Knee Joint Circumference Research Articles

Loss of Knee-Extension Strength Is Related to Knee Swelling After Total Knee Arthroplasty

Holm B, Kristensen MT, Bencke J, Husted H, Kehlet H, Bandholm T. Loss of knee-extension strength is related to knee swelling after total knee arthroplasty. Objective To examine whether changes in knee-extension strength and functional performance are related to knee swelling after total knee arthroplasty (TKA). Design Prospective, descriptive, hypothesis-generating study. Setting A fast-track orthopedic arthroplasty unit at a university hospital. Participants Patients (N=24; mean age, 66y; 13 women) scheduled for primary unilateral TKA were investigated 1 week before surgery and on the day of hospital discharge 2.4 days postsurgery. Interventions Not applicable. Main Outcome Measures We assessed all patients for knee-joint circumference, knee-extension strength, and functional performance using the Timed Up & Go, 30-second Chair Stand, and 10-m fast speed walking tests, together with knee pain during all active test procedures. Results All investigated variables changed significantly from pre- to postsurgery independent of knee pain. Importantly, knee circumference increased (knee swelling) and correlated significantly with the decrease in knee-extension strength ( r=−.51; P=.01). Reduced fast-speed walking correlated significantly with decreased knee-extension strength ( r=.59; P=.003) and decreased knee flexion ( r=.52; P=.011). Multiple linear regression showed that knee swelling ( P=.023), adjusted for age and sex, could explain 27% of the decrease in knee-extension strength. Another model showed that changes in knee-extension strength ( P=.009) and knee flexion ( P=.018) were associated independently with decreased performance in fast-speed walking, explaining 57% of the variation in fast-speed walking. Conclusions Our results indicate that the well-known finding of decreased knee-extension strength, which decreases functional performance shortly after TKA, is caused in part by postoperative knee swelling. Future studies may look at specific interventions aimed at decreasing knee swelling postsurgery to preserve knee-extension strength and facilitate physical rehabilitation after TKA.

Reliability of knee joint range of motion and circumference measurements after total knee arthroplasty: does tester experience matter?

Two of the most utilized outcome measures to assess knee joint range of motion (ROM) and intra-articular effusion are goniometry and circumference, respectively. Neither goniometry nor circumference of the knee joint have been examined for both intra-tester and inter-tester in patients with total knee arthroplasty (TKA). The purpose of this study was to determine the intra-tester and inter-tester reliability of active and passive knee joint ROM and circumference in patients with TKA when administered by physiotherapists (testers) with different clinical experience. The design was an intra-tester, inter-tester and intra-day reliability study. Nineteen outpatients (10 females) having received a TKA were examined by an inexperienced and an experienced physiotherapist. Following a standardized protocol, active and passive knee joint ROM and circumference measurements were obtained using a universal goniometer and a tape measure, respectively. To establish reliability, intraclass correlation coefficients (ICC(2,1)) and smallest real difference (SRD) were calculated. The knee joint ROM and circumference measurements were generally reliable (ICC > 0.8) within and between physiotherapists (except passive knee extension). Changes in knee joint ROM of more than 6.6 degrees and 10 degrees (except active knee flexion) and knee joint circumference of more than 1.0 cm and 1.63 cm represent a real clinical improvement (SRD) or deterioration for a single individual within and between physiotherapists, respectively. Generally, the experienced tester recorded larger knee joint ROM and lower circumference values than that of the inexperienced tester. In clinical practice, we suggest that repeated knee goniometric and circumferential measurements should be recorded by the same physiotherapist in individual patients with TKA. Tester experience appears not to influence the degree of reliability.

An Investigation of the Anti‐inflammatory Potential of Pimento diocia in a rat arthritic model

Pimento dioca (pimento) from the family Myrtaceae is one of the major spices produced in Jamaica. In Jamaican folklore it is often used in the treatment arthritis. Eugenol, one of the components of pimento oil has been explored for its analgesic properties in dentistry (Fotos, 1988). In our laboratory we investigated the effect of pimento oil and eugenol on joint swelling and cell migration in a rat arthritic model. Arthritis was induced in Sprague-Dawley rats (250–300g) by injecting 0.5 mls of (1mg/ml) Complete Freud's Adjuvant in the right knee joint cavity using a 26 gauge needle. Test animals (n=7) were given pimento oil (0.4 ml/kg) or eugenol (0.37 ml/kg) for 26 days (one day prior to injection and 25 days post injection) (Sharma, 1994). Control animals (n=7) were given corn oil (0.4 ml/kg) for the same period. The knee joint was observed for signs of edema over 26 days. Changes in the knee joint circumference were measured using a flexable tape measure. (Yun Cho, 2002). Synovial fluid was aspirated with a 26 gauge needle after washing (200 ul) with sterile saline. Whole leucocyte count and differential cell count were done on the aspirate. (Salinas, 1997) There was a significant reduction (66%) in joint circumference in animals treated with pimento oil and eugenol when compared to vehicle treated animals. There was also significant reduction (80%) in whole leucocyte cell count and differential cell count compared to vehicle treated animals. The study confirmed that pimento oil and eugenol have the potential of reducing inflammatory swelling and cell migration in a rat arthritic model. This project is funded by the University of the West Indies, Mona & the University of Technology, Jamaica.

Computerized analysis of audible and ultrasonic vocalizations of rats as a standardized measure of pain-related behavior

The behavioral assessment of experimental pain is essential for the analysis of pain mechanisms and the validation of therapeutic targets. Arthritic pain, in particular, is significantly associated with negative affective states and disorders. Here we present a standardized method for the quantitative analysis of audible and ultrasonic (25 ± 4 kHz) vocalizations in awake rats as a measure of higher integrated behavior in a model of arthritic pain. A bat detector and a condenser microphone were used to record ultrasonic and audible vocalizations, respectively, in response to innocuous and noxious mechanical stimulation of the knee before and after induction of acute arthritis in one knee. A computerized system was used to analyze number and duration of the filtered signals. For the behavioral tests, the animal was placed in a customized recording chamber to ensure consistent stimulus application and stable recordings and to eliminate any movement-induced noise. Noxious stimuli produced stronger vocalizations than innocuous stimuli. Both audible and ultrasonic vocalizations to innocuous (allodynia) and noxious (hyperalgesia) stimuli increased after the induction of acute arthritis. These changes were accompanied by increased knee joint circumference, lowered hind limb withdrawal thresholds and reduced exploratory behavior in the same animals. The computerized analysis of audible and ultrasonic vocalizations is a valid, quantitative, reliable and convenient method to measure pain-related behavior.

Nicotinic cholinergic receptors: potential targets for inflammatory pain relief

We have shown previously that the development of hyperalgesia and inflammation associated with knee joint arthritis depends on interactions among various receptors in the central and peripheral nervous system in addition to the contribution of blood borne inflammatory mediators. In the present study, the involvement of spinal nicotinic cholinergic receptors in the modulation of inflammatory pain was evaluated using a model of acute arthritis in rats. Epibatidine (EP), a potent agonist for neuronal nicotinic acetylcholine receptors sharing similar structural and functional characteristics with acetylcholine and nicotine, has been used in this study. The physiological effects of EP on pain-related behaviors and inflammation were tested after administration to the dorsal horn via a microdialysis fiber. Knee joint inflammation was induced in rats by injecting a mixture of kaolin and carrageenan into the knee joint. Paw withdrawal latency to radiant heat was measured before and at 4, 5, 6, 7 and 8 h after induction of inflammation. The decrease in PWL in this arthritis model is indicative of secondary hyperalgesia. The extent of peripheral inflammation was also assessed by measuring knee joint circumference and temperature. Treatment of the spinal cord of animals with EP prior to induction of arthritis attenuated the development of heat hyperalgesia and resulted in a significant improvement of the animals' spontaneous pain-related behaviors. More interestingly, the knee joint circumference and temperature of these animals were also significantly lower than those of the control animals when measured at 8 h. Likewise, spinal administration of epibatidine after the development of hyperalgesia not only significantly attenuated the decrease in PWL, but prevented further increases in knee joint swelling and temperature. The antinociceptive effect of epibatidine was selectively blocked by the nicotinic receptor antagonist, mecamylamine. Joint circumference and temperature were not selectively altered by mecamylamine suggesting another mechanism involving non-nicotinic receptors in the spinal regulation of joint inflammatory responses. Collectively, these findings provide considerable evidence to suggest an important role for central nicotinic cholinergic receptors in the modulation of persistent pain and neurogenic inflammation mediated by events in the dorsal horn.

In vitro prostanoid release from spinal cord following peripheral inflammation: effects of substance P, NMDA and capsaicin.

1. Spinal prostanoids are implicated in the development of thermal hyperalgesia after peripheral injury, but the specific prostanoid species that are involved are presently unknown. The current study used an in vitro spinal superfusion model to investigate the effect of substance P (SP), N-methyl-d-aspartate (NMDA), and capsaicin on multiple prostanoid release from dorsal spinal cord of naive rats as well as rats that underwent peripheral injury and inflammation (knee joint kaolin/carrageenan). 2. In naive rat spinal cords, PGE2 and 6-keto-PGF1alpha, but not TxB2, levels were increased after inclusion of SP, NMDA, or capsaicin in the perfusion medium. 3. Basal PGE2 levels from spinal cords of animals that underwent 5-72 h of peripheral inflammation were elevated relative to age-matched naive cohorts. The time course of this increase in basal PGE2 levels coincided with peripheral inflammation, as assessed by knee joint circumference. Basal 6-keto-PGF1alpha levels were not elevated after injury. 4. From this inflammation-evoked increase in basal PGE2 levels, SP and capsaicin significantly increased spinal PGE2 release in a dose-dependent fashion. Capsaicin-evoked increases were blocked dose-dependently by inclusion of S(+) ibuprofen in the capsaicin-containing perfusate. 5. These data suggest a role for spinal PGE2 and NK-1 receptor activation in the development of hyperalgesia after injury and demonstrate that this relationship is upregulated in response to peripheral tissue injury and inflammation.