Differences In Joint Space Width Research Articles

Medial unicompartmental knee arthroplasty improves congruence and restores joint space width of the lateral compartment

BackgroundOsteoarthritic progression of the lateral compartment remains a leading indication for medial unicompartmental knee arthroplasty (UKA) revision. Therefore, the purpose of this study was to evaluate the alterations of the lateral compartment congruence and joint space width (JSW) following medial UKA. MethodsRetrospectively, lateral compartment congruence and JSW were evaluated in 174 knees (74 females, 85 males, mean age 65.5years; SD±10.1) preoperatively and six weeks postoperatively, and compared to 41 healthy knees (26 men, 15 women, mean age 33.7years; SD±6.4). Congruence (CI) was calculated using validated software that evaluates the geometric relationship between surfaces and calculates a congruence index (CI). JSW was measured on three sides (inner, middle, outer) by subdividing the lateral compartment into four quarters. ResultsThe CI of the control group was 0.98 (SD±0.01). The preoperative CI was 0.88 (SD±0.01), which improved significantly to 0.93 (SD±0.03) postoperatively (p<0.001). In 82% of knees, CI improved after surgery, while in 18% it decreased. The preoperative significant JSW differences of the inner (p<0.001) and outer JSW (p<0.001) were absent postoperatively. ConclusionOur data suggests that a well-conducted medial UKA not only resurfaces the medial compartment but also improves congruence and restores the JSW of the lateral compartment.

Changes in joint space width during Kaltenborn traction according to traction grade in healthy adults.

[Purpose] The aim of this study was to analyze the joint space width of the humeral head and glenoid fossa during traction under 2 grade conditions (grade 2/grade 3). [Subjects and Methods] The subjects were 20 healthy male adults who had not experienced any shoulder injury. Three radiographs were obtained with the subjects in the supine position (resting, grades 2 and 3). The glenohumeral joint space was examined on radiography. Joint space width was measured by a radiologist at the points described by Petersson and Redlund-Johnell. A radiologist blinded to the variable “resting” or “traction” performed all radiographic measurements. The joint space widths were compared by using one-way repeated-measures analysis of variance. [Results] The results of this study indicated significant differences in the changes in joint space width according to traction grade. Compared to resting, grades 2 and 3 traction significantly increased joint space width. However, no significant difference in joint space width was found between grades 2 and 3 traction. [Conclusion] Although no significant differences were found between grades 2 and 3 traction during glenohumeral joint traction, the increase in joint space width between the glenoid fossa and humeral head was highest during grade 3 traction.

Early Anatomic Changes of the Ulnar Collateral Ligament Identified by Stress Ultrasound of the Elbow in Young Professional Baseball Pitchers

Background: Stress ultrasound (SUS) of the elbow has demonstrated changes in the anterior band of the ulnar collateral ligament (UCL) in professional baseball pitchers. However, there have been no reports documenting the chronological appearance of these changes. Purpose: To characterize the chronology of anatomic changes of the UCL in a cohort of young professional baseball pitchers. Study Design: Cross-sectional study; Level of evidence, 3. Methods: SUS of the elbow was performed on the dominant arm in 127 asymptomatic professional pitchers aged 17 to 21 years. UCL thickness was measured at rest. The width of the ulnohumeral joint was measured at 30° of elbow flexion, both at rest and with 150 N of valgus stress, using a standardized instrumented device. Any ligament heterogeneity and calcifications were documented. Players were divided into 3 groups based on the number of years of professional experience before the ultrasound examination: 0 years (n = 51), 1-2 years (n = 54), and 3-4 years (n = 22). Additionally, players were divided into 5 groups based on chronological age at the time of the first SUS examination: 17 years (n = 5), 18 years (n = 18), 19 years (n = 33), 20 years (n = 20), and 21 years (n = 51). Statistically significant differences between the groups were determined. Results: The mean UCL thickness was 5.85 ± 1.22 mm, 6.23 ± 1.32 mm, and 6.94 ± 2.12 mm in the players with 0, 1-2, and 3-4 years of professional experience, respectively. This difference was statistically significant overall (P = .024) as well as statistically significant between each consecutive group. There was no statistically significant difference in joint space width at rest or with applied stress between groups (P = .944). Additionally, there was no statistically significant difference in the presence of calcifications (27.5%, 27.8%, and 40.9%, respectively; P = .144) or heterogeneity (29.4%, 16.7%, and 40.9%, respectively; P = .502) as years of professional experience increased from 0 to 3-4 years. There were no significant differences in UCL thickness (P = .363), joint space width with stress (P = .648), or echotextural abnormalities based on chronological age (P = .871 [hypoechoic foci] and P = .520 [calcifications]). Conclusion: These findings suggest that an increase in UCL thickness may be one of the first changes to develop in young professional baseball pitchers.

Extremity cone-beam CT for evaluation of medial tibiofemoral osteoarthritis: Initial experience in imaging of the weight-bearing and non-weight-bearing knee

PurposeTo investigate differences in joint space width (JSW) and meniscal extrusion (ME) between non-weight bearing (NWB) and weight bearing (WB) examinations of knee joints with medial compartment osteoarthritis (OA) using a cone-beam CT (CBCT) extremity imaging system. Materials and methodsIn this IRB approved prospective study, informed consent was obtained for 17 patients symptomatic for OA (11 F,6M; 31–78 years, mean 56 years) and 18 asymptomatic controls (0 F,18M; 29–48 years, mean 38.5 years) enrolled for CBCT exams in NWB and WB positions. Three independent observers measured medial tibiofemoral JSW and ME. Measurements were compared between NWB and WB images using paired Wilcoxon signed-rank sum test. ResultsOA subjects exhibited a statistically significant reduction in JSW between NWB and WB scans (average JSWNWBOA=2.1mm and JSWWBOA=1.5mm, p=0.016) and increase in ME (average MENWBOA=6.9mm and MEWBOA=8.2mm, p=0.018)). For non-OA subjects, the change in JSW and ME between NWB and WB exams was reduced (average JSWNWBnonOA=3.7mm and JSWWBnonOA=3.4mm; average MENWBnonOA=2.6mm and MEWBnonOA=2.7mm) and was not statistically significant. Inter-observer agreement was evaluated using Bland–Altman limits of agreement, with good agreement for all measurements (correlation coefficient 0.89–0.98). ConclusionThe ability to conduct NWB and WB exams in CBCT with a dose profile that is favorable in comparison to multidetector CT (MDCT) and with image quality sufficient for morphological analysis of joint space narrowing and meniscal extrusion could provide a valuable tool for OA diagnosis and treatment assessment.

Relationship Between Isokinetic Strength and Tibiofemoral Joint Space Width Changes After Anterior Cruciate Ligament Reconstruction

Background: It has been hypothesized that quadriceps muscle weakness is directly associated with the onset and progression of posttraumatic osteoarthritis after anterior cruciate ligament (ACL) injury and reconstruction (ACLR). This relationship, however, has not been studied with a prospective approach that includes the use of tibiofemoral joint space width difference (JSW-D) measurements to characterize the onset of posttraumatic osteoarthritis before the clinical manifestation of the disease. Purpose: To assess the relationship between thigh muscle strength and JSW-D at presurgery baseline and at 1- and 4-year follow-up after ACLR compared with healthy, noninjured participants of similar sex, age, body mass index, and activity level. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 39 unilateral ACL-injured patients and 32 healthy controls were followed prospectively. During each follow-up, JSW, isokinetic knee strength, single-legged hop, and clinical- and patient-oriented outcomes were assessed. At final follow-up, ACL-injured participants who had JSW-D values (considered as the injured minus normal knee) that were less than the 95% confidence interval of controls were considered to be in the ACLR-narrow group, while those with JSW-D values that fell within the confidence intervals were in the ACLR-normal group. Relationships were evaluated between ACLR groups and controls via multilevel regression, as well as Kruskal-Wallis tests for between-group comparisons at 4-year follow-up. Results: At 4-year follow-up, 30 participants (79%) were in the ACLR-normal group and 8 (21%) were in the ACLR-narrow group. At baseline, the extension, flexion, and extension/flexion ratio strength values for both ACLR groups were significantly lower than those of controls (P ≤ .05), while the ACLR-narrow group had significantly lower extension strength at 60 and 180 deg/s (P = .04 and .03, respectively), as well as extension/flexion ratio at 60 deg/s (P = .04) in comparison with the ACL-normal group. At 4-year follow-up, 60 deg/s extension strength deficits persisted in the ACLR-narrow group compared with controls and ACLR-normal participants (P = .01 and .04, respectively). Flexion strength at 180 and 300 deg/s was also significantly lower in the ACLR-narrow group compared with ACLR-normal (P = .02 and .04, respectively), as was single-legged hop distance (P = .04). Conclusion: Strength deficits present within months after ACL injury and persist through 4 years after ACLR in participants with significantly narrowed JSW-D, compared with ACLR participants with normal JSW-D and controls. This study revealed a significant relationship between quadriceps strength loss that occurred soon after injury and JSW narrowing.

Evaluation of Joint Space Width and Narrowing After Isolated Partial Medial Meniscectomy for Degenerative Medial Meniscus Tears.

Background:Few studies have evaluated the effect of existing articular cartilage damage and sex on joint space measurements after isolated degenerative medial meniscus tears.Purpose:To determine what factors affected joint space width and narrowing in patients after removal of isolated degenerative medial meniscus tears.Study Design:Cohort study; Level of evidence, 2.Methods:A total of 62 patients (15 women and 47 men) with all ligaments intact, no previous surgery to either knee, and an isolated degenerative medial meniscus tear removed in 1 knee were examined. The mean age at examination was 58.2 years at a mean follow-up of 9.4 years (range, 4-20 years). Subjective results were obtained with the International Knee Documentation Committee (IKDC) knee survey. Radiographs were taken using 45° weightbearing posteroanterior views. Midpoint and perceived minimum joint space width of the medial and lateral compartments of both knees were measured to the nearest 0.1 mm by 2 observers at different times, and they were blinded as to the previous measurements (Pearson intra- and interclass correlations, >0.93). Joint space narrowing was found by calculating the difference in joint space width between knees. Percentage of normal joint space loss was calculated by dividing joint space narrowing by the joint space width in the contralateral knee. Other factors considered were patient sex and Outerbridge grading of articular cartilage.Results:Women had a mean 1.5 mm less normal joint space width than men in the involved and noninvolved knees (P < .01). Mean joint space narrowing was 0.7 mm for both measurements. The mean ± standard deviation narrowing was 0.4 ± 1.2 mm for patients with grade 0-2 damage and 1.1 ± 1.3 for patients with grade 3-4 damage (P = .04). Five women (33%) and 3 men (6%) had narrowing of >50% of the normal joint space as measured in the noninjured knee (P = .016). The mean IKDC total score was 66.1 points for women, which was statistically significantly lower than the mean of 82.7 points for men (P < .01).Conclusion:Patients undergoing partial medial meniscectomy have greater joint space narrowing and lower subjective scores after surgery if they also have existing Outerbridge grade 3-4 damage. Women have less normal joint space than men, and more women than men experience >50% joint space narrowing after surgery.

OP0035 Value of bilateral standing oblique radiographs (“FAUX profil de lequesne“) in the diagnosis of hip osteoarthritis

BackgroundMeasurement of joint space width (JSW) on antero-posterior (AP) radiograph of the pelvis is the reference imaging method for the diagnosis and follow-up of hip osteoarthritis (OA). However, the AP...

Relationship between isokinetic strength and tibiofemoral joint space width changes following ACL reconstruction

Purpose: Following anterior cruciate ligament (ACL) injury and reconstruction (ACL-R), quadriceps muscle weakness and low hamstring-to-quadriceps muscle strength ratios have been associated with post-traumatic osteoarthritis (PTOA) as well as primary OA. However, this relationship has not been examined using tibiofemoral joint space width difference (JSW-D) as a measurement of PTOA onset. JSW-D is a measurement technique that is sensitive to PTOA changes prior to the clinical manifestation of the disease. It is important to determine risk factors associated with the onset and progression of PTOA at the earliest time point in the disease process when intervention can alter the progression of the disease. Consequently, the focus of this study was to examine the relationship between isokinetic knee strength and JSW-D at one and four years post-ACL-R compared to a group of healthy, non-injured subjects of similar sex, age, BMI, and activity level. Methods: A secondary analysis of data collected during a longitudinal study of biomarkers of PTOA following ACL-R was utilized for this exploratory study. Entry criteria for injured subjects included: age at time of ACL-R = 14-55; BMI = 18.5-30; Tegner activity score > 4; < 2/3 meniscectomy; < grade IIIa articular cartilage lesions; no history of joint surgeries, knee injections, or other knee pathologies; no abnormal knee laxity or evidence of radiographic OA at baseline. Additional criteria for controls included: no knee pain/dysfunction, and normal clinical evaluation and baseline MRI. At 1- and 4-years post ACL-R, standing, bilateral metatarsal phalangeal (MTP) view knee x-rays were obtained for JSW assessment. Subjects were considered to have significant narrowing if their injured minus normal (contralateral) knee JSW difference (JSW-D) fell below the 95% confidence interval of controls. At the same time point, isokinetic knee strength was assessed at 60, 180, and 300 deg/sec, and normalized to body weight. Relationships between strength and JSW-D were evaluated between ACL subgroups (normal and narrowed) and controls using analysis of covariance adjusted for age, sex, BMI, and time since surgery. Post-hoc group comparisons were made using Fisher's LSD. Results: Of the 34 ACL-R patients included, 6 had significant JSW-D narrowing at 1-year follow-up, and 8 had narrowing at 4-year follow-up. The mean strength values for all ACL-R subjects (“normal” and “narrowed JSW-D” groups combined) were found to be significantly less than the control group at both time points. However, ACL-R subjects with narrowed JSW-D did not differ from normal JSW-D subjects (all p > 0.20) with one exception: extension at 60 degrees/second at four-year follow-up (p = 0.005). The pattern of knee extension strength at 60 deg/sec at 1-year follow-up was similar to changes observed at 4-year follow-up. Extension to flexion strength ratios were not found to have a significant association with JSW-D at any speed. Conclusions: Strength deficits present as early as one year following ACL-R and persist at 4-years post. In general, ACL-R group subjects were not found to have significantly different strength values within JSW subgroups. In contrast to previous studies, the current investigation did not reveal an association between PTOA and low extension to flexion strength ratios. It should be noted that no subjects in this study reported appreciable pain/dysfunction or reduced physical activity, which is indicative of the clinical manifestation of OA. However, subjects with narrowed JSW-D had significantly lower extension strength at 60 degrees/second than controls and injured subjects with normal JSW-D. It may be that individuals that loose a significant amount of knee extension strength are at greater risk for tibiofemoral JSW narrowing following ACL trauma.

Assessment of Early Tibiofemoral Joint Space Width Changes After Anterior Cruciate Ligament Injury and Reconstruction

Background: Progression of primary knee osteoarthritis (OA) is often quantified by measuring structural alterations of the joint such as those in tibiofemoral joint space width (JSW) over time. Limited information is available regarding changes that occur during the onset and progression of posttraumatic OA (PTOA) that are often associated with anterior cruciate ligament (ACL) injury. Furthermore, there is a paucity of information regarding JSW changes in healthy patients, making JSW interpretation challenging during early PTOA progression. Purpose: To evaluate tibiofemoral JSW after ACL injury, ACL reconstruction, and rehabilitation compared with healthy, matched controls. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 39 ACL-injured patients and 32 matched controls were evaluated. Injured patients were assessed at presurgical baseline and after ACL reconstruction (mean follow-up, 46 months), as were controls. Bilateral, standing, fluoroscopy-assisted, and posterior-anterior metatarsal-phalangeal view knee radiographs were obtained at each visit and JSW was measured. Results: The JSW differences between knees in control patients were not significantly different and did not change over time. Baseline JSW differences in the ACL group were significantly different than in controls. Three patients (7.9% of total) had an increased JSW difference, and 1 patient (2.6%) had a decreased medial JSW difference. In the lateral compartment, 6 patients (15.8%) had a decreased JSW difference. At follow-up, 2 patients in the ACL group (5%) had a decreased medial JSW difference, and 3 (7.9%) had a significantly increased difference in relation to controls. Lateral compartment analyses revealed 7 (18.4%) patients with a significantly decreased JSW difference and no patients with an increased difference compared with controls. Conclusion: One third of ACL-injured knees underwent significant JSW change soon after injury; consequently, evaluation of within-knee JSW changes over time in ACL-injured patients may not be appropriate with a study based on case-control analysis. The JSWs in the healthy knee of ACL-injured patients do not change over time, allowing this knee to be used as a control for the injured knee. This is important when evaluating the earliest stages of PTOA after ACL injury, when patients are asymptomatic and intervention may be most beneficial.

Relationship Between Markers of Type II Collagen Metabolism and Tibiofemoral Joint Space Width Changes After ACL Injury and Reconstruction

Background: Those who suffer anterior cruciate ligament (ACL) disruptions are at increased risk of experiencing posttraumatic osteoarthritis (OA); however, by the time they become symptomatic, irreversible damage has likely occurred. Little is known regarding the physiological changes in articular cartilage that occur after an ACL injury and the onset of OA. Purpose: To assess whether patient, functional, and clinical outcomes and type II collagen metabolism are associated with abnormal tibiofemoral joint space width (JSW) 4 years after injury and reconstruction. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 35 ACL-injured patients who underwent ACL reconstruction were enrolled soon after injury, as were 32 matched controls. At baseline and 1- and 4-year follow-ups, patient-oriented subjective and objective outcomes and markers of type II collagen metabolism (considered as the ratio of cleavage to synthesis of type II collagen) were evaluated, as were radiographic measurements of JSW changes about the medial and lateral compartments of the knee. ACL-injured patients were divided into normal and abnormal JSW groups. Results: Both ACL-injured groups (normal and abnormal JSW) had an increased ratio of collagen type I and II cleavage product (uC1,2C) to serum procollagen II C-propeptide (sCPII) compared with controls at 1- and 4-year follow-ups. Patients in the ACL group with an abnormal JSW difference had significantly increased cleavage-to-synthesis ratios of type II collagen (assessed as C-terminal cross-linked telopeptide of type II collagen [uCTX-II]/sCPII ratio) compared with controls at 4-year follow-up. ACL-injured patients with an abnormal JSW difference had significantly increased pain and decreased quality of life (Knee Injury and Osteoarthritis Outcome Score [KOOS]) scores than did ACL-injured patients with a normal JSW difference. Conclusion: ACL-injured patients with an abnormal tibiofemoral JSW had diminished quality of life, increased pain, and increased type II collagen uCTX-II/sCPII ratios compared with healthy controls. These changes occurred over an interval shortly after injury in patients who were fully functional and who had normal clinical examination findings, no pivoting/giving-way episodes, and no decrease in activity level.

9 RELATIONSHIP BETWEEN ARTHROSCOPIC FINDINGS AT THE TIME OF ACL RECONSTRUCTION AND TIBIOFEMORAL JOINT SPACE WIDTH

Purpose: Little is known about the initial onset and early progression of post-traumatic OA (PTOA) following severe knee trauma such as that associated with anterior cruciate ligament (ACL) disruption. The purpose of this investigation was to study subjects following ACL injury with and without associated injuries to the cartilages (meniscal and articular cartilages) and determine the relationship between these concomitant injuries and tibiofemoral joint space width (JSW) compared to healthy, matched controls at 3–4 year follow-up. Methods: This investigation was designed as a prospective cohort study with a nested case-control analysis. Thirty-eight ACL-injured (20 women) and 32 healthy control subjects (18 women) matched for age, sex, race, BMI, and activity level were evaluated and followed over 3–4 years. Entry criteria for ACL-R subjects included: Age 14–55 yrs; BMI = 18.5–30, Tegner activity score >4; no relevant knee pathologies other than what was produced by the index injury; normal anatomic alignment; less than 2/3 menisectomy; and Gr IIIa articular cartilage lesions or less. All reconstructions occurred within 6 months of injury, and all subjects participated in a standardized rehabilitation program. Similar entry criteria were utilized for controls, with the exception of: no history of knee pain or dysfunction; no abnormal findings with clinical knee examination; and no abnormal findings on baseline MRI. Articular cartilage and meniscus lesions were identified via arthroscopic visualization at the time of ACL-R and graded by an experienced orthopedic surgeon. This information was recorded on the 2000 International Knee Documentation Committee (IKDC) Surgical Documentation Form, and included characterization of meniscus and articular cartilage lesion location, size, and severity. Bilateral, weight bearing tibiofemoral radiographs were obtained at baseline and 3–4 year follow-up intervals and JSW assessed using previously validated techniques. Subjects were considered to have significant JSW differences of their injured knee if the injured minus normal (contralateral) knee difference fell outside the calculated 95% confidence interval (CI) of bilateral differences measured in controls. Logistic regression (controlled for subject age, sex, BMI, and time between injury and ACL-R) was used for group comparisons and calculation of corresponding odds ratios. Results: Statistical analyses revealed two distinct groupings of JSW differences for the ACL-R subjects. Those with a grade IIb articular cartilage lesion or less and “intact” menisci in both the medial and lateral compartments (the “low-risk” group); or those with grade IIIa femoral articular cartilage lesions and/or menisectomy in either compartment (“high-risk” group). The low risk group was comprised of 25 subjects, and 72% (18/25) of these individuals had JSW values that fell within the normal 95% CI of control values. The high-risk group was comprised of 13 subjects, with only 38% (5/13) having normal JSW at follow-up. Subjects in the high risk group were significantly more likely to have JSW difference values that fell outside the 95% CI of controls in comparison to those in the low risk group (OR: 4.11; 95% CI: 1.01 to 39.55; p = 0.05). Conclusions: Suffering ACL injury in combination with either a grade IIIa articular cartilage lesion, or meniscus injury requiring surgical resection resulted in ACL-R subjects that were more than 4 times more likely to display abnormal JSW changes in comparison to ACL-R subjects without these concomitant injuries at 3–4 year follow-up. These dramatic changes occurred over a relatively short time interval following the injury and reconstruction in subjects with normal knee function and no symptoms of OA and this demonstrates the importance of these articular structures on what appears to be some of earliest changes associated with the initial onset of PTOA.

Direct magnetic resonance arthrography of the wrist with axial traction: A feasibility study to assess joint cartilage

To assess the impact of axial traction during acquisition of direct magnetic resonance (MR) arthrography of the wrist with regard to joint space width and amount of contrast material between the opposing cartilage surfaces. Fifteen consecutive patients (12 male, mean age 38.1 years) were included in this Institutional Review Board-approved prospective study. Three-compartment wrist MR arthrographies were performed between October and December 2009 on a 3 T unit using a fat-suppressed T1-weighted isotropic high-resolution volumetric interpolated breathhold examination (VIBE) sequence in the coronal plane, with and without axial traction (3 kg). Two radiologists measured radiocarpal (radioscaphoid, radiolunate) and midcarpal (lunocapitate, hamatolunate) joint space widths, with and without traction, and assessed the amount of contrast material between the opposing cartilage surfaces using a three-point scale: 0 = absence, 1 = partial, 2 = complete. With traction, joint space width increased significantly at the radioscaphoid (Δ = 0.78 mm, P < 0.01), radiolunate (Δ = 0.18 mm, P < 0.01), and lunocapitate (Δ = 0.45 mm, P < 0.01) spaces, and both observers detected significantly more contrast material between the cartilage surfaces. At the hamatolunate space, the differences in joint space width (Δ = 0.14 mm, P = 0.54) and amount of contrast material were not significant. Direct wrist MR arthrography with axial traction of 3 kg increases joint space width at the radiocarpal and lunocapitate spaces, and prompts better coverage of the articular cartilage by the contrast material.

Comparison of cartilage thickness with radiologic grade of knee osteoarthritis

To compare joint space width (JSW) measurements obtained from magnetic resonance imaging (MRI) with a semi-automated computer algorithm to the Kellgren and Lawrence grading of osteoarthritis (OA). Three hundred and six patients (234 female, 72 male) with a mean age of 56.7 years (range 31-81 years) underwent MRI of their knees with a fast oblique spiral spoiled gradient (SPGR) sequence. A board-certified musculoskeletal radiologist graded the OA of all the patients in accordance with the Kellgren and Lawrence OA scale. A previously validated computer algorithm was used to determine the minimum JSW for both the tibiofemoral joint and the patellofemoral joint. An analysis of variance (ANOVA) with the Student-Newman-Kuels post-hoc test was used to determine if there were differences in JSW as a function of OA grade. The radiologic grade of OA was inversely associated with the JSW. In the medial compartment the JSW did not change significantly between grade 1 and grade 2, but there was a significant decrease in JSW between grade 0 (normal) and grade 1 and for each OA grade above grade 2. In the lateral compartment no statistical differences were found till grade 2, while grade 3 was found to be statistically different from the previous one. The number of patients with a grade 4 patellofemoral OA was too low for the statistical significance to be assessed. In the patellofemoral joint the JSW did not change significantly until grade 2, while a statistically significant reduction was found for both grade 3 and grade 4. This study showed that an inverse non-linear relationship exists between radiologic grade and JSW. The relationship differs for the tibiofemoral and the patellofemoral joint.

Measurement of joint space width in hip osteoarthritis: influence of joint positioning and radiographic procedure.

We assessed the influence of patient positioning and radiographic procedure, and defined a smallest detectable difference (SDD) in hip osteoarthritis (OA). OA hip patients each had a standardized pelvic radiograph and, 5 min later, a modified pelvic radiograph with the feet internally rotated 5 degrees (part 1 of the study), the X-ray beam centred on the umbilicus (part 2), or another standardized pelvic radiograph (part 3). Corresponding mean differences in joint space width (JSW) measurements (limits of agreement) between views were +0.03 (-0.53 to +0.59), -0.31 (-1.15 to +0.53) and -0.02 (-0.48 to +0.44) mm. The two views differed significantly in mean JSW in part 2 of the study (P=1.6x10(-4)), but not in part 1 (P=0.375) and part 3 (P=0.580). The SDD estimate was 0.46 mm. Modifying the X-ray beam and foot rotation increases variability in JSW measurements. Use of urograms to evaluate radiological progression should be avoided. A change greater than 0.46 mm could define radiological hip OA progression.

Pattern of advancement in the zone of calcified cartilage detected in hand osteoarthritis

Using high definition macroradiography the pattern of advancement in the zone of calcified cartilage (termed a ZCC step) was detected in osteoarthritic hand joints of patients and compared to the joint space width (JSW) measurement. X5 macroradiographs were obtained of the osteoarthritic hands of 44 patients at baseline and at 18 months. The incidence of ZCC steps, identified as an advancement in the mineralized cartilage front into articular cartilage, was assessed at each articular surface. JSW was measured and was used to determine the difference in JSW between hands and groups of joints with and without ZCC steps at both X-ray visits. ZCC steps were found at the convex articular surfaces in only 42 (48%) hand joints in 28 (64%) patients. Here, ZCC steps were present in 36 joints in the non-dominant hand, compared with 30 joints in the dominant hand. In the former, they were present in 22 DIP, six PIP and eight MCP joints and in 12 DIP, eight PIP and 10 MCP joints in the dominant hand. By 18 months, new ZCC steps had formed in 15 hands with and 17 hands without previous ZCC steps. At both X-ray visits no statistically significant difference in JSW was found between the hands and joint groups with and without ZCC steps. In patients with ZCC steps, the pattern of distribution in the hand appeared to be related to that due to vascular changes, such as hyperlipidaemia, rather than to that associated with mechanical forces.

Advancement in the zone of calcified cartilage in osteoarthritic hands of patients detected by high definition macroradiography

Objective High definition macroradiography permits the advancement in the zone of calcified cartilage (described as a ZCC step) to be detected in osteoarthritic (OA) hand joints of patients. The pattern of their incidence and distribution was determined and compared to the joint space width (JSW) measurement.Design Macroradiographs, ×5 magnification, were obtained of the OA hands of 44 patients at baseline and at 18 months. The incidence of ZCC steps, identified as an advancement in the mineralized cartilage front into articular cartilage, was assessed at each articular surface. JSW was measured and was used to determine the difference in JSW between hands and groups of joints with and without ZCC steps at both X-ray visits.Results ZCC steps were only found at the convex articular surfaces in 42 (48%) of hand joints in 28 (64%) patients. Here, ZCC steps were present in 36 joints in the non-dominant hand compared to 30 joints in the dominant hand. In the former, they were present in 22 DIP, six PIP and eight MCP joints and in 12 DIP, 8 PIP and 10 MCP joints in the dominant hand. By 18 months new ZCC steps had formed in 15 hands with and 17 hands without previous ZCC steps. At both X-ray visits no statistically significant difference in JSW was found between the hands and joint groups with and without ZCC steps.Conclusion Although ZCC steps and JSW loss were greater at the PIP joints, supporting a mechanical hypothesis for ZCC formation, their presence in joints, where JSW was larger, and their greater incidence in the non-dominant PIP joints, suggest that factors associated with vascular changes, related to subchondral bone remodeling, are responsible.{copy}