02 atmospheres) was induced over the left hemisphere. The VO2 of mug amounts of brain tissues were measured in a microrespirometry system (Cartesian diver). RESULTS: The VO2 was found to be independent of glucose concentrations, but dose-dependent for lactate. Moreover, the lactate dependent VO2s were all significantly higher than those generated by glucose. Injured rats on FIO2 0.21 had brain tissue VO2 rates that were significantly lower than those of shams or preinjury levels. In injured rats treated with FIO2 1.0, the reduction in VO2 levels was prevented. Injured rats that received an intravenous infusion of 100 mM lactate had VO2 rates that were significantly higher than those obtained with FIO2 1.0. Combined treatment further boosted the lactate generated VO2 rates by approximately 15%. CONCLUSION: Glucose sustains mitochondrial respiration at a low level "fixed" rate because, despite increasing its concentration nearly 100-fold, it cannot up-regulate VO2 after fluid percussion injury. Lactate produces a dose-dependent VO2 response, possibly enabling mitochondria to meet the increased energy needs of the injured brain.

[Medium-term results after m. vastus medialis obliquus-plasty for lateral patellar dislocation]

Progressive retropatellar arthrosis is often seen in dated rigid distal realignment (i.e. osteotomy of tuberositas) at long-term follow-ups. Therefore, operations for lateral dislocation of the patella are still discussed controversially. Dynamic, proximal realignments seem to have lower rates of arthrosis but higher rates of redislocation. Recently, in anatomic and biomechanic studies, the m. vastus medialis obliquus (vmo) was found to be one of the most important proximal restraints to lateral dislocation of the patella.A total of 28 patients (mean age 21.5 years) were treated between 1994 and 2003 with a plasty of the vmo for lateral patellar dislocation. The technique was performed for most etiologies of femoropatellar instability.For this proximal soft tissue technique, the muscle tendon is detached from its patellar insertion. Subsequently, the tendon is reinserted at the patella 10-15 mm more distally and fixed with Mitek anchors. Full weight bearing in extension is possible immediately after surgery. An active vastus medialis training is started after 6 weeks.Of the patients, 27 were evaluated clinically and radiologically in 2004 (a mean of 5 years postoperatively). A total of 83% of the patients estimated the result to be good or excellent, 10% were satisfied and 7% were discontent. The mean Lysholm-Knee-Score was 83.1 points. Two patients suffered a patella redislocation (7%). A statistically significant improvement of the congruence angle was noted in the radiographs, even in medium-term controls. In 89% of the cases no or only little retropatellar arthrosis was observed. These 5 year results are comparable to those of other techniques for distal or proximal realignments. The rate of redislocation was below average. Compared to the rate of retropatellar arthrosis in long-term results of rigid distal realignment, our patients demonstrated a relative low rate after 5 years. We attribute this to the minimal interference in physiological joint mechanics and to the restored anatomy. In terms of future long-term results, our findings are promising. The idea of a proximal dynamic stabilization and the causal operative approach at the origin of pathology using vmo-plasty was confirmed in recent anatomic and biomechanic studies. Over or under correction of soft tissues could be adapted. More rigid techniques of distal realignment do not allow an adaptation to this extent and can lead to prearthrotic hyperpression in the medial femoropatellar and femorotibial joints.

Association of a large lateral extension of the acromion with rotator cuff tears

BACKGROUND: Factors predisposing to tearing of the rotator cuff are poorly understood. We have observed that the acromion of patients with a rotator cuff tear very often appears large on anteroposterior radiographs or during surgery. The purpose of this study was to quantify the lateral extension of the acromion in patients with a full-thickness rotator cuff tear and in patients with an intact rotator cuff. METHODS: The lateral extension of the acromion was assessed on true anteroposterior radiographs made with the arm in neutral rotation. The distance from the glenoid plane to the lateral border of the acromion was divided by the distance from the glenoid plane to the lateral aspect of the humeral head to calculate the acromion index. This index was determined in a group of 102 patients (average age, 65.0 years) with a proven full-thickness rotator cuff tear, in an age and gender-matched group of forty-seven patients (average age, 63.7 years) with osteoarthritis of the shoulder and an intact rotator cuff, and in an age and gender-matched control group of seventy volunteers (average age, 64.4 years) with an intact rotator cuff as demonstrated by ultrasonography. RESULTS: The average acromion index (and standard deviation) was 0.73 +/- 0.06 in the shoulders with a full-thickness tear, 0.60 +/- 0.08 in those with osteoarthritis and an intact rotator cuff, and 0.64 +/- 0.06 in the asymptomatic, normal shoulders with an intact rotator cuff. The difference between the index in the shoulders with a full-thickness supraspinatus tear and the index in those with an intact rotator cuff was highly significant (p < 0.0001). CONCLUSIONS: A large lateral extension of the acromion appears to be associated with full-thickness tearing of the rotator cuff.

Supramalleolar lateral closing wedge osteotomy for the treatment of varus ankle arthrosis

BACKGROUND: Medial ankle joint pain with localized cartilage degeneration due to medial joint overload in varus malalignment of the hindfoot lends itself to treatment by lateral closing wedge supramalleolar osteotomy. METHODS: From 1998 to 2003, nine patients between the ages of 21 to 59 years were operated. The etiology of the malalignment and degeneration was posttraumatic in eight and childhood osteomyelitis in one. Preoperative and postoperative standing radiographs were analyzed to determine the correction of the deformity and the grade of degeneration. Function and pain were assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale. The average followup was 56 (range 15 to 88) months. RESULTS: The average time to osseous union was 10 +/- 3.31 weeks. There were no operative or postoperative complications. The average AOFAS score improved from 48 +/- 16.0 preoperatively to 74 +/- 11.7 postoperatively (p<0.004). The average pain subscore improved from 16 +/- 8.8 to 30 +/- 7.1 (p<0.008). The average tibial-ankle surface angle improved from 6.9 +/- 3.8 degrees of varus preoperatively to 0.6 +/- 1.9 degrees of valgus postoperatively (p<0.004). In the sagittal plane, the tibial-lateral-surface angle remained unchanged. At the final followup, two patients showed progression of radiographic ankle arthrosis grades. In one patient, it rose from grade 0 to I. In the other patient it advanced from grade II to III, with subsequent ankle arthrodesis required 16 months after the index procedure. Seven patients returned to their previous work. CONCLUSIONS: Lateral supramalleolar closing wedge osteotomy was an easy and safe procedure, effectively correcting hindfoot malalignment, relieving pain, restoring function, and halting progression of the degeneration in the short-term to mid-term in seven of nine patients.

Outcome and patients' satisfaction after functional treatment of acute lateral ankle injuries at emergency departments versus family doctor offices

BACKGROUND: In some Western countries, more and more patients seek initial treatment even for minor injuries at emergency units of hospitals. The initial evaluation and treatment as well as aftercare of these patients require large amounts of personnel and logistical resources, which are limited and costly, especially if compared to treatment by a general practitioner. In this study, we investigated whether outsourcing from our level 1 trauma center to a general practitioner has an influence on patient satisfaction and compliance. METHODS: This prospective, randomized study, included n = 100 patients who suffered from a lateral ankle ligament injury grade I-II (16, 17). After radiological exclusion of osseous lesions, the patients received early functional treatment and were shown physical therapy exercises to be done at home, without immobilization or the use of stabilizing ortheses. The patients were randomly assigned into two groups of 50 patients each: Group A (ER): Follow-up and final examination in the hospital's emergency unit. Group B (GP): Follow-up by general practitioner, final examination at hospital's emergency unit. The patients were surveyed regarding their satisfaction with the treatment and outcome of the treatment. RESULTS: Female and male patients were equally represented in both groups. The age of the patients ranged from 16 - 64 years, with a mean age of 34 years (ER) and 35 years (GP). 98% (n = 98) of all patients were satisfied with their treatment, and 93% (n = 93) were satisfied with the outcome. For these parameters no significant difference between the two groups could be noted (p = 0.7406 and 0.7631 respectively). 39% of all patients acquired stabilizing ortheses like ankle braces (Aircast, Malleoloc etc.) on their own initiative. There was a not significant tendency for more self-acquired ortheses in the group treated by general practicioners (p = 0,2669). CONCLUSION: Patients who first present at the ER with a lateral ankle ligament injury grade I-II can be referred to a general practitioner for follow-up treatment without affecting patient satisfaction regarding treatment and treatment outcome.

Lateral external fixation: a new surgical technique for displaced unreducible supracondylar humeral fractures in children

BACKGROUND: Percutaneous Kirschner wire fixation represents the classic treatment for displaced supracondylar humeral fractures in childhood. This type of treatment first requires satisfactory reduction of the fracture. Failure to achieve a satisfactory reduction or inadequate stabilization can result in instability of the fracture fragments, which can result in either an unsatisfactory cosmetic or functional outcome. In our experience, these problems can be overcome with the use of a small lateral external fixator. METHODS: Between 1999 and 2005, thirty-one of 170 Gartland type-III supracondylar humeral fractures were treated with a lateral external fixator. The outcome of treatment was analyzed with regard to limb alignment, elbow movement, cosmetic appearance, and patient satisfaction. RESULTS: In twenty-eight of the thirty-one patients, a satisfactory reduction was achieved with closed methods. All children except one had a normal or good range of movement. The cosmetic result was excellent in all cases. All of the children and their parents stated that they would choose this treatment again. CONCLUSIONS: The use of a small lateral external fixator seems to be a safe alternative for the treatment of displaced supracondylar fractures of the humerus when a closed reduction appears to be unattainable by means of manipulation alone or when sufficient stability is not achieved with standard methods of Kirschner wire fixation.