G. Lullini

Validation of the angular measurements of a new inertial-measurement-unit based rehabilitation system: comparison with state-of-the-art gait analysis

BackgroundSeveral rehabilitation systems based on inertial measurement units (IMU) are entering the market for the control of exercises and to measure performance progression, particularly for recovery after lower limb orthopaedic treatments. IMU are easy to wear also by the patient alone, but the extent to which IMU’s malpositioning in routine use can affect the accuracy of the measurements is not known. A new such system (Riablo™, CoRehab, Trento, Italy), using audio-visual biofeedback based on videogames, was assessed against state-of-the-art gait analysis as the gold standard.MethodsThe sensitivity of the system to errors in the IMU’s position and orientation was measured in 5 healthy subjects performing two hip joint motion exercises. Root mean square deviation was used to assess differences in the system’s kinematic output between the erroneous and correct IMU position and orientation.In order to estimate the system’s accuracy, thorax and knee joint motion of 17 healthy subjects were tracked during the execution of standard rehabilitation tasks and compared with the corresponding measurements obtained with an established gait protocol using stereophotogrammetry.ResultsA maximum mean error of 3.1 ± 1.8 deg and 1.9 ± 0.8 deg from the angle trajectory with correct IMU position was recorded respectively in the medio-lateral malposition and frontal-plane misalignment tests. Across the standard rehabilitation tasks, the mean distance between the IMU and gait analysis systems was on average smaller than 5°.ConclusionsThese findings showed that the tested IMU based system has the necessary accuracy to be safely utilized in rehabilitation programs after orthopaedic treatments of the lower limb.

Functional evaluation of patients treated with osteochondral allograft transplantation for post-traumatic ankle arthritis: One year follow-up

Severe post-traumatic ankle arthritis poses a reconstructive challenge in active patients. Whereas traditional surgical treatments, i.e. arthrodesis and arthroplasty, provide good pain relief, arthrodesis is associated to functional and psychological limitations, and arthroplasty is prone to failure in the active patient. More recently the use of bipolar fresh osteochondral allografts transplantation has been proposed as a promising alternative to the traditional treatments. Preliminary short- and long-term clinical outcomes for this procedure have been reported, but no functional evaluations have been performed to date. The clinical and functional outcomes of a series of 10 patients who underwent allograft transplantation at a mean follow-up of 14 months are reported. Clinical evaluation was performed with the AOFAS score, functional assessment by state-of-the-art gait analysis. The clinical score significantly improved from a median of 54 (range 12-65) pre-op to 76.5 (range 61-86) post-op (p=0.002). No significant changes were observed for the spatial-temporal parameters, but motion at the hip and knee joints during early stance, and the range of motion of the ankle joint in the frontal plane (control: 13.8°±2.9°; pre-op: 10.4°±3.1°, post-op: 12.9°±4.2°; p=0.02) showed significant improvements. EMG signals revealed a good recovery in activation of the biceps femoris. This study showed that osteochondral allograft transplantation improves gait patterns. Although re-evaluation at longer follow-ups is required, this technique may represent the right choice for patients who want to delay the need for more invasive joint reconstruction procedures.

In shoe pressure measurements during different motor tasks while wearing safety shoes: The effect of custom made insoles vs. prefabricated and off-the-shelf

Health and safety regulations in many countries require workers at risk to wear safety shoes in a factory environment. These shoes are often heavy, rigid, and uncomfortable. Wearing safety shoes daily leads to foot problems, discomfort and fatigue, resulting also in the loss of numerous working days. Currently, knowledge of the biomechanical effects of insoles in safety shoes, during working activities, is very limited. Seventeen workers from a metalworking factory were selected and clinically examined for any foot conditions. Workers feet were 3D scanned, with regards to their plantar view, and the images used to design 34 custom-insoles, based on foot and safety shoe models. Three insoles were blind-tested by each worker: custom (CUS); prefabricated with the safety-shoe (PSS), and off-the-shelf (OTS). Foot-to-insole pressure distribution was measured in seven motor tasks replicating typical working activities: single and double-leg standing; weight lifting; stair ascending and descending; normal and fast walking. Wearing CUS within safety shoes resulted in a greater uniform pressure distribution across plantar regions for most of the working activities. Peak pressure at the forefoot during normal walking was the lowest in the custom insole (CUS 275.9±55.3kPa; OTS 332.7±75.5kPa; PSS 304.5±54.2kPa). Normal and fast walking were found to be the most demanding activities in terms of peak pressure. Wearing safety shoes results in high pedobarographic parameters in several foot regions. The use of custom insoles designed on the foot morphology helps decrease peak pressure and pressure-time integral compared to prefabricated featureless insoles.

Postoperative wound management with negative pressure wound therapy in knee and hip surgery: a randomised control trial

OBJECTIVE To compare the effectiveness in wound healing of negative pressure wound therapy (NPWT) versus a standard dressing in patients who underwent hip or knee revision surgery. METHOD Participating patients scheduled for hip and knee prosthetic revision were randomised into two groups: one receiving standard povidone-iodine gauze and patch wound dressing (control group) and the other NPWT over the sutured wound area (NPWT group). Patients were evaluated by means of ASEPSIS score, occurrence of blisters, visual analogue scale (VAS) and dressing changes seven days after surgery. We hypothesised a five-point difference in ASEPSIS scores as clinically relevant. RESULTS A total of 110 patients were enrolled in the study. Mean ASEPSIS score was 5.1 for the control group and 3.0 for the NPWT group, with a significant difference in the ASEPSIS score between groups (p<0.001), although this was not clinically relevant. Considering patients with more than three risk factors for healing complication, a statistical difference of >5 points ASEPSIS score was recorded (p<0.0005). Blister occurrence, VAS score and number of dressing changes were significantly lower in the NPWT group. CONCLUSION The results of this study do not support the routine use of NPWT after hip and knee revision. However, it could be beneficial for selected patients once specific risk factors for wound healing complications have been determined.

Functional evaluation of bilateral subtalar arthroereisis for the correction of flexible flatfoot in children: 1-year follow-up

BACKGROUND Flexible flatfoot (FFF) is a common alteration of the foot diagnosed in the pediatric population causing pain and decreased quality of life. Surgical treatment via arthroereisis of the subtalar joint can be recommended when non-invasive options do not result in sufficient pain relief. While clinical outcome of subtalar joint arthroereisis is generally positive, no functional evaluation has thus far been reported following surgery. RESEARCH QUESTION The aim of this study was to assess the effects of two arthroereisis implants for the correction of bilateral FFF on foot and lower limb biomechanics during gait. METHODS This is a prospective study following 13 children affected by bilateral symptomatic FFF. The patients underwent bilateral subtalar arthroereisis during the same surgery using two types of poly-L-lactide bioabsorbable implants: an expanding endo-orthotic implant, and a calcaneo-stop screw. Radiological parameters and gait analysis were performed preoperatively and at 1 year follow-up and compared to those from an age-matched normal-arched control population. Lower limb and multisegment foot kinematic analysis, along with EMG of the main ankle flexor/extensor muscles, were performed during level walking at comfortable speed. Paired non-parametric Wilcoxon signed-rank test was used to assess differences in radiological and kinematic parameters between pre-op and post-op assessments. RESULTS All radiological parameters, and frontal-plane orientation of the rearfoot in double-leg standing were improved at 1-year follow-up in both implant groups (e.g calcaneo-stop: pre-op = 15 ± 7 deg; post-op = 6 ± 9 deg; p < 0.01). The endo-orthotic implant group showed significantly lower pronation/supination at the ankle and midtarsal joint. Activation of the tibialis anterior muscle was more physiological after surgery in both groups. SIGNIFICANCE According to the present analysis, both implants appear effective in restoring physiological alignment of the rearfoot, however the endo-orthotic implant appeared more effective in restoring a more correct frontal-plane mobility of foot joints.

Two-stage surgical treatment for septic non-union of the forearm

AIM To investigate the effectiveness of a two-stage surgical procedure for the treatment of septic forearm non-union. METHODS Septic non-unions are rare complications of forearm fractures. When they occur, they modify the relationship between forearm bones leading to a severe functional impairment. Treatment is challenging and surgery and antibiotic therapy are required to achieve infection resolution. It is even harder to obtain non-union healing with good functional results. The aim of this study is to present a two stages surgical treatment for septic forearm non-union with revision and temporary stabilization of the non-union until infection has cleared and subsequently perform a new synthesis with plate, opposite bone graft strut and intercalary graft. We retrospectively reviewed 18 patients with a mean age at the time of primary injury of 34.5 years (19-57 years) and a mean follow-up of 6 years (2-10 years). All patients presented an atrophic non-union with a mean length of the bone defect of 1.8 cm (1.2-4 cm). Complications and clinical results after surgical treatment were recorded. RESULTS Mean time to resolution of the infectious process was 8.2 wk (range 4-20 wk) after the first surgery and specific antibiotic therapy. All the non-union healed with an average time of 5 mo (range 2-10 mo) after the second step surgery. Cultures on intraoperative samples were positive in all cases. No major intraoperative complications occurred. Two patients developed minor complications and one needed a second surgical debridement for infection resolution. At the last follow-up functional results were excellent in 5 (27.8%) patients, satisfactory in 10 (55.5%) and unsatisfactory in 3 (16.7%) patients. No activities of daily living (ADLs) limitations were reported by 12 (66.6%) patients, slight by 3 (16.6%) and severe limitation by 3 (16.6%) patients. Mean visual analog scale at the last follow-up was 1 (0-3). CONCLUSION The two-step technique has proven to be effective to achieve resolution of the infectious process and union with good functional results and low rate of complications.