Amir Haim

Hip-spine Syndrome: The Effect of Total Hip Replacement Surgery on Low Back Pain in Severe Osteoarthritis of the Hip

Study Design. Prospective clinical study on the effect of total hip replacement surgery (THR) on low back pain (LBP) in patients with severe hip osteoarthritis. Objective. To assess the affect of THR on LBP. Summary of Background Data. Hip osteoarthritis causes abnormal gait and spinal sagittal alignment and is associated with LBP. Methods. All consecutive adults scheduled for THR in our department due to severe hip osteoarthritis were assessed by an independent investigator before surgery and 3 months and 2 years post-THR. The Harris Hip Score and the Oswestry scores were used to evaluate hip- and spine-related symptoms, respectively, as were visual analogue scales (VAS) and sagittal spinal radiographs. Results. Twenty-five patients (10 males; age range, 32–84 years) were evaluated. Both spinal and hip pain and function were significantly better following THR. The mean preoperative LBP VAS score of 5.04 was 3.68 after THR (P = 0.006). The mean preoperative Oswestry score of 36.72 was 24.08 after THR (P = 0.0011). Clinical improvement was maintained and enhanced at the 2-year follow-up. The mean hip pain VAS score was 7.08 before THR and 2.52 after THR (P < 0.01). The mean Harris Hip Score was 45.74 before and 81.8 after surgery (P < 0.01). There were no changes in the radiographic measurements. Conclusion. Both LBP and spinal function were improved following THR. This study demonstrates the clinical benefits of THR on back pain and is the first to clinically validate hip-spine syndrome as hypothesized by Offierski and MacNab in 1983.

Patellofemoral Pain Syndrome: Validity of Clinical and Radiological Features

Data regarding validity of clinical and radiographic findings in diagnosing patellofemoral pain syndrome are inconclusive. We prospectively assessed how sensitive and specific key patellofemoral physical examination tests are, and evaluated the prevalence of physical examination and radiographic findings. Sixty-one infantry soldiers with patellofemoral pain syndrome and 25 control subjects were evaluated. The sensitivity of the patellar tilt, active instability, patella alta, and apprehension tests was low (less than 50%); specificity ranged between 72% and 100%. Although the prevalence of positive patellar tilt and active instability tests was significantly greater in subjects with patellofemoral pain syndrome, there were no significant differences between the groups in the results of the other two tests. Soldiers with patellofemoral pain syndrome presented with increased quadriceps angle, lateral and medial retinacular tenderness, patellofemoral crepitation, squinting patella, and reduced mobility of the patella. There were no differences between the groups in the prevalence of lower limb and foot posture alignment and knee effusion. Plain radiography showed increased patellar subluxation in soldiers with patellofemoral pain syndrome. Other radiographic measures (sulcus angle, Laurin angle, Merchant angle, and Insall-Salvati index) were similar in both groups. We provide evidence regarding the validity of clinical and radiographic features commonly used for diagnosing patellofemoral pain syndrome. Physical examinations were more useful than plain radiography.Level of Evidence: Diagnostic study, Level I. See the Guidelines for Authors for a complete description of levels of evidence.

Acquired activated protein C resistance is common in cancer patients and is associated with venous thromboembolism

PURPOSE Cancer patients have an increased risk for venous thromboembolism. Because activated protein C resistance is a common risk factor for venous thromboembolism, we prospectively evaluated the activated protein C sensitivity ratio and factor V Leiden mutation in cancer patients with and without venous thromboembolism. SUBJECTS AND METHODS We studied 55 consecutive cancer patients with deep vein thrombosis, 58 cancer patients with no history of venous thromboembolism, 54 patients with venous thromboembolism without malignancy, and 56 healthy controls. The presence of factor V Leiden mutation was determined by polymerase chain reaction and allele specific restriction digestion. The activated protein C sensitivity ratio was expressed as the ratio of activated partial thromboplastin times measured in the presence and absence of activated protein C; a ratio <2.0 in patients who did not have factor V Leiden was considered to indicate acquired activated protein C resistance. RESULTS The prevalence of factor V Leiden mutation in cancer patients with thromboembolism (1 of 55, 2%) did not differ significantly from those in cancer patients without thromboembolism (4 of 58, 7%) or normal controls (2 of 56, 4%), but was significantly lower than that of patients with thromboembolism without cancer (18 of 54, 33%, P <0.001). The prevalence of acquired activated protein C resistance was significantly greater in cancer patients with thromboembolism (29 of 54, 54%, P = 0.001) compared with the other groups: 9 of 54 (17%) in cancer patients without thromboembolism, 7 of 36 (19%) in patients with thromboembolism without cancer, and none of the normal controls. CONCLUSION Although factor V Leiden is not a major risk factor for thrombosis in cancer patients, acquired activated protein C resistance is common and may contribute to the thrombotic tendency in these patients.

The effect of clopidogrel and aspirin on blood loss in hip fracture surgery

INTRODUCTION Anti-platelet drugs are commonly used for primary and secondary prevention of thrombo-embolic events and following invasive coronary interventions. Their effect on surgery-related blood loss and perioperative complications is unclear, and the management of trauma patients treated by anti-platelets is controversial. The anti-platelet effect is over in nearly 10 days. Notably, delay of surgical intervention for hip fracture repair for >48 h has been reported to increase perioperative complications and mortality. PATIENTS AND METHODS Intra-operative and perioperative blood loss, the amount of transfused blood and surgery-related complications of 44 patients on uninterrupted clopidogrel treatment were compared with 44 matched controls not on clopidogrel (either on aspirin alone or not on any anti-platelets). RESULTS The mean perioperative blood loss was 899±496 ml for patients not on clopidogrel, 1091±654 ml for patients on clopidogrel (p=0.005) and 1312±686 ml for those on combined clopidogrel and aspirin (p=0.0003 vs. all others). Increased blood loss was also associated with a shorter time to operation (p=0.0012) and prolonged surgical time (p=0.0002). There were no cases of mortality in the early postoperative period. CONCLUSIONS Patients receiving anti-platelet drugs can safely undergo hip fracture surgery without delay, regardless of greater perioperative blood loss and possible thrombo-embolic/postoperative bleeding events.

Control of knee coronal plane moment via modulation of center of pressure: A prospective gait analysis study

OBJECTIVES Footwear-generated biomechanical manipulations (e.g., wedge insoles) have been shown to reduce the magnitude of adduction moment about the knee. The theory behind wedged insoles is that a more laterally shifted location of the center of pressure reduces the distance between the ground reaction force and the center of the knee joint, thereby reducing adduction moment during gait. However, the relationship between the center of pressure and the knee adduction moment has not been studied previously. The aim of this study was to examine the association between the location of the center of pressure and the relative magnitude of the knee adduction moment during gait in healthy men. METHODS A novel foot-worn biomechanical device which allows controlled manipulation of the center of pressure location was utilized. Twelve healthy men underwent successive gait analysis testing in a controlled setting and with the device set to convey three different para-sagittal locations of the center of pressure: neutral, medial offset and lateral offset. RESULTS The knee adduction moment during the stance phase significantly correlated with the shift of the center of pressure from the functional neutral sagittal axis in the coronal plane (i.e., from medial to lateral). The moment was reduced with the lateral sagittal axis configuration and augmented with the medial sagittal axis configuration. CONCLUSIONS The study results confirm the hypothesis of a direct correlation between the coronal location of the center of pressure and the magnitude of the knee adduction moment.

Differences in gait patterns, pain, function and quality of life between males and females with knee osteoarthritis: a clinical trial

BackgroundThe aim of this study was to gain a deeper understanding of the gender differences in knee osteoarthritis (OA) by evaluating the differences in gait spatio-temporal parameters and the differences in pain, quality of life and function between males and females suffering from knee OA.Methods49 males and 85 females suffering from bilateral medial compartment knee OA participated in this study. Each patient underwent a computerized gait test and completed the WOMAC questionnaire and the SF-36 health survey. Independent t-tests were performed to examine the differences between males and females in age, BMI, spatio-temporal parameters, the WOMAC questionnaire and the SF-36 health survey.ResultsMales and females had different gait patterns. Although males and females walked at the same walking speed, cadence and step length, they presented significant differences in the gait cycle phases. Males walked with a smaller stance and double limb support, and with a larger swing and single limb support compared to females. In addition, males walked with a greater toe out angle compared to females. While significant differences were not found in the WOMAC subscales, females consistently reported higher levels of pain and disability.ConclusionThe spatio-temporal differences between genders may suggest underlying differences in the gait strategies adopted by males and females in order to reduce pain and cope with the loads acting on their affected joints, two key aspects of knee OA. These gender effects should therefore be taken into consideration when evaluating patients with knee OA.Trial RegistrationThe study is registered in the NIH clinical trial registration, protocol No. NCT00599729.

Reduction in knee adduction moment via non-invasive biomechanical training: A longitudinal gait analysis study

Biomechanical non-invasive interventions have been previously reported to reduce pain and facilitate superior levels of function in patients with medial knee osteoarthritis [OA]. One such treatment is the AposTherapy, a customized program utilizing a foot-worn biomechanical device allowing center of pressure modification and continuous perturbation during gait. The influence of this intervention on objective gait metrics has yet to be determined. The aim of the current study was to prospectively examine changes in kinetic and kinematic parameters in patients enrolled in this treatment program. Twenty-five females with symptomatic bilateral medial compartment knee OA were enrolled in the customized daily treatment program. All patients underwent barefoot gait analysis testing and completed subjective questionnaires prior to treatment initiation and on two follow-up visits. Significantly reduced knee adduction moment (KAM) magnitude was noted during barefoot walking after three and nine months of treatment. On average, the knee adduction impulse and the 1st and 2nd KAM peaks were reduced by 13%, 8.4%, and 12.7%, respectively. Furthermore, moment reduction was accompanied by elevated walking velocity, significant pain reduction, and increased functional activity. In addition to symptomatic improvement, our results suggest that this treatment program can alter kinetic gait parameters in this population. We speculate that these adaptations account for the symptomatic and functional improvement reported for this intervention.

The influence of sagittal center of pressure offset on gait kinematics and kinetics

OBJECTIVES Kinetic patterns of the lower extremity joints have been shown to be influenced by modification of the location of the center of pressure (CoP) of the foot. The accepted theory is that a shifted location of the CoP alters the distance between the ground reaction force and the center of the joint, thereby modifying torques during gait. Various footwear designs have been reported to significantly alter the magnitude of sagittal joint torques during gait. However, the relationship between the CoP and the kinetic patterns in the sagittal plane has not been examined. The aim of this study was to evaluate the association between the sagittal location of the CoP and gait patterns during gait in healthy men. METHODS A foot-worn biomechanical device which allows controlled manipulation of the CoP location was utilized. Fourteen healthy men underwent successive gait analysis with the device set to convey three different sagittal locations of the CoP: neutral, anterior offset and posterior offset. RESULTS CoP translation in the sagittal plane (i.e., from posterior to anterior) significantly related with an ankle dorsiflexion torque and a knee extension torque shift throughout the stance phase. Likewise, an anterior translation of the CoP significantly reduced the extension torque at the hip during pre-swing. CONCLUSIONS The study results confirm a direct correlation between sagittal offset of the CoP and the magnitude of joint torques throughout the lower extremity.

Sex and Body Mass Index Correlate With Western Ontario and McMaster Universities Osteoarthritis Index and Quality of Life Scores in Knee Osteoarthritis

OBJECTIVE To examine the associations of sex, body mass index (BMI), and age with knee osteoarthritis (OA) symptomatic severity. DESIGN A cross-sectional retrospective analysis. SETTING Patients completed the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire and Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). Data were acquired from a stored database of a private therapy center. PARTICIPANTS Patients (N=1487) with symptomatic knee OA were evaluated. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES WOMAC questionnaire and SF-36. RESULTS BMI correlated significantly with worse knee OA symptoms for all WOMAC and SF-36 subcategories (all P ≤.001). Age correlated significantly with worse symptoms only for WOMAC function and SF-36 physical functioning (P=.001 and P=.009, respectively). A significant difference across BMI quintiles was found for all WOMAC and SF-36 subcategories (all P ≤.01). Women showed worse knee OA symptoms in all WOMAC and SF-36 subcategories (all P ≤.001). There was a significant interaction of sex by BMI in WOMAC pain and WOMAC function (P=.01 and P=.02, respectively). CONCLUSIONS Based on the results of this analysis, it can be concluded that women and patients with a higher BMI with knee OA are at a greater risk for worse symptoms.

Effect of center of pressure modulation on knee adduction moment in medial compartment knee osteoarthritis

The knee adduction moment (KAM) provides a major contribution to the elevated load in the medial compartment of the knee. An abnormally high KAM has been linked with the progression of knee osteoarthritis (OA). Footwear‐generated biomechanical manipulations reduce the magnitude of this moment by conveying a more laterally shifted trajectory of the foots center of pressure (COP), reducing the distance between the ground reaction force and the center of the knee joint, thus lowering the magnitude of the torque. We sought to examine the outcome of a COP shift in a cohort of female patients suffering from medial knee OA. Twenty‐two female patients suffering from medial compartment knee OA underwent successive gait analysis testing and direct pedobarographic examination of the COP trajectory with a foot‐worn biomechanical device allowing controlled manipulation of the COP. Modulation of the COP coronal trajectory from medial to lateral offset resulted in a significant reduction of the KAM. This trend was demonstrated in subjects with mild‐to‐moderate OA and in patients suffering from severe stages of the disease. Our results indicate that controlled manipulation of knee coronal kinetics in individuals suffering from medial knee OA can be facilitated by customized COP modification.