Biomechanical assessment of the first dorsal compartment of the wrist: A fresh cadaver study with relevance to de Quervain's disease.

Resistance of de Quervain's disease to conservative treatment has been associated with an intertendinous septum in the first compartment. This study aimed to investigate the relationship between intertendinous septum's presence or absence, internal pressure and wrist positon in the first compartment. Fourteen arms were obtained from seven fresh frozen cadavers. A pressure sensor was inserted into the first compartment; if a septum was present, the pressure sensor was inserted into the abductor pollicis longus (APL) side and the extensor pollicis brevis (EPB) side, respectively. Three wrist positions were also tested: neutral, 45° flexion, and 45° extension. Intertendinous septa were present in seven wrists. The average pressure change in the first compartment measured on the EPB side of a present septum was significantly greater than that measured on the APL side of a present septum or where no septum existed: no septum = 54.6 ± 48.3 kPa; septum, EPB = 81.7 ± 76.5 kPa; and septum, APL = 32.8 ± 37.4 kPa. The average pressure change was also significantly greater in the flexion wrist position relative to the neutral and extension positions: neutral = 36.3 ± 58.0 kPa; 45° flexion = 79.5 ± 65.9 kPa; and 45° extension = 50.4 ± 42.6 kPa. Clear relationships existed between (1) the presence of a septum and increased internal pressure on the EPB side in the first compartment and (2) increased internal pressure with the wrist at 45° flexion compared with the neutral and extension position.

Lateral bending differentiates early-stage spondylolysis from nonspecific low back pain in adolescents.

BACKGROUND: Early-stage spondylolysis (ESS) is one of the common causes of acute low back pain (LBP) in adolescents. Although accurate diagnosis of ESS is important for providing appropriate treatment, differentiating ESS from other low back disorders is difficult by physical signs alone. OBJECTIVES: To elucidate the most common characteristic, namely, motion-provoking LBP, in patients with ESS. DESIGN: Retrospective comparative cohort study. METHOD: We included and categorized adolescents (n = 112; age, <18 years) with acute LBP (<1 month) into the ESS (n = 71) and nonspecific LBP (NS-LBP) (n = 41) groups based on magnetic resonance imaging (MRI) findings. Patients were evaluated using a visual analog scale (VAS), Oswestry Disability Index (ODI), and degree of pain using a numerical rating scale (NRS) provoked by hyperextension, hyperflexion, right and left rotations, and lateral bending in standing position.; the value were compared between the 2 groups. A cut-off value of significance was obtained using receiver operating characteristic (ROC) analysis. RESULTS: The mean scores for VAS and ODI and NRS of each test were as follows (ESS/NS-LBP): VAS, 6.5/6.0; ODI, 19.7/24.6; hyperextension, 4.1/4.1; hyperflexion, 2.4/3.0; rotation, 2.1/2.2; and lateral bending, 2.9/2.2. The ESS group had a significantly greater number of LBP cases provoked by lateral bending than the NS-LBP group. A cut-off lateral bending of 3.5 yielded a diagnosis of ESS. CONCLUSIONS: Our results indicate that lateral bending is the greatest motion-provoking characteristic of LBP in patients with ESS.

Utility of Physical Examination Findings for Predicting Low-Back Pain in Adolescent Patients with Early-Stage Spondylolysis: A Retrospective Comparative Cohort Study.

INTRODUCTION: This study aimed to elucidate low-back pain (LBP) characteristics, i.e., its qualities, extent, and location, in patients with early-stage spondylolysis (ESS). METHODS: We recruited patients (≤18 years old) who presented with acute LBP lasting up to 1 month. Patients were divided into ESS and nonspecific LBP (NS-LBP) groups based on their magnetic resonance imaging findings; patients showing no pathological findings that might explain the cause of LBP were classified as NS-LBP. All patients were evaluated using the following tests: hyperextension and hyperflexion (pain provocation tests in a standing position), pain quality (sharp/dull), pain extent (fingertip-sized area/palm-sized area), and pain location (left and/or right pain in side [side]/central pain [center]). We have also compared outcomes between the ESS and NS-LBP groups in terms of gender and physical symptoms. RESULTS: Of 101 patients, 53 were determined to have ESS (ESS group: mean age: 14.3 years old; 43 males/10 females), whereas 48 had no pathological findings explaining the LBP origin [NS-LBP group (mean age, 14.4 years old; 31 males/17 females)]. Chi-squared test has identified gender (male), a negative result on hyperflexion test, pain extent (fingertip-sized area), and pain location (side) to be significantly associated with ESS. Among these, regression analysis revealed that male gender and LBP located on the side were significantly associated with ESS (p<0.05). CONCLUSIONS: Although the hyperextension test is generally considered useful for ESS, we demonstrated that its association is not deemed significant. Our results indicate that male gender, a negative result of the hyperflexion test, fingertip-sized pain area, and LBP on the side may be specific characteristics of ESS. Of these physical signs, male gender and LBP located on the side are characteristic factors suggesting ESS presence.

Does the single-limb stance reflect chronic ankle instability in an athlete?

BACKGROUND: The single-limb stance with closed eyes has been widely used to evaluate chronic ankle instability as static balance; however, there was lack of consideration of whether difference in age, frequency of previous ankle sprain or physical ability influenced single-limb stance. RESEARCH QUESTION: We hypothesized that the single-limb stance might not reflect subjective ankle instability and function on physical activity in people who perform sports activities. METHODS: In total, 102 high school basketball players were recruited to evaluate their physical performance at the beginning of the season. Participants were divided into five groups based on the frequency of previous ankle sprain. Karlsson ankle function score (K score) was considered as a subjective ankle function score, that was divided into various components. Each component and the single-limb stance test with center of pressure (COP) analysis was observed between the frequency of ankle sprains with one-way ANOVA and compared using Spearman's rank correlation coefficient to verify the relationship between the K score and COP. RESULTS: For COP parameters, no difference was observed in the history of ankle sprains. The K score was lower in participants with three previous ankle sprains than in those with a different number of ankle sprains for instability, stiffness, running, work activities, support, and total K score for all parameters. There were weak negative correlations (r = -0.19∼-0.35) between K score and COP parameters among participants with no history of ankle sprain or only once. In contrast, there were strong positive correlations (r = 0.69∼0.87) among history of ankle sprain at third. SIGNIFICANCE: The single-limb stance might not accurately reflect an athlete's ankle instability and function on physical activity. Clinically, therapists should choose suitable evaluation tools depending on the athlete's activity level to check for chronic ankle instability.

Ultrasonography could be used to predict extended insertion of the EPB tendon noninvasively.

INTRODUCTION: An abnormal distal insertion of the extensor pollicis brevis (EPB) tendon into the thumb interphalangeal joint (IP) has been observed in refractory cases of de Quervain's disease. This is associated with the extensor being wider at the midpoint of the proximal phalanx; however, there is no method to noninvasively measure this. This study evaluated the accuracy of measuring the extensor width using ultrasonography, to establish a noninvasive method for predicting an EPB extending the IP insertion. MATERIALS AND METHODS: Of 23 arms from 12 fresh frozen cadavers, the extensor tendon width at the midpoint of the proximal phalanx was measured using ultrasonography and directly at dissection. The association between these values was evaluated using correlation analysis. A cut-off value of extensor tendon width was obtained using receiver operating characteristic analysis. RESULTS: A strong correlation was observed between the ultrasonography and the measured values. The EPB tendons were normal in 13 arms (57%) and extended in 10 (43%), with a significant difference between these groups in the mean width of the extensor tendon (6.8 ± 1.1 vs. 8.4 ± 1.0 mm). A cut-off extensor tendon width of 8.0 mm yielded an EPB extending the IP. CONCLUSION: An EPB extending the IP tendon can be predicted by measuring the extensor tendon width at the midpoint of the proximal phalanx using ultrasonography. The cut-off tendon width value of ≥ 8.0 mm may be useful for assessments prior to surgery and for conservative care.

Anatomic study of the first extensor compartment and the relationship between the extensor tendon width and its distal insertion.

INTRODUCTION: The extensor pollicis brevis (EPB) tendon normally inserts into the base of the proximal phalanx of the thumb. However, a distal insertion of the EPB tendon into the thumb interphalangeal joint has been reported in refractory cases of de Quervain's disease. We hypothesized that the EPB tendon is wider beyond the thumb metacarpophalangeal joint in patients with extended EPB. This study aimed to evaluate the relationship between the extensor tendon width and the point of distal insertion of the EPB tendon. MATERIALS AND METHODS: In 45 hands from 18 male and 27 female adult cadavers, the first extensor compartment was dissected and the existence of the intertendinous septum was assessed. The extensor tendon width was measured at the midpoint of the proximal phalanx, and relationships between extended EPB tendon, existence rate of the intertendinous septum, sex, and extensor tendon width were examined. RESULTS: Of 45 cases, intertendinous septum and extended EPB tendon were observed in 37 (82.2%) and 23 (51.1%), respectively. There was no significant difference between the existence rates of both these factors and sex. The mean extensor tendon width in the extended EPB group was significantly greater than in the normal EPB group. The cut-off value of extensor tendon width in the extended EPB group was 7.12 mm. CONCLUSIONS: The extensor tendon width was wider in the extended EPB group than in the normal EPB group, suggesting that the differences in the EPB tendon width can be used to identify various anatomical variations in extended EPB.

Characteristics of low back pain in adolescent patients with early-stage spondylolysis evaluated using a detailed visual analogue scale.

STUDY DESIGN: Retrospective comparative cohort study. OBJECTIVE: To elucidate the characteristics of low back pain (LBP) in adolescent patients with early-stage spondylolysis (ESS). SUMMARY OF BACKGROUND DATA: ESS is a common cause of acute LBP in adolescents. When treating patients with ESS, early diagnosis is important; however, early diagnosis is difficult without magnetic resonance imaging. METHODS: Adolescent patients (n = 77) with acute LBP showing no pathological findings on plain radiography were included (<1 m after onset). Patients were divided into ESS and nonspecific LBP (NS-LBP) groups by conducting magnetic resonance imaging; patients showing no pathological findings that explain the cause of LBP were classified as NS-LBP. LBP was evaluated using a traditional visual analogue scale (VAS; 0-10 cm), Oswestry Disability Index, and a detailed VAS scoring system in which pain is independently evaluated in 3 different postural situations (in motion, standing, and sitting); the values were compared between the 2 groups. RESULTS: Of 77 patients, 41 (mean age: 14.6 yr; 33 adolescent boys/8 adolescent girls) had ESS and 36 (mean age: 14.3 yr; 20 adolescent boys/16 adolescent girls) were considered to have NS-LBP. Respective traditional VAS and Oswestry Disability Index scores were 4.9, 16.1 in the ESS group, and 6.2, 26.3 in the NS-LBP group. Both scores were significantly higher in the NS-LBP group. The results of the detailed VAS revealed that the ESS group showed significantly greater pain intensity while in motion than while standing or sitting (4.2, 2.0, and 2.0, respectively), whereas the NS-LBP group showed similar pain intensities in all 3 postural situations (5.3, 4.0, and 4.9, respectively). CONCLUSION: This study revealed that LBP characteristics may provide important information for distinguishing ESS from other low back disorders. Because early diagnosis is essential for the treatment of ESS, MRI examination is recommended for patients showing severe pain in motion, but less pain when standing or sitting.