G. Y. Laflamme

Validity of Goniometric Elbow Measurements: Comparative Study with a Radiographic Method

BackgroundA universal goniometer is commonly used to measure the elbow’s ROM and carrying angle; however, some authors question its poor intertester reliability.Questions/purposesWe (1) assessed the validity of goniometric measurements as compared with radiographic measurements in the evaluation of ROM of the elbow and (2) determined the reliability of both.MethodsThe ROM and carrying angle of 51 healthy subjects (102 elbows) were measured using two methods: with a universal goniometer by one observer three times and on radiographs by two independent examiners. Paired t-test and Pearson’s correlation were used to compare and detect the relationship between mean ROM. The maximal error was calculated according to the Bland and Altman method.ResultsThe intraclass correlation coefficients (ICC) ranged from 0.945 to 0.973 for the goniometric measurements and from 0.980 to 0.991 for the radiographic measurements. The two methods correlated when measuring the total ROM in flexion and extension. The maximal errors of the goniometric measurement were 10.3° for extension, 7.0° for flexion, and 6.5° for carrying angle 95% of the time. We observed differences for maximum flexion, maximal extension, and carrying angle between the methods.ConclusionBoth measurement methods differ but they correlate. When measured with a goniometer, the elbow ROM shows a maximal error of approximately 10°.Clinical RelevanceThe goniometer is a reasonable and simple clinical tool, but for research protocols, we suggest using the radiographic method because of the higher level of precision required.

CT scan assessment of the syndesmosis: a new reproducible method.

Objectives: Anatomic reduction of the fibula with regard to the tibia is the goal when treating syndesmotic injuries. No objective method exists to describe the distal tibiofibular relationship. The primary and secondary objectives of this study was to describe and validate radiologic measurements of the syndesmosis and to establish a set of normal values, respectively. Methods: A set of 6 measurements and 2 angles were defined on axial computed tomography scans. These measures describe distal tibiofibular anatomy in rotation, lateral translation, and anteroposterior position. A series of 100 ankle computed tomography scans were measured by 2 evaluators. Interobserver reliability was assessed on a subset of 30 scans by 3 different evaluators. Measurements were repeated 6 weeks later by 2 evaluators for intraobserver reliability. All correlations were evaluated with intraclass correlation coefficients. Results: Good correlations for nearly all measurements were found, with intraclass correlation coefficients over 0.5. The lateral translation was the most reliable measure with a mean value of 2.8 mm. The mean ratio of anterior tibiofibular distance to posterior tibiofibular distance was 0.54. Proximal to tibial plafond, the fibula is internally rotated 8.7 degrees and at the talar dome level it is in 6.9 degrees of external rotation. Conclusions: Several studies have shown that the reduction of the syndesmosis is essential to restore normal ankle mechanics and prevent secondary degenerative changes. The evaluation criteria developed in this study can give the surgeon a guideline for evaluating syndesmosis anatomy with reliable parameters. Concerning the normal range of motion, our radiologic measurements of 100 normal ankles showed that a significant amount of variability exists in the uninjured distal tibiofibular relationship.

A randomised clinical trial comparing minimally invasive surgery to conventional approach for endoprosthesis in elderly patients with hip fractures.

BACKGROUND In recent years, the concept of minimally invasive surgery has invaded the orthopaedic field and literature on the subject is spawning. Mini-incision surgery for total hip arthroplasty has been studied without a clear consensus on the efficacy, safety and advantage of that technique. To our knowledge, the efficacy and safety of mini-incisions in hip fracture surgery has not been studied in a randomised fashion. METHODS This study is a prospective clinically randomised trial whose primary objective was to demonstrate the safety and efficacy of a single posterior mini-incision approach compared to a standard posterior approach for endoprosthesis in acute femoral neck fractures. The mini-incision was defined as less than 8 cm. 25 patients in the mini-incision surgery (MIS) group and 31 patients in the standard incision group (STD) were available for analysis. The following validated disease-specific outcome instruments were used: the Lower Extremity Measurement (LEM) and the Time Up and Go (TUG). Secondary endpoints of pain, function, and quality of life were assessed by the components of the Harris Hip Score (HHS) and SF-36. Radiographic outcomes were also evaluated as well as the rates of all reported complications and adverse events during the 2 years follow-up. RESULTS There was no significant difference for operative time, blood losses, 72 h postoperative haemoglobin as well as the need for transfusion therapy between the two groups. Also, there was no difference between the groups for postoperative morphine use and pain evaluation with the Visual Analog Scale. The functional assessment using LEM and TUG did not demonstrate any statistically significant difference between mini- and standard incision. However, the HHS and the physical function component of the SF-36 were statistically better at 2 years in favour of the standard incision group. CONCLUSION Based on the results of the present study, we cannot recommend the use of a minimally invasive approach over a standard approach in the implantation of a cemented endoprosthesis.

A new morphological classification for greater tuberosity fractures of the proximal humerus: validation and clinical Implications

In this study, we describe a morphological classification for greater tuberosity fractures of the proximal humerus. We divided these fractures into three types: avulsion, split and depression. We retrospectively reviewed all shoulder radiographs showing isolated greater tuberosity fractures in a Level I trauma centre between July 2007 and July 2012. We identified 199 cases where records and radiographs were reviewed and included 79 men and 120 women with a mean age of 58 years (23 to 96). The morphological classification was applied to the first 139 cases by three reviewers on two occasions using the Kappa statistic and compared with the AO and Neer classifications. The inter- and intra-observer reliability of the morphological classification was 0.73 to 0.77 and 0.69 to 0.86, respectively. This was superior to the Neer (0.31 to 0.35/0.54 to 0.63) and AO (0.30 to 0.32/0.59 to 0.65) classifications. The distribution of avulsion, split and depression type fractures was 39%, 41%, and 20%, respectively. This classification of greater tuberosity fractures is more reliable than the Neer or AO classifications. These distinct fracture morphologies are likely to have implications in terms of pathophysiology and surgical technique.

Direct Reduction Technique for Superomedial Dome Impaction in Geriatric Acetabular Fractures

Summary: The treatment of acetabular fractures in the elderly patients remains challenging. The “Gull Sign,” which was recently described, was 100% predictive of failure of reduction and/or fixation. However, we believe that adequate reduction can be achieved and lead to good functional outcomes. Our technique differs from classic methods because it uses an anterior intrapelvic approach (the modified Stoppa) to obtain direct reduction of the impacted fragments. Access to the impacted superomedial dome is achieved by mobilizing the quadrilateral fragment, thus allowing direct visualization of the impacted articular surface. After reduction, definitive fixation is obtained with 3.5-mm cortical screws positioned in the subchondral bone directly over the Gull fragment. Our technique was performed in 9 patients, with a mean follow-up of 2.8 years. The quality of reduction was within 3 mm in 7 patients (78%). The overall conversion rate to total hip arthroplasty was 33%. All patients undergoing total hip arthroplasty either had initial malreduction or suffered an early loss of reduction. Other complications included 1 case of heterotopic ossification (Brooker type II) and 1 case of deep vein thrombosis. There were no infections. The average Harris Hip Score was 81. Good reduction of superior medial dome impaction can be obtained and maintained in the well-selected geriatric patient. We believe that, appropriately used, this direct reduction technique can be an important adjunct to surgeons dealing with this troublesome fracture.

Heterotopic ossification following total hip replacement for acetabular fractures

Early total hip replacement (THR) for acetabular fractures offers accelerated rehabilitation, but a high risk of heterotopic ossification (HO) has been reported. The purpose of this study was to evaluate the incidence of HO, its associated risk factors and functional impact. A total of 40 patients with acetabular fractures treated with a THR weres retrospectively reviewed. The incidence and severity of HO were evaluated using the modified Brooker classification, and the functional outcome assessed. The overall incidence of HO was 38% (n = 15), with nine severe grade III cases. Patients who underwent surgery early after injury had a fourfold increased chance of developing HO. The mean blood loss and operating time were more than twice that of those whose surgery was delayed (p = 0.002 and p < 0.001, respectively). In those undergoing early THR, the incidence of grade III HO was eight times higher than in those in whom THR was delayed (p = 0.01). Only three of the seven patients with severe HO showed good or excellent Harris hip scores compared with eight of nine with class 0, I or II HO (p = 0.049). Associated musculoskeletal injuries, high-energy trauma and head injuries were associated with the development of grade III HO.The incidence of HO was significantly higher in patients with a displaced acetabular fracture undergoing THR early compared with those undergoing THR later and this had an adverse effect on the functional outcome.

A biomechanical study comparing polyaxial locking screw mechanisms

OBJECTIVE Locking plates have become ubiquitous in modern fracture surgery. Recently, manufacturers have developed locking plates with polyaxial screw capabilities in order to optimise screw placement. It has already been demonstrated that inserting uniaxial locking screws off axis results in weaker loads to failure. Our hypothesis was that even implants specifically designed for polyaxial insertion would experience a drop-off in resistance when using non-perpendicular screws. METHODS Four different types (one monoaxial and three polyaxial locking plates) of readily available small fragment plates were tested. A biomechanical model was developed to test the screws until failure (defined as breakage and rapid loss of >50% force). Screws were inserted at 0, 10 and 15°. RESULTS The standard monoaxial locking mechanism sustained saw a 60% reduction in force (332N vs. 134N) when screws were inserted cross-threaded at 10°. Two polyaxial systems saw similar significant reductions in force of 45% and 34%, respectively at 15°. A third system utilizing an end cap locking mechanism showed highly variable results with large standard deviations. Polyaxial screws showed on average only limited reduction at 10 degrees of insertion angle. CONCLUSION Newer designs of locking plates have attractive properties to allow more surgical options during fixation. However this freedom comes at the price of reduced force. Our results show that the safe zone for inserting these screws is closer to 20°, rather than the 30° indicated by the manufacturers. Also, the various polyaxial locking mechanisms seem to influence the overall resistance of the screws.

Periprosthetic Fractures of the Acetabulum During Cup Insertion: Posterior Column Stability is Crucial

Periprosthetic hip fractures around acetabular components are rare with little information available to guide surgical management of these complex injuries. A retrospective review of intraoperative isolated acetabular periprosthetic fractures from three tertiary surgical units was done. A total of 32 patients were identified with 9 initially missed. Acetabular components were stable (type 1) in 11 patients with no failures; unstable (type 2) in 12 patients and treated with supplemental fixation. Non-union and displacement were correlated with absent posterior column plating. Missed fractures (type 3) had the highest reoperation rate. Anterior patterns all healed, whereas fractures with posterior column instability had a 67% failure rate. Periprosthetic acetabular fracture can heal successfully with posterior column stability. Plating is mandatory for large posterior wall fragments to achieve osteointegration.

Demographic and anthropometric factors affecting elbow range of motion in healthy adults

BACKGROUND To use elbow range of motion routinely as a diagnostic index, it is important to explain the normal variability among the population. Consequently, this study assessed the possible associations between age, sex, laterality, body mass index, joint laxity, level of physical activities, upper limb dimensions, and the elbow range of motion in flexion/extension. MATERIALS AND METHODS Maximal flexion and extension were measured on the lateral radiographs of 102 elbows of 51 volunteers. The difference of range of motion regarding sex and laterality was assessed with Student t tests. The Pearson correlation coefficient was used to evaluate the relationship between elbow mobility and the other factors, and a stepwise multiple regression analysis was performed. RESULTS Among the 51 volunteers, a correlation was found between flexion and body mass index, age, and midbrachial and forearm circumferences (r = -0.234 to -0.594). Age (r = 0.268) and hyperlaxity (r = -0.323) were the only factors associated with a change in elbow extension. No correlation was found between the level of physical activity or with the laterality and changes in elbow mobility. Finally, women presented with more flexion and total elbow range of motion than men. CONCLUSIONS This study confirms the association between various demographic and anthropometric factors and elbow range of motion in healthy adults. Among these, the body mass index and forearm circumference are the most likely responsible for mobility variations among the population.

Locking plate fixation provides superior fixation of humerus split type greater tuberosity fractures than tension bands and double row suture bridges

BACKGROUND This paper aims to determine the strongest fixation method for split type greater tuberosity fractures of the proximal humerus by testing and comparing three fixation methods: a tension band with No. 2 wire suture, a double-row suture bridge with suture anchors, and a manually contoured calcaneal locking plate. METHODS Each method was tested on eight porcine humeri. A osteotomy of the greater tuberosity was performed 50° to the humeral shaft and then fixed according to one of three methods. The humeri were then placed in a testing apparatus and tension was applied along the supraspinatus tendon using a thermoelectric cooling clamp. The load required to produce 3mm and 5mm of displacement, as well as complete failure, was recorded using an axial load cell. FINDINGS The average load required to produce 3mm and 5mm of displacement was 658N and 1112N for the locking plate, 199N and 247N for the double row, and 75N and 105N for the tension band. The difference between the three groups was significant (P<0.01). The average load to failure of the locking plate (810N) was significantly stronger than double row (456N) and tension band (279N) (P<0.05). The stiffness of the locking plate (404N/mm) was significantly greater than double row (71N/mm) and tension band (33N/mm) (P<0.01). INTERPRETATION Locking plate fixation provides the strongest and stiffest biomechanical fixation for split type greater tuberosity fractures.