Stance and swing phase knee flexion recover at different rates following total knee arthroplasty: An inertial measurement unit study

Total knee arthroplasty (TKA) is the most common joint replacement in the United States. Range of motion (ROM) monitoring includes idealized clinic measures (e.g. goniometry during passive ROM) that may not accurately represent knee function. Accordingly, a novel, portable, inertial measurement unit (IMU) based ROM measurement method was developed, validated, and implemented. Knee flexion was computed via relative motion between two IMUs and validated via optical motion capture (p > 0.05). Prospective analyses of 10 healthy individuals (5M, 50 ± 19 years) and 20 patients undergoing TKA (3 lost to follow up, 10M, 65 ± 6 years) were completed. Controls wore IMUs for 1-week. Patients wore IMUs for 1-week pre-TKA, 6-weeks immediately post-TKA, and 1-week at 1-year post-TKA. Flexion was computed continuously each day (8–12 h). Metrics included daily maximum flexion and flexion during stance/swing phases of gait. Maximum flexion was equal between cohorts at all time points. Contrastingly, patient stance and swing flexion were reduced pre-TKA, yet improved post-TKA. Specifically, patient stance and swing flexion were reduced below control/pre-TKA values during post-TKA week 1. Stance flexion exceeded pre-TKA and equaled control levels after week 2. However, swing flexion only exceeded pre-TKA and equaled control levels at 1-year post-TKA. This novel method improves upon the accuracy/portability of current methods (e.g. goniometry). Interestingly, surgery did not impact maximum ROM, yet improved the ability to flex during gait allowing more efficient and safe ambulation. This is the first study continuously monitoring long-term flexion before/after TKA. The results offer richer information than clinical measures about expected TKA rehabilitation.     

Inter-Segmental Coordination Pattern in Patients with Anterior Cruciate Ligament Deficiency during a Single-Step Descent

Anterior cruciate ligament injury is a debilitating pathology which may alter lower limb coordination pattern in both intact and affected lower extremities during activities of daily living. Emerging evidence supports the notion that kinematic variables may not be a good indicator to differentiate patients with anterior cruciate ligament deficiency during step descent task. The aim of the present study was to examine alterations in kinematics as well as coordination patterns and coordination variability of both limbs of these patients during a single step descent task. Continuous relative phase technique was used to measure coordination pattern and coordination variability between a group of anterior cruciate ligament deficient (n = 23) and a healthy control group (n = 23). A third order polynomial Curve fitting was utilized to provide a curve that best fitted to the data points of coordination pattern and coordination variability of the healthy control group. This was considered as a reference to compare to that of patient group using nonlinear regression analysis. The results of the present study demonstrated an altered coordination pattern of the supporting shank-thigh and the stepping foot-shank couplings in anterior cruciate ligament deficient subjects. It was further noticed that there was an increased coordination variability in foot-shank and shank-thigh couplings of both supporting and stepping legs. There was no significant difference in the hip, knee and ankle joints kinematics in either side of these patients. Anterior cruciate ligament deficient individuals showed altered strategies in both intact and affected legs, with increased coordination variability. Kinematic data did not indicate any significant difference between the two groups. It could be concluded that more sophisticated dynamic approach such as continuous relative phase would uncover discrepancies between the healthy and anterior cruciate ligament deficient individuals.     

Gender differences in lower extremity coupling variability during an unanticipated cutting maneuver

The purpose of this study was to determine if gender differences exist in the variability of various lower extremity (LE) segment and joint couplings during an unanticipated cutting maneuver. 3-D kinematics were collected on 24 college soccer players (12 M, 12 F) while each performed the cutting maneuver. The following intralimb couplings were studied: thigh rotation (rot)/leg rot; thigh abduction-adduction/leg abd-add; hip abd-add/knee rot; hip rot/knee abd-add; knee flexion-extension/knee rot; knee flx-ext/hip rot. A vector-coding technique applied to angle-angle plots was used to quantify the coordination of each coupling. The average between-trial standard deviation of the coordination pattern during the initial 40 % of stance was used to indicate the coordination variability. One-tailed t-tests were used to determine differences between genders in coordination variability for each coupling. Women had decreased variability in four couplings: 32 % less thigh rot/leg rot variability; 40 % less thigh abd-add/leg abd-add variability; 46 % less knee flx-ext/knee rot variability; and 44 % less knee flx-ext/hip rot variability. These gender differences in LE coordination variability may be associated with the increased incidence of ACL injury in women. If women exhibit less flexible coordination patterns during competition, they may be less able to adapt to the environmental perturbations experienced during sports. These perturbations applied to a less flexible system may result in ligament injury.     

Power and work produced in different leg muscle groups when rising from a chair

The aim of this study was to determine the power output and work done by different muscle groups at the hip and knee joints during a rising movement, to be able to tell the degree of activation of the muscle groups and the relationship between concentric and eccentric work. Nine healthy male subjects rose from a chair with the seat at knee level. The moments of force about the hip and knee joints were calculated semidynamically. The power output (P) and work in the different muscle groups surrounding the joints was calculated as moment of force times joint angular velocity. Work was calculated as: work = f Pdt. The mean peak concentric power output was for the hip extensors 49.9 W, hip flexors 7.9 W and knee extensor 89.5 W. This power output corresponded to a net concentric work of 20.7 J, 1.0 J and 55.6 J, respectively. There was no concentric power output from the knee flexor muscles. Energy absorption through eccentric muscle action was produced by the hip extensors and hip flexors with a mean peak power output of 4.8 W and 7.4 W, respectively. It was concluded that during rising, the hip and knee muscles mainly worked concentrically and that the greatest power output and work were produced during concentric contraction of the knee and hip extensor muscles. There was however also a demand for eccentric work by the hip extensors as well as both concentric and eccentric work by the hip flexors. The knee flexor muscles were unloaded.     

Prehabilitation before knee arthroplasty increases postsurgical function: a case study

Conditioning the body to undergo physical stress such as joint arthroplasty has been termed prehabilitation. This case study examined the effect of a 4-week prehabilitation intervention on functional outcomes after total knee arthroplasty (TKA). Two female subjects completed baseline strength and functional assessments before TKA. Subjects were randomized to either a 4-week prehabilitation intervention (ES) aimed at increasing strength and range of motion or a usual care condition (CS). After 4 weeks of training, subjects were reassessed and underwent TKA. Subjects completed a final assessment 12 weeks after TKA. Functional outcomes included 6-minute walk, number of times up from a chair in 30 seconds, proprioception, and self-reported function and pain using the Western Ontario and McMaster Universities Osteoarthritis Index. The data suggest that 4 weeks of prehabilitation had a positive effect on functional task performance and knee proprioception before surgery. After surgery, the ES continued to exhibit higher levels of functioning and less pain compared with the CS. Prehabilitation before TKA may contribute to improved recovery after surgery.     

Muscle activation and coactivation during five-time-sit-to-stand movement in patients undergoing total knee arthroplasty

Quadriceps weakness is prevalent with knee osteoarthritis (OA) and after total knee arthroplasty (TKA). To compensate for quadriceps dysfunction, patients often alter movement strategies. Little is known about muscle coordination during sit-to-stand (concentric) and stand-to-sit (eccentric) movements in the acute postoperative period. This investigation characterized the distribution of muscle activation between the concentric and eccentric phases during a five-time-sit-to-stand (FTSTS) movement in late stage OA and one month after TKA. Patients and healthy participants performed a FTSTS while recording bilateral ground reaction forces (GRFs) and electromyography (EMG). Concentric and eccentric ensemble averages of the GRF and EMG were calculated for the concentric and eccentric phases. Coactivation indices, integrated EMG, and GRF were calculated for each limb and phase. Patients demonstrated higher eccentric coactivation than the healthy group. Postoperative loading was higher in the nonsurgical limb. Postoperative quadriceps activity was lower in the concentric phase and higher in the eccentric phase than the healthy group. Higher coactivation in the patients resulted from sustained distribution of quadriceps activity throughout the eccentric phase. This indicated an inability to coordinate muscle firing when rapidly lowering to a chair and occurred despite unloading of the surgical limb. Although these patterns may serve as a protective strategy, they may also impede recovery of muscle function after TKA.     

The role of strength in rising from a chair in the functionally impaired elderly

Rising from a chair is a task essential for independent living. Many elderly persons have difficulty with this task. Previous studies have drawn conflicting conclusions as to the role of strength in limiting the ability to rise from a chair. The purpose of this study is to determine the role of knee extensor strength in rising from a chair in the functionally impaired elderly. It is hypothesized that knee extensor strength limits the minimum chair height from which a subject can rise in the functionally impaired elderly, but not in the young. Studying both young healthy adults and functionally impaired elderly showed that required joint moment increased monotonically with decreasing chair height. Further, the elderly used significantly more of their available strength to rise from any chair height, and their mean required knee moment was 97% of the available strength when rising from the lowest chair height from which they could successfully rise. These data suggest that strength is a limiting factor in determining the minimum chair height from which the functionally impaired elderly may rise     

Neuromuscular activation of quadriceps bellies during tasks performed in the same biomechanical condition in patients undergoing total knee arthroplasty

ObjectiveTo investigate neuromuscular activation of quadriceps bellies during different tasks in patients before and after total knee arthroplasty (TKA).MethodsTwenty-six patients scheduled for TKA and 16 control subjects performed three isometric tasks: knee extension (KE), hip flexion (HF), hip flexion with contralateral hip extension (HFE). Surface electromyography signals of rectus femoris, vastus medialis and vastus lateralis were collected the day before (T0), at one (T1) and three (T2) days after surgery, whereas control subjects underwent a single evaluation. The Root Mean Square peak normalized for its highest value during the three tasks (nRMS-peak) was used as index of maximum neuromuscular activation for each belly. Sixteen patients performed the postoperative assessment, due to the placement of an elastomeric pump aimed at reducing pain in 10 patients.ResultsPatients showed lower rectus femoris nRMS-peak during KE compared to HF and HFE before and after surgery (p < 0.001), as occurred in control subjects. Differently from control subjects, patients showed higher vastus medialis and vastus lateralis nRMS-peak during HF compared to KE at T1 (p = 0.008) and T2 (p = 0.039).ConclusionTKA modified quadriceps neuromuscular activation during different tasks performed the same biomechanical condition. These findings may be considered in planning physiotherapy interventions after TKA.     

内侧开放楔形胫骨高位截骨术治疗膝关节内翻畸形的疗效及对术后下肢力线和创伤应激的影响

摘要 目的：对比内侧开放楔形胫骨高位截骨术（OWHTO）、人工全膝关节置换术（TKA）治疗膝关节内翻畸形的疗效及对术后下肢力线和创伤应激的影响。方法：回顾性分析贵州医科大学附属医院2020年3月~2022年1月期间接收的膝关节内翻畸形患者临床资料,共计75例。根据手术方案的不同分为OWHTO组（n=40）和TKA组（n=35）。对比两组围术期指标、视觉疼痛模拟评分（VAS）评分、美国特种外科医院（HSS）膝关节评分、膝关节活动度（ROM）、应激指标和术后下肢力线改变情况。结果：OWHTO组手术时间、切口长度短于TKA组,术中出血量、住院费用少于TKA组（P<0.05）。OWHTO组术后1个月VAS评分低于TKA组,ROM、HSS膝关节评分高于对照组（P<0.05）。OWHTO组术后3 d、术后7 d血清皮质醇（COR）、促肾上腺皮质激素（ACTH）水平低于TKA组（P<0.05）。两组术后6个月股胫角（FTA）下降,髋-膝-踝角（HKA）升高（P<0.05）。两组术后6个月FTA、HKA组间对比差异不显著（P>0.05）。两组并发症发生率组间对比未见差异（P>0.05）。结论：OWHTO、TKA这两种治疗方案治疗膝关节内翻畸形,具有相当的疗效,均可有效改善下肢力线,但OWHTO的创伤小、应激程度轻。     

In vivo contact kinematics and contact forces of the knee after total knee arthroplasty during dynamic weight-bearing activities

Analysis of polyethylene component wear and implant loosening in total knee arthroplasty (TKA) requires precise knowledge of in vivo articular motion and loading conditions. This study presents a simultaneous in vivo measurement of tibiofemoral articular contact forces and contact kinematics in three TKA patients. These measurements were accomplished via a dual fluoroscopic imaging system and instrumented tibial implants, during dynamic single leg lunge and chair rising-sitting. The measured forces and contact locations were also used to determine mediolateral distribution of axial contact forces. Contact kinematics data showed a medial pivot during flexion of the knee, for all patients in the study. Average axial forces were higher for lunge compared to chair rising-sitting (224% vs. 187% body weight). In this study, we measured peak anteroposterior and mediolateral forces averaging 13.3% BW during lunge and 18.5% BW during chair rising-sitting. Mediolateral distributions of axial contact force were both patient and activity specific. All patients showed equitable medial-lateral loading during lunge but greater loads at the lateral compartment during chair rising-sitting. The results of this study may enable more accurate reproduction of in vivo loads and articular motion patterns in wear simulators and finite element models. This in turn may help advance our understanding of factors limiting longevity of TKA implants, such as aseptic loosening and polyethylene component wear, and enable improved TKA designs.     

A randomized controlled trial comparing patellar retention versus patellar resurfacing in primary total knee arthroplasty: 5-10 year follow-up

ABSTRACT: BACKGROUND: The primary purpose of this randomized controlled trial (RCT) was to compare knee-specific outcomes (stiffness, pain, function) between patellar retention and resurfacing up to 10 years after primary total knee arthroplasty (TKA). Secondarily, we compared re-operation rates. METHODS: 38 subjects with non-inflammatory arthritis were randomized at primary TKA surgery to receive patellar resurfacing (n = 21; Resurfaced group) or to retain their native patella (n = 17; Non-resurfaced group). Evaluations were performed preoperatively, one, five and 10 years postoperatively by an evaluator who was blinded to group allocation. Self-reported kneespecific stiffness, pain and function, the primary outcomes, were measured by the Western Ontario McMaster Osteoarthritis Index (WOMAC). Revision rate was determined at each evaluation and through hospital record review. RESULTS: 30 (88%) and 23 (72%) of available subjects completed the five and 10-year review respectively. Knee-specific scores continued to improve for both groups over the 10-years, despite diminishing overall health with no significant group differences seen. All revisions occurred within five years of surgery (three Non-resurfaced subjects; one Resurfaced subject) (p = 0.31). Two revisions in the Non-resurfaced group were due to persistent anterior knee pain. CONCLUSIONS: We found no differences in knee-specific results between groups at 5-10 years postoperatively. The Non-resurfaced group had two revisions due to anterior knee pain similar to rates reported in other studies. Knee-specific results provide useful postoperative information and should be used in future studies comparing patellar management strategies. ClinicalTrials.gov identifier NCT01500252.     

Mutual Stabilization of Rhythmic Vocalization and Whole-Body Movement

The current study investigated the rhythmic coordination between vocalization and whole-body movement. Previous studies have reported that spatiotemporal stability in rhythmic movement increases when coordinated with a rhythmic auditory stimulus or other effector in a stable coordination pattern. Therefore, the present study conducted two experiments to investigate (1) whether there is a stable coordination pattern between vocalization and whole-body movement and (2) whether a stable coordination pattern reduces variability in whole-body movement and vocalization. In Experiment 1, two coordination patterns between vocalizations and whole-body movement (hip, knee, and ankle joint flexion-on-the-voice vs. joint extension-on-the-voice) in a standing posture were explored at movement frequencies of 80, 130, and 180 beats per minute. At higher movement frequencies, the phase angle in the extension-on-the-voice condition deviated from the intended phase angle. However, the angle of the flexion-on-the-voice was maintained even when movement frequency increased. These results suggest that there was a stable coordination pattern in the flexion-on-the-voice condition. In Experiment 2, variability in whole-body movement and voice-onset intervals was compared between two conditions: one related to tasks performed in the flexion-on-the-voice coordination (coordination condition) that was a stable coordination pattern, and the other related to tasks performed independently (control condition). The results showed that variability in whole-body movement and voice-onset intervals was smaller in the coordination condition than in the control condition. Overall, the present study revealed mutual stabilization between rhythmic vocalization and whole-body movement via coordination within a stable pattern, suggesting that coupled action systems can act as a single functional unit or coordinative structure.     

Evaluation of the kinematic parameters of normal-paced gait in subjects with gonarthrosis and the influence of gonarthrosis on the function of the ankle joint and hip joint

The aim of the study was to assess the variability of parameters characterising the gait of persons suffering from degenerative changes of the knee joint and their influence on the ankle and hip joints. The values of the angular changes in the knee, ankle and hip joints in the three planes of motion were assessed. Locomotion tests were performed on 27 persons, aged between 60 and 74, using Vicon 250, the three-dimensional analysis system. The sharpest deviations from the results of the control group were revealed in the transverse and frontal planes. Degenerative knee joint disease has changed the gait stereotype causing a reduction in the economy of gonarthrosis patients' locomotion, the influence of the disease on the function of the neighbouring joints is also distinctly marked.     

全膝关节置换术后皮温与血清指标变化的相关性研究

目的:研究膝骨性关节炎(knee osteoarthritis,KOA)患者行单侧全膝关节置换术手术前后膝关节皮温、血清指标的变化规律以及与膝关节功能恢复之间相关性。方法:将2016年9月-2017年3月在我院行单侧全膝关节置换术且术后未发生假体周围感染的患者作为研究对象,测量并记录基本信息、术前及术后膝关节皮温、血清指标及膝关节功能评分,并进行统计学分析。结果:本研究共收集病例65例,随访时间为6个月。双膝皮温、双膝皮温差于术后第5天达到峰值,PCT、CRP、ESR均于术后第3天达到峰值,IL-6、WBC于术后第1天达到峰值,HGB下降至最低水平为术后5-7天。患者非手术侧膝关节皮温于术后30天恢复至术前水平,而手术侧膝关节皮温及双膝皮温差直至术后6个月仍未恢复至术前水平;PCT、IL-6、CRP于术后60天恢复至术前水平,ESR于术后90天恢复至术前水平,WBC于术后15天恢复至术前水平。结论:KOA患者TKA术后双膝皮温差直至术后6月仍高于术前水平,而研究中的各项血清指标均于术后3月内恢复至术前水平。     

Knee efforts and weight-bearing asymmetry during sit-to-stand tasks in individuals with hemiparesis and healthy controls

The asymmetrical weight-bearing distribution of individuals with hemiparesis rising from a chair might be used to produce similar muscular efforts at the lower limbs. The aim of this study was to determine if individuals with hemiparesis have symmetrical levels of effort at the knee during spontaneous sit-to-stand transfers. Nineteen subjects with hemiparesis and 16 healthy controls participated. Their weight-bearing (WB) distribution during sit-to-stand was assessed with a force platform setup while the knee effort distribution was quantified using electromyographic (EMG) data normalized to maximal EMG values then expressed relative to the sum of the bilateral efforts. The healthy individuals presented symmetrical weight-bearing and knee effort distributions during the sit-to-stand transfer. The participants with hemiparesis, classified in three subgroups based on knee extensors’ strength asymmetries (mild, moderate and severe), yielded different results. The mild group (n = 6) behaved like the controls, with almost symmetrical WB and knee efforts. The moderate group (n = 7) had similar WB and effort asymmetries while the severe group (n = 6) exhibited a WB distribution difference between sides but had almost symmetrical knee effort. These results for the severe group suggest that a control is exerted on the levels of effort when rising from a chair, which might be required when a certain threshold of effort is reached on the nonparetic side.     

UKA与TKA治疗膝关节内侧单间室骨性关节炎的临床对比

目的:探究膝关节单髁置换术(UKA)与全膝关节置换术(TKA)治疗膝关节内侧单间室骨性关节炎的临床治疗效果。方法:将2011年4月-2015年7月期间因膝关节单间室骨性关节炎入院接受治疗的89例患者纳入本研究,随机分为研究组和对照组,研究组44例,行UKA手术,对照组45例,采用TKA手术方式治疗。对两组患者进行术后随访,对比临床治疗效果。结果:两组术前均有明显膝关节疼痛,术后膝关节疼痛均明显改善,组间差别无显著统计学意义(X2=1.323,P=0.2500.05);术后膝关节屈曲角度、HSS评分相对于术前均显著改善,研究组术后膝关节屈曲角度(111.2±18.8)度高于对照组的(98.6±14.7)度,差异有统计学意义(P0.05);HSS评分(87.6±13.7)分高于对照组的(73.2±16.8)分,差异有统计学意义(P0.05);研究组膝关节屈曲至90度时间比对照组短,数据差异有统计学差异(t=-2.303,P=0.0240.05)。结论:膝关节内侧单间室骨性关节炎采用UKA与TKA均能取得一定临床效果,减轻患者痛苦,改善膝关节功能,但UKA临床疗效较好,手术创伤较小,术后恢复较快。     

Influence of landmark and surgical variability on virtual assessment of total knee arthroplasty

Given advances in recent years in imaging modalities and computational hardware/software, virtual analyses are increasingly valuable and practical for evaluating total knee arthroplasty (TKA). However, the influence of variabilities at each step in computational analyses on predictions of TKA performance for a population has not yet been thoroughly investigated, nor the relationship between these variabilities and expected variations in surgical practice. Understanding these influences is nevertheless essential for ensuring the clinical relevance of theoretical predictions. Here, a morphological analysis of proximal tibial resections within TKA is proposed and investigated. The goals of this analysis are to quantify the influence of variability in landmark detection on resection parameters and to evaluate this sensitivity relative to expected clinical variability in TKA resections. Results here are directly applicable to population-level computational analyses of morphological and functional TKA performance.     

Increased hip adductor activation during sit-to-stand improves muscle activation timing and rising-up mechanics in individuals with hemiparesis

Long sit-to-stand (STS) time has been identified as a feature of impaired functional mobility. The changes in biomechanics of STS performance with simultaneous hip adductor contraction have not been studied, which may limit indications for use of hip adductor activation during STS training.Ten individuals with hemiplegia (mean age 61.8 years, injury time 29.8 ± 15.2 months) performed the STS with and without squeezing a ball between two legs. The joint moments, ground reaction force (GRF), chair reaction force and movement durations and temporal index of electromyography were calculated from the control condition for comparison with those from the ball squeezing condition.Under the squeeze condition, reduced peak vertical GRF during the ascension phase with increased loading rate was observed in the nonparetic limb, and the peak knee extensor moment occurred earlier in the paretic. Earlier activation of tibialis anterior and gluteus maximus, and gluteus medius were found in squeeze STS.Squeezing a ball between limbs during STS increased the contraction timing of tibialis anterior, gluteus maximus, gluteus medius, and soleus as well as a more symmetric rising mechanics encourage the use of squeezing a ball between limbs during STS for individuals with hemiparesis.     

A Procedure for the Design of Novel Assisting Devices for the Sit-to-Stand

The Sit-to-Stand （STS） is an activity most people perform numerous times daily. Standing up deals with the transition from two stabilized postures, namely seated to standing, with movement of all body segments except the feet. During the STS the body＇s Center of Gravity （COG） is moved upward from a sitting position to a standing position without losing balance and requiring a good coordination of many muscles. Three main phases of the STS movement can be recognized. One begins to stand up by inclining the upper body forward, which moves body mass toward the feet in order to maintain balance after lift-off. Prior to leaving the chair, hip and knee extensor muscles are activated to provide antigravity support for these joints, this action is commonly referred to as ＂weight shift＂. Finally; after leaving the chair, the leg and trunk joints are straightened to achieve upright stance. The STS task can be considered of major importance for impaired and elderly people to achieve minimal mo- bility and independence. In this paper we detail a procedure for the design of assisting devices to be used for the STS. In par- ticular, an experimental procedure is described firstly to track and record point trajectories and the orientation of the trunk during the STS. This analysis is then used to get information for the design of assisting devices. A proposal and simulation results are presented for a novel mechatronic system. In particular, for the case under study experimental tests are used to drive the actua- tion system for the reported simulation. A functional mechatronic scheme is then proposed to control the device during its operation.     

Comparison of outcome measures during treatment with the proprietary Harpagophytum extract doloteffin in patients with pain in the lower back, knee or hip.

Besides checking estimates of effectiveness and safety of using the proprietary Harpagophytum extract Doloteffin, this postmarketing surveillance compared various disease-specific* and generic** measures of effect. We enrolled 250 patients suffering from nonspecific low back pain (Back group: n = 104) or osteoarthritic pain in the knee (Knee group: n = 85) or hip (Hip group: n = 61). They took an 8-week course of Doloteffin at a dose providing 60 mg harpagoside per day. The measures of effect on pain and disability included the percentage changes from baseline of established instruments (Arhus low back pain index*, WOMAC index*, German version of the HAQ**) and unvalidated measures (total pain index*, three score index*, the patient's global assessment** of the effectiveness of treatment). Patients also received a diary for the daily recording of their pain and any additional treatments for it. The three groups differed in age, weight and characteristics of initial pain. 227 patients completed the study. Multivariate analysis confirmed that several dimensions of effect were recorded by the several outcome measures but, in all groups, both the generic and disease-specific outcome measures improved by week 4 and further by 8. In multivariable analysis, the improvement tended to be more when the initial pain and disability score was more: older patients tended to improve less than younger, the hip group tended to improve convincingly more than the back group, whereas the improvement in the knee group was less readily differentiated from that in the back group. The subgroup of Back patients who required NSAIDs during the 8 weeks used significantly more per patient than patients in the other two groups, but that requirement also declined more with time. About 10% of the patients suffered from minor adverse events that could possibly have been attributable to Doloteffin. Between 50% and 70% of the patients benefitted from Doloteffin with few adverse effects. Thus, Doloteffin is well worth considering for osteoarthritic knee and hip pain and nonspecific low back pain.