Introduction. Despite the rising popularity of 1st carpometacarpal joint (CMCJ) arthrodesis as one of the surgical options for basilar thumb arthritis, the available literature on this is poor. This study aims to investigate post-operative pinch and grip strength following 1st CMCJ arthrodesis, at a minimum of 1 year follow-up. Complication rates, range of motion and patient reported scores were also evaluated. Methods. A retrospective cohort (2012–2020) was used, which included patients who had arthrodesis performed by the Hands surgeons at Counties Manukau DHB. In a 15 minute visit, we took the measurements using our standard dynamometer and pinch gauge, and collected three questionnaires [QuickDASH, PRWHE, PEM]. For analysis, we compared our results to the preoperative measures, contralateral hand, and to a previous study on a similar cohort looking at thumb strength following trapeziectomy. Results. 42 arthrodesis were performed, and 24 were available for follow-up. The average follow-up time was 77 months and the average age was 51 years old. Overall, we found a statistically significant improvement in thumb strength following surgery. Mean preoperative grip strength was 21.4kg and 32.5kg postoperatively (= +11kg). Preoperative pinch strength was 5.5kg and 7kg postoperatively (= +1.5kg). These results were significantly higher compared to the trapeziectomy cohort. We also found an improvement in 1st CMCJ ROM post-operatively. 7 complications were reported (29.1%). 4 were metalware-related and 3 were non-union. QuickDASH score significantly improved from a median of 42.95 to 12.5 while PRWHE from 67.5 to 14.5. Overall patient satisfaction was 87.4%. Conclusion. 1st CMCJ arthrodesis leads to an improvement in thumb function, pain and range of movement and results in high patient satisfaction, and therefore should be recommended for younger patients who need a pain-free and strong thumb

Shoulder arthroplasty procedures continue to increase in prevalence and controversy still remains about the optimal method to manage the subscapularis. Scalise et al. performed an analysis of 20 osteotomies and 15 tenotomy procedures, and found the tenotomy group had a higher rate of abnormal subscapularis tendons on ultrasound examination. There was one tendon rupture in the subscapularis tenotomy group and no ruptures in the osteotomy group. Jandhyala et al. retrospectively examined 26 lesser tuberosity osteotomies and 10 subscapularis tenotomies for arthroplasty, and their study demonstrated a significant improvement in the belly press test for the osteotomy group. Lapner et al. performed a randomised controlled trial assigning patients to either a lesser tuberosity osteotomy or a subscapularis peel procedure. They evaluated 36 osteotomies and 37 subscapularis peels. The outcomes evaluated were Dynamometer internal rotation strength, the Western Ontario Osteoarthritis of the Shoulder Index (WOOS) score and American Shoulder and Elbow Surgeons (ASES) score, and in a subsequent paper they evaluated the healing rates and Goutallier grade. Their studies illustrated no difference in the internal rotation strength between groups. Both groups significantly improved WOOS and ASES scores postoperatively, but the difference was not significant between groups. Goutallier grade increased significantly in both groups, but there was no significant difference between the groups. Overall, the different approaches have not demonstrated a meaningful clinical difference. Further studies are needed to help understand issues leading to subscapularis complications after arthroplasty

Background. Revision total knee arthroplasties (rTKA) are performed with increasing frequency due to the increasing numbers of primary arthroplasties, but very little is known regarding the influence of muscle strength impairments on functional limitations in this population. Objectives. The aim of this study was to assess relationship between muscle strength and functional level in patient with rTKA. Design and Methods. Twenty-three patients (8 males, 15 females) were included in the study with mean age 68.4±10 years. Patients performed 3 performance tests (50-Step Walking Test, 10 Meter Walk Test, 30-Second Chair-Stand Test), and one self-report test (HSS) were preferred to assess patients. The maximum isometric muscle strength of quadriceps femoris and hamstring muscles of all the patients was measured using Hand-Held Dynamometer (HHD). Results. While moderate-to-strong significant correlations was found between quadriceps femoris muscle strength and 30- Second Chair-Stand Test (r=0.390, p=0.049), 50-Step Walking Test (r=−0.530, p=0.005), 10 Meter Walk Test (r=−0.587, p=0.002), there were not significant correlation between HSS knee score and all performance-based tests (p>0.05). Also there were not significant correlation between hamstring muscle strength and all other measurement tests (p>0.05). Conclusion. The moderate-to-strong statistical significant correlation between quadriceps femoris muscle strength and functional performance tests suggests that improved postoperative quadriceps strengthening could be important to enhance the potential benefits of rTKA

Introduction. Most of patients with unilateral hip disease shows muscle volume atrophy of pelvis and thigh in the affected side because of pain and disuse, resulting in reduced muscle weakness and limping. However, it is unclear how the muscle atrophy correlated with muscle strength in the patient with hip disorders. A previous study have demonstrated that the volume of the gluteus medius correlated with the muscle strength by volumetric measurement using 3 dimensional computed tomography (3D-CT) data, however, muscles influence each other during motions and there is no reports focusing on the relationship between some major muscles of pelvis and thigh including gluteus maximus, gluteus medius, iliopsoas and quadriceps and muscle strength in several hip and knee motions. Therefore, the purpose of the present study is to evaluate the relationship between muscle volumetric atrophy of major muscles of pelvis and thigh and muscle strength in flexion, extension and abduction of hip joints and extension of knee joint before surgery in patients with unilateral hip disease. Material and Methods. The subjects were 38 patients with unilateral hip osteoarthritis, who underwent hip joint surgery. They all underwent preoperative computed tomography (CT) for preoperative planning. There were 6 males and 32 females with average age 59.5 years old. Before surgery, isometric muscle strength in hip flexion, hip extension, hip abduction and knee extension were measured using a hand held dynamometer (µTas F-1, ANIMA Japan). Major muscles including gluteus maximus, gluteus medius, iliopsoas and quadriceps were automatically extracted from the preoperative CT using convolutional neural networks (CNN) and were corrected manually by the experienced surgeon. The muscle volumetric atrophy ratio was defined as the ratio of muscle volume of the affected side to that of the unaffected side. The muscle weakness ratio was defined as the ratio of muscle strength of the affected side to that of the unaffected side. The correlation coefficient between the muscle atrophy ratio and the muscle weakness ratio of each muscle were calculated. Results. The average muscle atrophy ratio was 84.5% (63.5%–108.2%) in gluteus maximus, 86.6% (65.5%–112.1%) in gluteus medius, 81.0% (22.1%–130.8%) in psoas major, and 91.0% (63.8%–127.0%) in quadriceps. The average muscle strength ratio was 71.5% (0%–137.5%) in hip flexion, 88.1% (18.8%–169.6%) in hip abduction, 78.6% (21.9%–130.1%) in hip extension and 84.3% (13.1%–122.8%) in knee extension. The correlation coefficient between the muscle atrophy and the ratio of each muscle strength between the affected and unaffected side were shown in Table 1. Conclusion. In conclusion, the muscle atrophy of gluteus medius muscle, psoas major muscle and quadriceps muscle significantly correlated with the muscle weakness in hip flexion. The muscle atrophy of psoas major muscle and quadriceps muscle also significantly correlated with the muscle weakness in knee extension. There were no significant correlation between the muscle atrophy and the muscle weakness in hip extension and abduction

Purpose. Investigating the effects of femoral stem length on hip and knee muscle strength. Methods. The study included 20 patients having undergone total knee prostheses (TKP) due to coxarthrosis and 10 healthy subjects. Of the 20 patients, 10 underwent conventional TKP and 10 had Thrust Plate Prothesis (TPP). For the assessment of the patients’ muscle strength of operated and non-operated hips (Gl. medius and Gl. Maximus) and knees (Quadriceps Femoris-QF), the Hand-Held Dynamometer (HHD) was used. Results. A significant difference was observed in the muscle strength of Gl. medius in TPP patients and of Gl. maksimus in conventional TKP patients (p <0.05). Compared to the healthy group, only hip muscle strength decreased in TPP patients, but both hip and knee muscle strengths decreased in conventional TKP patients (p <0.05). Conclusion. A decrease in hip and knee muscle strengths was determined in the TPP and conventional THA patients, compared to healthy subjects. Compared to the bone protective prosthetic systems (eg TPP), a significant difference is observed in the QF muscle strength in intramedullary prosthesis applications. This data may be used in planning the treatment of patients with hip arthroplasty

Introduction. The role of soft tissue balancing in optimising functional outcome and patient satisfaction after total knee arthroplasty surgery is gaining interest. Consistent soft tissue balancing has been aided by novel technologies that can quantify loads across the joint at the time of surgery. Based on free body diagram theory, compressive load equilibrium should be correlated with ligamentous equilibrium between the medial and lateral collateral ligaments. The authors propose to use the Collateral Ligaments Strain Ratio (CLSR) as a functional tool to quantify and track the effectuated surgical change in laxity of the medial and lateral collateral ligaments and correlate this ratio to validated functional scores and patient reported outcomes. The relationship with intra-operative balancing of compartmental loads can then be scrutinised. Methods. The study is a prospective clinical study with three cohorts of 50 patients each: (1) a surgical prospective study group with ligamentous testing pre-operatively, at 4 weeks, 3 months and 6 months post-operatively; (2) a matched control group of non-operated high function patients; (3) a matched control group of high function knee arthroplasty recipients. Standard statistical analysis method is applied. The testing of the CLSR is performed using a validated Smart Knee Brace developed by the authors and previously reported. The output variables consist of the maximum angular change of the knee in the coronal plane at 10 degrees of flexion produced by a controlled torque application in the varus and valgus (VV) directions. This creates measureable strain on the lateral and medial collateral ligaments, which is reported as a ratio (CLSR). The New Knee Society Score is used to track outcomes. The intra-operative balance is achieved by means of an instrumented tibial tray (OrthoSensor, Inc). The applied torque was standardised to 10Nm with a handheld wireless dynamometer. Results. Pre-operative scatter graphs demonstrate a wide distribution of absolute VV values, reflecting the spectrum of pathological states. The relative distribution of strain after surgery trends towards consolidation. The median CLSR is 0.55 with a SD of 0.20. This asymmetrical value indicates a shift toward a tighter medial side. The overall displacement values range from 0–4 degrees. The angular changes under standard torque appear to correlate with the linear displacement values previously reported by Bellemans et al

Shoulder arthroplasty procedures continue to increase in prevalence, and controversy still remains about the optimal method to manage the subscapularis. Scalise et al. performed an analysis of 20 osteotomies and 15 tenotomy procedures, and found the tenotomy group had a higher rate of abnormal subscapularis tendons on ultrasound examination. There was one tendon rupture in the subscapularis tenotomy group and no ruptures in the osteotomy group. Jandhyala et al. retrospectively examined 26 lesser tuberosity osteotomies and 10 subscapularis tenotomies for arthroplasty, and their study demonstrated a significant improvement in the belly press test for the osteotomy group. Lapner et al. performed a randomised controlled trial assigning patient to either a lesser tuberosity osteotomy or a subscapularis peel procedure. They evaluated 36 osteotomies and 37 subscapularis peels. The outcomes evaluated were Dynamometer internal rotation strength, the Western Ontario Osteoarthritis of the Shoulder Index (WOOS) score and American Shoulder and Elbow Surgeons (ASES) score, and in a subsequent paper they evaluated the healing rates and Goutallier grade. Their studies illustrated no difference in the internal rotation strength between groups. Both groups significantly improved WOOS and ASES scores post-operatively, but the difference was not significant between groups. Goutallier grade increased significantly in both groups, but there was no significant difference between the groups. Overall, the different approaches have not demonstrated a meaningful clinical difference. Further studies are needed to help understand issues leading to subscapularis complications after arthroplasty

Introduction. Evaluation of post-operative soft tissue balancing outcomes after Total Knee Arthroplasty (TKA) and other procedures can be measured by stability tests, with Anterior-Posterior (AP) drawer tests and Varus-Valgus (VV) ligamentous laxity tests being particularly important. AP stability can be quantified using a KT1000 device; however there is no standard way of measuring VV stability. The VV test relies on subjective force application and perception of laxity. Therefore we sought to develop and validate a device and method for quantifying knee balancing by analyzing VV stability. Materials and Methods. Our team developed a Smart Knee Fixture to measure VV angular changes using two dielectric elastomer stretch sensors, placed strategically over the medial and lateral collateral ligaments (see Figure 1). The brace is secured in position with the leg in full extension and the sensors locked with pre-tension. Therefore, contraction and elongation of either sensor is measured and the VV angular deviation of the long axis of the femur relative to that of the tibia is derived and displayed in real time using custom software. EMG muscle activity was previously investigated to confirm there is no resistive activity during the VV test obstructing ligamentous evaluations. The device was validated in two ways:. A bilateral lower body cadaver specimen, secured in a custom test rig, was used to compare the Smart Knee Fixture's readings to those measured from an optical surgical navigation system. Abduction and adduction force was gradually applied as varus and valgus moments with a wireless hand-held dynamometer up to 50N (19.8Nm) at 0 and 15° flexion. Two male volunteers were used to compare the Smart Knee Fixture's readings to those measured from fluoroscopic images. An arthroscopic distal thigh leg immobilizer was used to prevent rotation and lateral movements of the thigh when moments were applied at the malleoli. A C-arm Fluoroscope was then positioned focusing on the center of the joint. The tests were performed at full extension, 10 and 20° of flexion and force was gradually applied to 50N. Results and Discussion. R values were calculated to validate the Smart Knee Fixture's accuracy. Excellent correlation was observed between the Smart Knee Fixture and the gold standard of navigation (see Figure 2). The R values were 0.9909 and 0.9966. Correlation was also observed between Smart Knee Fixture and the measured fluoroscopic angular changes. The R values were 0.9118 and 0.7529. Conclusions. The strong R values allow us to conclude that the Smart Knee Fixture can potentially be used to accurately measure VV angular changes in a clinical setting and hence provide a quantified measure of coronal plane soft tissue balance. Clinical studies are underway to compare TKA patient outcomes to balancing measured by the Smart Knee Fixture. This information should further define balancing goals at the time of surgery. We also envisage broader applications to early detection of ligamentous injury associated with sporting activities, such as multiple ligamentous knee injuries in teenage females

Soft tissue balancing in total knee replacement may well be the determining factor in raising the fair patient satisfaction. The development of intelligent implants allows quantification of reactive loads to applied pressures. This can be tested in dynamic mode such as heel push test at surgery, or in static mode such as when testing for varus/valgus (VV) laxity of the collateral ligaments of the knee. We postulate that a well-balanced knee will have comparable if not equal load distribution across compartments in dynamic loading. When tested for laxity, we anticipate an equal or comparable response to VV applied loads under physiologic load range of 10–50N. This study sought to analyze the relationship between the kinematic (joint motion) and kinetic (force) effects to VV testing in the 0–15 degrees range of flexion. One goal was to demonstrate that testing the knee in locked extension (Screw Home effect) is unreliable and should be abandoned in favor of the more reliable VV testing at 10–15 degrees of flexion. This is a preliminary cadaveric study utilizing data from two hemibodies. The pelvis was fixed in a custom test rig with open or closed chain lower leg testing capability along a sliding rail with foot VV translational. Forces were applied at the malleoli with a wireless hand held dynamometer. Kinematic analysis of the hip-knee-ankle (HKA) tibiofemoral angle was derived from a commercial navigation system with mounted infrared trackers. Kinetic analysis was derived from a commercially available sensor imbedded in a tibial trial liner. Balance was optimized by conventional methods with the use of the sensor feedback until loads were roughly symmetrical and VV testing yielded symmetrical rise in opposite compartments. The VV testing was then performed with the knees locked at the femoral side in axial rotation and translational motion in any plane. Sagittal flexion was pre-set at 0, 10, and 15 degrees and progressive load was applied. Results. From the graphs one can observe significant differences between VV testing at 0 degrees (locked Screw Home), 10 degrees, and 15 degrees of flexion. The shaded area corresponds to the common range of VV stress testing loading pressure, typically less than 35N. The HKA deviates from neutrality no sooner than by the middle of the physiologic test zone. By 35N, the magnitude of the effect is also much less than that observed at 10 and 15 degrees (unlocked from Screw Home). From the kinetic analysis one can also note the significant difference in the High-Low spread throughout the testing range of applied pressure. If the surgeon tests in the low range of applied loads, he/she may not observe the kinematic joint opening effect. The kinetic effect seems more reliable as sensed loads are detectable earlier on. It is clear however that testing at 10–15 degrees offers a much better sensitivity to the VV laxity or stiffness as exemplified in the bottom portions of the figure. Therefore testing in locked Screw Home full extension may lead to underestimation of the true coronal laxity of the joint

An anaesthetist recently remarked that orthopaedic surgeons are ‘twice as strong as an ox but half as smart’. We set out to ascertain if this had any evidence basis by conducting an observational study. We compared 36 male orthopaedic surgeons to 40 male anaesthetists across 3 hospitals to ascertain if there was a significant difference between the two groups in terms of Intelligence Quotient (IQ) and strength. We tested the IQ of each doctor using an official MENSA IQ test. We assessed the strength as reflected by the grip strength using a hand-grip dynamometer. Un-paired t-tests were used to assess statistical significance. Orthopaedic surgeons had a significantly greater mean grip strength 47.25Kg (SD=6.95) compared to anaesthetists 43.83Kg (SD=7.57) (p=0.04). The mean IQ of orthopaedic surgeons was also significantly greater at 105.19 (SD=10.85) than anaesthetists at 98.38 (SD=14.45) (p=0.02). Furthermore, the IQ of orthopaedic surgeons seems to increase with increasing age and seniority (an IQ jump of 5 IQ points from Registrar to Consultant). We have concluded that this proverb should be revised to orthopaedic surgeons are as strong as an ox and twice as smart, although further studies are advocated to ascertain the IQ of Ox

Purpose of Study. Lengthening of the gastrocsoleus for equinus deformity is commonly performed in orthopaedic surgery. The aim of this study was to describe the precise details of each surgical procedure and assess each biomechanically in cadaver models. Description of Methods. The surgical anatomy of the gastrocsoleus was investigated and standardized approaches were developed for the procedures described by Baumann, Strayer, Vulpius, Baker, Hoke and White. The biomechanical characteristics of these six procedures were then compared, in three randomized trials, in formalin preserved, human cadaver legs. The lengthening procedures were performed and a measured dorsiflexion force was applied across the metatarsal heads using a torque dynamometer. Lengthening of the gastrocsoleus was measured directly, by measuring the gap between the ends of the fascia or tendon. Summary of Results. The gastrocsoleus muscle-tendon-unit was divided into three zones. In Zone 1, it was possible to lengthen the gastrocnemius alone or to lengthen the gastrocnemius and soleus by different amounts. These procedures (Baumann, Strayer) were very stable but limited in the amount of lengthening achieved. Zone 2 lengthenings (Vulpius, Baker) of the conjoined gastrocnemius aponeurosis and soleus fascia were not selective but were stable and resulted in significantly greater lengthening than Zone 1 (p < 0.001) 4. Conclusion. Surgery for equinus deformity correction by lengthening of the gastrocsoleus varies in terms of selectivity, stability and range of correction with differing anatomical and biomechanical characteristics. Clinical trials are needed to determine whether these differences are of clinical importance. It may be appropriate for surgeons to select a procedure from a zone, best suited to the clinical needs of a specific patient. NO DISCLOSURES

Conventional computer navigation systems using bone fixation have been validated in measuring anteroposterior (AP) translation of the tibia. Recent developments in non-invasive skin-mounted systems may allow quantification of AP laxity in the out-patient setting. We tested cadaveric lower limbs (n=12) with a commercial image free navigation system using passive trackers secured by bone screws. We then tested a non-invasive fabric-strap system. The lower limb was secured at 10° intervals from 0° to 60° knee flexion and 100N of force applied perpendicular to the tibial tuberosity using a secured dynamometer. Repeatability coefficient was calculated both to reflect precision within each system, and demonstrate agreement between the two systems at each flexion interval. An acceptable repeatability coefficient of ≤3mm was set based on diagnostic criteria for ACL insufficiency when using other mechanical devices to measure AP tibial translation. Precision within the individual invasive and non-invasive systems measuring AP translation of the tibia was acceptable throughout the range of flexion tested (repeatability coefficient ≤1.6mm). Agreement between the two systems was acceptable when measuring AP laxity between full extension and 40° knee flexion (repeatability coefficient ≤2.1mm). Beyond 40° of flexion, agreement between the systems was unacceptable (repeatability coefficient >3mm). These results indicate that from full knee extension to 40° flexion, non-invasive navigation-based quantification of AP tibial translation is as accurate as the standard invasive system, particularly in the clinically and functionally important range of 20° to 30° knee flexion. This could be useful in diagnosis and post-operative follow-up of ACL pathology

Purpose. Controversy exists regarding the optimal technique of subscapularis mobilization during shoulder arthroplasty. The purpose of this multicentre randomized double-blind study was to compare the functional outcomes and healing rates of the lesser tuberosity osteotomy (LTO) to the subscapularis tenotomy (ST). Method. Patients undergoing shoulder arthroplasty were randomized to receive either a LTO or ST. The primary outcome was to compare subscapularis strength, as measured by an electronic hand-held dynamometer at 12 months. Secondary outcomes included range of motion, WOOS, Constant and ASES scores. A sample size calculation determined that 80 patients provided 80% power with a 50% effect size to detect a significant difference between groups. Results. Baseline demographic data did not differ between groups including age (p=0.69), sex (p=0.77), affected side (p=0.59) and arthroplasty type (hemiarthroplasty or total, p=0.77). Strength comparison between groups revealed no statistical differences at any time interval (p=0.744, baseline, p=0.449, 3 month, p=0.203, 6 months, 12 months, p=0.45). Statistically significant improvements occurred in both groups from baseline to 12 month time points in all clinical outcome scores (p<0.0001). Conclusion. No statistically significant differences in primary or secondary outcomes were identified between the LTO and ST. This trial does not demonstrate any clear advantage of one subscapularis mobilization technique over the other

Purpose. The Purpose of this study was to evaluate hamstring strength after autogenous hamstring anterior cruciate ligament(ACL) reconstruction with emphasis on deeper knee flexion angles. A comparison of hamstring strength between patients undergoing ACL reconstruction using semitendinosus(ST), and those with semitendinosus and Gracilis(STG) tendons was conducted. Method. Sixty patients were prospectively followed after undergoing ACL reconstruction surgery. Forty patients received a ST graft, and 20 patients had a STG graft. All patients had standard IKDC subjective knee evaluation completed, and had bilateral hamstring strengths tested using isokinetic testing with a Cybex Orthotron machine. In addition, a hand held Microfet dynamometer was used to measure hamstring strengths at deeper knee flexion angles at six, 12, and 24 months. Results. When comparing the surgical hamstring strength compared to the control side at deeper knee flexion angle, the STG and ST group had and average of 65.0% and 79.8% strength respectively at 6 months(p<0.05). While at one year the STG and ST group had 63.6%, and 78.3% of their hamstring strength(p<0.05). Conclusion. Hamstring strength at deeper flexion angles after ACL reconstruction using autogenous semitendinosus and gracilis tendons is significantly weaker than using semitendinosus alone. The use of single tendon ACL reconstruction should be advocated to decrease morbidity of this procedure

Introduction. The purpose of this study was to determine whether the patient's perceived outcome and speed of recovery differs between a posterior cruciate ligament (PCL) substituting (cam-post type) and PCL sacrificing (ultracongruent polyethylene) total knee arthroplasty (TKA). Methods. Thirty eight patients (mean age, 65 years) underwent bilateral TKA using a PCL substituting and a PCL sacrificing prosthesis on each side. At each follow-up, the stability of anteroposterior and mediolateral laxity using stress radiographs, range of motion, quadriceps muscle power recovery using isokinetic dynamometer and radiographs were evaluated. At the 1-year evaluation, we asked, “Which is your better knee overall?” to determine the patients' preferences. Results. The mean varus/valgus laxities were 1.6Ë�/3.9Ë� in the PCL sacrificing side and 2.3Ë�/5.9Ë� in the PCL substituting side, and the mean anterior/posterior laxities were 6.4 mm/14.2 mm and 3.0 mm/7.3 mm at the 1-year follow up, respectively. Isokinetic peak torque at 60°/sec and 180°/sec in extension was 130% and 113% compared to the preoperative value in the PCL sacrificing side and 109% and 110% in the PCL substituting side, respectively. The differences in the posterior laxity and isokinetic peak torque at 60°/sec were significant statistically. Sixty-one percent preferred PCL sacrificing side to PCL substituting side. Conclusion. PCL sacrificing TKA showed more posterior laxity and better quadriceps muscle power at the time of short-term follow-up. Patients with bilateral TKA preferred PCL sacrificing TKA to PCL substituting TKA. Longer follow-up is needed to determine whether there will be an advantage in terms of longer-term function

Introduction:. Gait analysis is an important tool to measure function following total knee replacement. It is currently unknown whether there is a correlation between subjective and objective outcome. The purpose of this study was to analyse relationships between subjective outcome scores and kinematic and kinetic data. Methods:. 25 consecutive patients (15 males, 10 females) were selected (mean age 68 years, BMI 31.8). All subjects were tested a minimum of 24 months following total knee replacement. SF12, Oxford knee score, knee society and KOOS scores were collected. Muscle strength was assessed using a Biodex dynamometer and symmetry indices were analysed. A timed up and go test and KT2000 measurements were performed. Results:. Strong correlations (r=0.52–0.74) were found between scoring systems (SF 12, Oxford knee score, knee society score, KOOS score) and the timed up and go test. Moderate correlations (r=0.27–0.35) were found between knee scores and KT2000 measurements. Only weak correlations (r=0.09–0.12) were found between knee scores and strength. None of the correlations reached statistical significance. Post hoc contrasts demonstrated adequate power (0.95) of the study. Conclusion:. The finding of this study suggests that outcome scores and objective and functional tests following total knee arthroplasty measure different variables of outcome. Whilst objective tests and gait analysis provide an understanding of joint mechanics after surgery and can be used to calculate resultant forces and moments, patient perceived outcomes have no significant correlation to knee biomechanics. This may be related to factors such as pain relief, improved quality of life and the ability to perform activities of daily life. In contrast modern implants may provide a satisfactory outcome resulting in high patient satisfaction. The results of this study underline the importance of using subjective patient outcome measures

INTRODUCTION. Cadaveric studies have reported damage to the direct head of rectus femoris and tensor fascia lata muscles with direct anterior approach(DAA) and to the abductors, external rotators with posterior approach(PA). The aim of this prospective study was to evaluate differences in hip muscle strength recovery between DAA and posterior approach (PA) THA. METHODS. Patients with unilateral hip osteoarthritis undergoing THA at a single institution from January 2011 to October 2011 were enrolled. All DAA THA's were performed by one surgeon, and all PA THA's were performed by another surgeon with similar design of components, pain management and rehabilitation protocols. Hip muscle strength was measured with a handheld dynamometer in all planes by a single observer preoperatively, at 6 weeks, 3 months and 6 months. Functional recovery was assessed with the motor component of Functional Independence Measure, UCLA activity score, Harris hip score, SF-12 score. RESULTS. There were 30 patients (15 per group) with similar age, sex, BMI and preoperative functional scores. There was a significant difference between groups in ER strength recovery pattern(p=0.04) with greater mean deficit in PA group from preoperative to 6 weeks(37%), 3 months (28%) and 6 months (25%); whereas DAA group demonstrated 3% mean deficit at 6 weeks, 2% mean improvement at 3 months and 10% mean improvement at 6 months from preoperative values. Flexion strength decreased in DAA group by a mean of 10% at 6 weeks(p=0.07) but improved at 3 months by a mean of 12% as compared to preoperative values. There were no differences in recovery pattern of other hip movements between groups. Functional recovery scores between groups were similar. DISCUSSION. Both DAA and PA THA offer similar recovery in hip muscle strength up to 6 months with exceptions of ER strength deficit in PA group and a trend to flexion strength deficit at 6 weeks in DAA group

Purpose. Handgrip dynamometry has previously been used to detect pre - operative malnutrition and predict the likelihood of post - operative complications. This study explored whether a relationship exists between pre-operative pinch and power grip strength and length of hospital stay in patients undergoing hip and knee arthroplasty. We investigated whether handgrip dynamometry could be used pre - operatively to identify patients at greater risk of longer inpatient stays. Methods. 164 patients (64 male, 100 female) due to undergo lower limb arthroplasty (83 Total Knee Replacement, 81 Total Hip Replacement) were assessed in pre - admission clinic. Average measurements of pinch grip and power grip were taken from each patient using the Jamar hydraulic dynamometer (Jamar, USA). Duration of each inpatient stay was recorded. Patients with painful or disabling conditions involving the upper limb were excluded. Other clinical variables such as age and ASA grade were investigated as potential confounders of the relationship of interest and adjusted for. Results. Average duration of hospital stay was 9.4 days. Average pinch grip was 6.3kg, average power grip 25.4 kg. Both average pinch grip strength (p = 0.001) and average power grip strength (p=0.04) had a significant negative correlation with duration of inpatient stay. Patients with a pinch grip strength less than 6.3kg remained in hospital 2 days longer on average. Patients with a power grip strength less than 15kg remained in hospital 1.6 days longer on average. Conclusions. This study demonstrated a clear relationship between pre - operative grip strength and length of hospital admission in these patients. This simple test may be beneficial pre - operatively in identifying those patients likely to require longer inpatient stays and therefore those who would benefit from early nutritional intervention and focussed physiotherapy. We believe this may effect significant cost reductions in the NHS

Purpose. Whether the presence of knee effusion in individuals with knee osteoarthritis (OA) affects periarticular neuromuscular control during gait and thus the joint loading environment is unknown. The purpose was to test the hypothesis that knee effusion presence alters periarticular neuromuscular patterns during gait in individuals with moderate knee OA. Method. 40 patients with medial compartment knee OA participated after giving informed consent. Patients were assessed for the presence of effusion using a brush test and were assigned to the knee effusion (n=20) and no knee effusion (n=20) groups. Surface electrodes were placed in a bipolar configuration over the lateral and medial gastrocnemius, vastus lateralis and medialis, rectus femoris and the lateral and medial hamstrings of the affected limb. Five trials of self-selected walking were completed. Electromyograms (EMG) were collected using an AMT-8 EMG system (Bortec Inc.). An Optotrak motion capture system (Northern Digital Inc.) recorded leg motion. Euler rotations were used to derive knee angles. EMG waveforms were low-pass filtered and amplitude normalized to maximal effort voluntary isometric contractions. Quadriceps, gastrocnemius and hamstring strength was measured from torques produced against a Cybex dynamometer. Principal Component Analysis extracted the predominant waveform features and weighting scores were calculated for each measured waveform. Analysis of variance models test for main effects (group, muscle) and interactions (alpha = 0.05). Bonferonni post hoc testing was employed. Results. No differences in age, body mass index, knee pain, Western Ontario McMaster Osteoarthritis Index scores, gait velocity and muscle strength were found between groups (p>0.05). Gastrocnemius activation was not influenced by the presence of effusion (p>0.05). For individuals with effusion, a greater overall quadriceps activation was found and a prolonged hamstring activation into mid-stance only (p<0.05). Range of motion excursion from heel strike to peak extension during terminal stance was greater with effusion (p<0.05). Conclusion. The hypothesis that knee effusion in those with moderate knee OA is associated with alterations in quadricep and hamstring muscle activation patterns and sagittal plane knee motion during gait was supported. Quadriceps muscle inhibition during the normalization exercises may provide a partial explanation, consistent with results from acute effusion models. However, the hamstring alteration during mid-stance only, no strength differences between the two groups and altered kinematics support that mechanisms other than muscle inhibition are responsible for the altered patterns. These novel findings are a first step at understanding the effects of knee effusion on periarticular muscle function during gait that subsequently can affect the mechanical environment of the joint in those with a more chronic effusion

Purpose. Stress fractures (SFs) are highly prevalent in female athletes, especially runners (1337%), and result in pain and lost training time. There are numerous risk factors for SFs in athletes; however, the role of bone quality in the etiology of SFs is currently unknown. Therefore, our primary objective was to examine whether there are characteristic differences in bone quality and bone strength in female athletes with lower limb SFs using high-resolution peripheral quantitative computed tomography (HR-pQCT). A secondary objective was to compare muscle strength between SF subjects and controls. Method. Female athletes with (n=19) and without (n=19) lower limb SFs were recruited from the local community. All SFs were medically confirmed by a physician and subjects were assessed within 1–47 weeks (12.7 13.7) of diagnosis. Controls were age-, training volume- and sport-matched to SF athletes. Bone density and microarchitectural bone parameters such as cortical thickness and porosity, as well as trabecular thickness, separation and number of all subjects were assessed using HR-pQCT at two distal tibia scanning sites (distal, ultra-distal). Finite element (FE) analysis was employed to estimate bone strength and load sharing of cortical and trabecular bone from the HR-pQCT scans. Regional analysis was applied to the HR-pQCT scans to investigate site-specific bone differences between groups. Muscle torque was measured by a Biodex dynamometer as a surrogate of muscle strength. Independent sample t-tests and Mann-Whitney U-tests were used for statistical analyses (p < 0.05). Results. Significant differences and trends indicated compromised trabecular bone and slightly thicker cortices with fewer pores in SF subjects compared with controls. This was most pronounced in the posterior region of the distal tibia, which is the site of highest tensile stresses during running and a common SF site. FE analysis indicated significantly higher cortical loads (median 4.2% higher; p=0.03) in the distal tibia site (but not ultra-distal site) of SF subjects compared to controls. The SF group exhibited significantly reduced knee extension strength (median 18.3% lower; p=0.03) and a trend towards reduced plantarflexion (median 17.3% lower; p=0.24) and eversion strength (median 9.6% lower; p=0.49) compared to controls. Conclusion. This is the first study to compare bone microarchitectural quality and lower-limb muscle strength between female athletes with SFs and health controls. A reduced trabecular bone quality in SF subjects may result in an insufficient ability to absorb and distribute tibial loads. This, in turn, may lead to higher stresses in the cortex and a higher risk for SFs. Low muscle strength may increase SF risk by providing insufficient muscular support to counteract shear stresses associated with reaction forces during running. Further study is needed to determine whether a resistance-training program can improve bone quality and in turn, reduce SF risk