Augmented Fixation for Fractures of the Appendicular Skeleton.

Despite advances in technology such as locked plating, osteoporotic bone and bone defects remain challenging complications for orthopaedic surgeons. The concept of augmented fixation is useful in these settings. Augmented fixation can be described as improving construct strength and stability by enhancing the surrounding environment. By understanding and using the techniques of alternative fixation strategies, endosteal or medullary support, structural grafting, or the use of bone graft substitutes in combination with standard or integrated fixation, surgeons can improve the chances of success when treating difficult fractures. The purpose of this article is to introduce the reader to the concept of augmented fixation, review strategies for its application, and review applicable published results.

Preexisting Carpal and Carpometacarpal Osteoarthritis Has No Impact on Function after Distal Radius Fractures.

Background Functional outcomes of distal radius fractures vary widely regardless of treatment methods. Purpose This study aims to verify whether preexisting carpal and carpometacarpal (CMC) osteoarthritis (OA) will negatively impact wrist functional outcome in patients with distal radius fractures. Patients and Methods A retrospective case-control study was done using a prospective trauma database. Patients were matched 1:1 in two groups based on the presence of wrist or carpal arthritis (OA). The groups were matched for sex, follow-up, and treatment type. Patients were followed up for a minimum of 1 year and functional outcomes were assessed using validated scores. Results A total of 61 patients were included. Mean age was 63 years (range: 20-85) and average follow-up was 26 months. There were 31 patients in the OA+ group and 30 in the OA- group. Forty-one patients were treated surgically and 20 nonoperatively. None of the patients in the OA- developed OA during follow-up. Both groups were comparable for sex, residual deformity, and follow-up. There was no significant difference for the visual analog scale, Short Form-12, Quick Disability Arm Shoulder Hand, and Patient-rated Wrist Evaluation, or for radiographic outcomes. Conclusion Preexisting OA in the wrist or CMC does not seem to impact outcomes of distal radius fractures, regardless of treatment, age, or sex. Although this is a negative study, the results are important to help counsel patients with distal radius fractures. Further work must be done to identify other potential causes for negative outcomes. Level of Evidence Level III, prognostic study.

Changes in the flexion relaxation response induced by lumbar muscle fatigue.

BACKGROUND: The flexion relaxation phenomenon (FRP) is an interesting model to study the modulation of lumbar stability. Previous investigations have explored the effect of load, angular velocity and posture on this particular response. However, the influence of muscular fatigue on FRP parameters has not been thoroughly examined. The objective of the study is to identify the effect of erector spinae (ES) muscle fatigue and spine loading on myoelectric silence onset and cessation in healthy individuals during a flexion-extension task. METHODS: Twenty healthy subjects participated in this study and performed blocks of 3 complete trunk flexions under 4 different experimental conditions: no fatigue/no load (1), no fatigue/load (2), fatigue/no load(3), and fatigue/load (4). Fatigue was induced according to the Sorenson protocol, and electromyographic (EMG) power spectral analysis confirmed that muscular fatigue was adequate in each subject. Trunk and pelvis angles and surface EMG of the ES L2 and L5 were recorded during a flexion-extension task. Trunk flexion angle corresponding to the onset and cessation of myoelectric silence was then compared across the different experimental conditions using 2 x 2 repeated-measures ANOVA. RESULTS: Onset of myoelectric silence during the flexion motion appeared earlier after the fatigue task. Additionally, the cessation of myoelectric silence was observed later during the extension after the fatigue task. Statistical analysis also yielded a main effect of load, indicating a persistence of ES myoelectric activity in flexion during the load condition. CONCLUSION: The results of this study suggest that the presence of fatigue of the ES muscles modifies the FRP. Superficial back muscle fatigue seems to induce a shift in load-sharing towards passive stabilizing structures. The loss of muscle contribution together with or without laxity in the viscoelastic tissues may have a substantial impact on post fatigue stability.

Postural balance during quiet standing in patients with total hip arthroplasty and surface replacement arthroplasty.

BACKGROUND: Primary total hip arthroplasty leads to better functional capacities but a general weakness of abductor muscles often persists. A larger head component may improve the postural balance in the medial-lateral direction. The aims of this study are (1) to compare postural stability in patients after total hip and surface replacement arthroplasties and (2) to evaluate the effect of the biomechanical reconstruction on postural stability. METHODS: Six months post-surgery, three groups of ten subjects (total hip and surface replacement arthroplasties and control) performed quiet standing tasks in both dual and one leg stance and a hip abductor muscles strength test. The root-mean-square amplitude of centre of pressure and centre of mass displacement in the anterior-posterior and medial-lateral directions were calculated for dual stance task. FINDINGS: Statistical analyses showed greater centre of pressure and centre of mass displacement amplitude in the medial-lateral direction during the dual stance for the total hip arthroplasty compared to the surface replacement and control subjects (P<0.05). All control subjects completed the one leg stance compared to nine in the surface replacement and five in the total hip arthroplasty group. No statistical difference was found between the groups in the hip abductor muscles strength. INTERPRETATION: The better anatomical preservation, absence of femoral stem and the larger bearing component could account for the return to better postural stability in surface replacement patients in comparison to total hip patients. Further studies are needed to determine the impact of each of these factors on the postural balance.

Kinematic and kinetic analysis of a stepping-in-place task in below-knee amputee children compared to able-bodied children.

It has been demonstrated that below-knee amputee (BKA) subjects use specific compensation strategies to overcome their physical limitations. Biomechanical studies emphasize that the motor strategies adopted by BKA adults differ between their amputated limb and their nonamputated limb and from those employed by able-bodied (AB) subjects. The purpose of this investigation was to compare the motor solutions used by control AB and BKA children during a stepping-in-place (SIP) task and to assess how they regulate the coordination of their nonamputated and amputated limbs during this task. Eight BKA children and eight AB children paired for gender, age, weight and height participated in our study. One-way analysis of variances (ANOVAs) were performed on peaks of angular excursion, moment, and power at the hip, knee, and ankle to compare motor strategies between the BKA and AB groups. The main results of our experiment showed that even if BKA and AB children did the task with almost the same kinematics, the kinetic data revealed completely different mechanisms of the two groups to achieve the SIP task, and BKA children had a symmetrical interlimb strategy. SIP, a simple task compared to gait at the level of neuro-musculoskeletal demands, could thus offer a transition task to physical therapists for below-knee recently-amputated children.

Postural control during laparoscopic surgical tasks.

BACKGROUND: Balance control during standing is essential while performing surgery. The postural sway must be controlled to enhance movement accuracy. Postural control was compared between novices and experts during standardized laparoscopic tasks. METHODS: Seven novices with limited exposition to laparoscopy were compared with 7 expert surgeons. The subjects were requested to perform 4 laproscopic tasks on the McGill Inanimate System for Training and Evaluation of Laparoscopic Skills (MISTELS) and a quiet standing task while standing on 2 force platforms. An analysis of variance (ANOVA) with repeated measures was performed to compare groups and the different conditions. Significant level was set at P < .05. RESULTS: The technical requirements of the laparoscopic tasks impacted on postural sway in both anteroposterior and mediolateral directions. Furthermore, results indicate that the experts have a significantly better postural balance for all tasks compared to novices. CONCLUSION: Postural sway increases with the technical requirements of minimally invasive surgery. This study showed that postural control performance while standing improves with laparoscopic expertise.