Association between varus alignment and post-traumatic osteoarthritis after anterior cruciate ligament injury.

PURPOSE: To investigate the association between varus alignment and post-traumatic osteoarthritis (OA) after an anterior cruciate ligament (ACL) injury. METHODS: One hundred subjects with an acute complete ACL tear were followed for 15 years. Anterior-posterior radiographs of the tibiofemoral joint were obtained with a knee flexion of 20°, and the patellofemoral joint was examined with skyline view at 50° knee flexion. Joint space narrowing and osteophytes were graded in the tibiofemoral and patellofemoral joints in the injured (ACL) and uninjured knee according to the radiographic atlas of the Osteoarthritis Research Society International. The alignment of the uninjured, contralateral knee was measured at follow-up, using full-limb radiographs of leg with the knee in full extension. Alignment was expressed as the hip-knee-ankle (HKA) angle. Alignment was defined as valgus (HKA ≤178°), neutral (179°-181°) or varus (≥182°). RESULTS: Data from 68 subjects were included in the analysis. Varus alignment of the uninjured knee at follow-up appeared to be associated with OA of the injured knee 15 years after an ACL injury (odds ratio (95% confidence interval) 3.9 (1.0-15.8, p = 0.052)). CONCLUSIONS: Varus alignment of the uninjured knee at follow-up may be associated with OA of the injured knee 15 years after an ACL injury. LEVEL OF EVIDENCE: II.

Differences in the radiological characteristics between post-traumatic and non-traumatic knee osteoarthritis.

Osteoarthritis (OA) of the knee can be defined as primary (non-traumatic) or secondary (post-traumatic). Both non-traumatic OA and post-traumatic OA have been described predominantly in the medial compartment of the knee. The objective of this study was to compare the location of structural radiographic changes in non-traumatic OA and post-traumatic OA. A non-traumatic cohort, consisting of 155 patients suffering from chronic knee pain without known major injuries, was compared with a post-traumatic cohort, consisting of 176 patients, all of whom had sustained an anterior cruciate ligament injury while playing soccer. A standardized weight-bearing knee radiography of the tibiofemoral joint was performed. Joint space narrowing (JSN) and osteophytes were graded according to the radiographic atlas of the Osteoarthritis Research Society International. JSN and osteophytes were located predominantly in the medial compartment in the non-traumatic cohort. In the post-traumatic cohort, structural changes were evenly distributed between the lateral and the medial compartments. We were thus able to demonstrate radiological differences between post-traumatic and non-traumatic OA.

The acutely ACL injured knee assessed by MRI: are large volume traumatic bone marrow lesions a sign of severe compression injury?

OBJECTIVES: To map by magnetic resonance imaging (MRI) and quantitative MRI (qMRI) concomitant fractures and meniscal injuries, and location and volume of traumatic bone marrow lesions (BMLs) in the acutely anterior cruciate ligament (ACL) injured knee. To relate BML location and volume to cortical depression fractures, meniscal injuries and patient characteristics. METHODS: One hundred and twenty-one subjects (26% women, mean age 26 years) with an ACL rupture to a previously un-injured knee were studied using a 1.5T MR imager within 3 weeks from trauma. Meniscal injuries and fractures were classified by type, size and location. BML location and volume were quantified using a multi-spectral image data set analyzed by computer software, edited by an expert radiologist. RESULTS: Fractures were found in 73 (60%) knees. In 67 (92%) of these knees at least one cortical depression fracture was found. Uni-compartmental meniscal tears were found in 44 (36%) subjects and bi-compartmental in 24 (20%). One hundred and nineteen (98%) knees had at least one BML, all but four (97%) located in the lateral compartment. Knees with a cortical depression fracture had larger BML volumes (P<0.001) than knees without a cortical depression fracture, but no associations were found between meniscal tears and BML volume or fractures. Older age at injury was associated with smaller BML volumes (P<0.01). CONCLUSION: A majority of the ACL injured knees had a cortical depression fracture, which was associated with larger BML volumes. This indicates strong compressive forces to the articular surface and cartilage at the time of injury, which may constitute an additional risk factor for later knee osteoarthritis development.

Radiography and bone scintigraphy in osteoarthritis of the knee--comparison with MR imaging.

PURPOSE: Osteoarthritis (OA) is a multifactorial process affecting cartilage and subchondral bone. Traditionally, plain radiographs and eventually bone scintigraphy are used to establish the diagnosis, whereas MR imaging, as a sensitive instrument for early diagnosis, is less commonly used. Therefore, these methods have been compared in the format of a prospective study of knee OA. MATERIAL AND METHODS: Individuals aged 35-54 years with chronic knee pain have been identified. The prevalence of chronic knee pain was 15% (279/2,000). Within this group, both knees in 61 randomly chosen persons were examined with plain weight-bearing radiographs of the tibiofemoral joint (TFJ), standing axial radiographs of the patellofemoral joint (PFJ), and with bone scintigraphy. One knee (the most painful at inclusion in the study) in each person was examined with MR imaging on a 1.0 T imager. RESULTS AND CONCLUSIONS: Assessment of the minimal joint space (MJS) width in the p.a. view of the TFJ in weight-bearing examinations should be performed with equal weight on both legs and in semiflexion. The p.a. view of the TFJ and the axial view of the PFJ, as well as the MJS measurements in these views, were reproducible. MJS of 3 mm in the TFJ and MJS of 5 mm in the PFJ are limits in diagnosing joint-space narrowing (JSN) in the TFJ and the PFJ, respectively. There was a high prevalence of meniscal abnormalities within the narrowed compartments of the TFJ when compared with those that were not narrowed. With the presence of marginal osteophytes in the TFJ, there was a high prevalence of MR-detected cartilage defects in the same joints whether JSN (MJS < 3 mm) was present or not. No such relationship, independent of MJS, was found between marginal osteophytes and cartilage defects in the PFJ. The agreement between increased bone uptake and MR-detected subchondral lesion (increased signal in the STIR sequence) was good. The agreement between increased bone uptake and MR-detected osteophytes or cartilage defects was in general poor. Conventional radiography is inexpensive and readily available. With the increased knowledge about interpreting weight-bearing p.a. radiographs of the TFJ and standing axial radiographs of the PFJ, these examinations will, even in the future, be a valuable and competitive technique compared with a more expensive and sophisticated method such as MR imaging, when evaluating knee pain. Further studies have to be performed to evaluate whether MR imaging has the same ability as bone scintigraphy to predict the progression of the OA process in the knee joint.

Radiography in osteoarthritis of the knee.

Osteoarthritis (OA) is a multifactorial process affecting cartilage and subchondral bone. Conventional radiographs are inexpensive and readily available. The increased knowledge with regard to interpreting weightbearing radiographs of the tibiofemoral joint and axial radiographs of the patellofemoral joint will enable these examinations to remain competitive techniques compared with more expensive and sophisticated methods, such as MR imaging, when investigating knee pain to establish the diagnosis and the severity of OA.

Total knee replacement in juvenile chronic arthritis.

Twelve patients with juvenile chronic arthritis (JCA) underwent 18 primary knee replacements during 1975-81. Eleven patients were followed for an average of six (3-9) years. Mean age at operation was 25 (18-32) years. Indications for surgery were pain and limitation of motion. Four knee joints were revised, one of them three times, due to malposition and/or mechanical loosening of the prosthetic components. At follow-up, all patients except one were satisfied with the knee replacement. All patients except one were ambulatory. Functional capacity was improved in 8 patients. The arc of motion was increased by a mean of 17 degrees. The radiographs at follow-up showed an average hip-knee-ankle (HKA) angle of 182 (173-193) degrees. In eight knee joints the tibial and/or femoral component showed a radiolucent zone at the bone-cement interface exceeding 2 mm and in four of these joints there were signs of prosthetic migration. To aid in the choice of an appropriate prosthesis for the juvenile arthritic joint, standardized measurements of the radiographic dimensions of the knee joint were made. Because of the high rate of revisions during the short observation period and the potential failure rate indicated by the radiographs at follow-up, we maintain a cautious attitude towards knee replacement in patients with JCA.

Seventy-four Attenborough knee replacements for rheumatoid arthritis. A clinical and radiographic study.

Seventy-four Attenborough total knee replacements in patients with severe classical rheumatoid arthritis were followed for 2-5 years. The preoperative radiograms were evaluated according to two different scoring systems. At follow-up, radiographic whole leg examinations were performed. Mean malalignment was 7 degrees. The overall results were not encouraging with definite failure in eight knees and probable failure in another 21 knees. Failure was significantly correlated with postoperative malalignment.

Correlation between radiographically diagnosed osteophytes and magnetic resonance detected cartilage defects in the patellofemoral joint.

OBJECTIVE: To assess the correlation between radiographically diagnosed osteophytes in the axial and lateral view of the patellofemoral joint (PFJ) and (1) magnetic resonance (MR) detected cartilage defects in the same joint and (2) knee pain. METHODS: Fifty-seven people with chronic knee pain, (aged 41-58 years, mean 50 years) were examined with axial and lateral radiograms when standing of the right and the left PFJ. The presence and grade of osteophytes was assessed. On the same day, a MR examination was performed of the signal knee with proton density and T2 weighted turbo spin-echo sequences in the sagittal and axial view on a 1.0 T imager. Cartilage defects in the PFJ were noted. The subjects were questioned for current knee pain for each knee. RESULTS: Osteophytes at the PFJ had a specificity varying between 59 and 100% and a positive predictive value between 74 and 100% for MR detected cartilage defects. The corresponding values for osteophytes at the lateral aspect of the femoral trochlea were both 100%. In PFJ with narrowing (< 5 mm) osteophytes had a sensitivity and a positive predictive value of 90 and 95% respectively for MR detected cartilage defects, while in PFJ with non-narrowing (> or = 5 mm) the corresponding values were 75 and 65% and the specificity was 50%. A correlation (p < 0.05) between osteophytes at the inferior pole of the patella and knee pain was found. CONCLUSIONS: Osteophytes at the PFJ are associated with MR detected cartilage defects in the same joint. The relation was strong for osteophytes at the lateral femoral trochlea and in the PFJ with narrowing (< 5 mm), but weak in the PFJ with non-narrowing (> or = 5 mm).

Correlation between radiographically diagnosed osteophytes and magnetic resonance detected cartilage defects in the tibiofemoral joint.

OBJECTIVE: To assess the correlation between the presence of radiographically diagnosed osteophytes in the tibiofemoral joint (TFJ) and (1) magnetic resonance (MR) detected cartilage defects and meniscal lesions in the same joint and (2) knee pain. METHODS: Fifty-nine people, 29 men and 30 women, with chronic knee pain (aged 41-58 years, mean 50 years) were examined with posteroanterior weightbearing radiograms in semiflexion of both TFJ. The presence and grade of marginal and central osteophytes were assessed. On the same day, an MR examination was performed of the signal knee with proton density and T2 weighted turbo spin-echo sequences on a 1.0 T imager. Cartilage defects and meniscal abnormalities in the TFJ were noted. The subjects were questioned for current knee pain for each knee. RESULTS: Marginal osteophytes had a sensitivity of 77%, specificity of 83%, and positive predictive value of 87% for MR detected cartilage defects in the TFJ and a sensitivity of 71%, specificity of 68%, and positive predictive value of 71% for meniscal abnormalities. A correlation (p < 0.05) between osteophytes at the medial tibial condyle and knee pain was found. CONCLUSIONS: With the presence of marginal osteophytes in the TFJ there is a high prevalence of MR detected cartilage defects in the same joint whether joint space narrowing (< 3 mm) is present or not.

Joint-space width in the weight-bearing radiogram of the tibiofemoral joint. Should the patient stand on one leg or two?

PURPOSE: The aim of the study was to compare the minimal joint-space (MJS) width of the tibiofemoral joint (TFJ) in weight-bearing radiograms with the patient in two different positions. MATERIAL AND METHODS: From a study of 54 patients with chronic knee pain (aged 42-59 years, mean 52 years), we selected 21 consecutive patients for this study. In these 21 patients, both knees were examined by means of p.a. weight-bearing radiograms in semiflexion with fluoroscopic guidance. The patient stood with the weight: 1) almost entirely on the examined leg; and 2) equally distributed on both legs. The MJS was measured with a scale loupe in tenths of a millimeter in the medial and lateral compartments of the TFJ. RESULTS: With the patient standing on one leg, the MJS was 0.18 mm wider (p<0.006) in the medial compartment and 0.18 mm narrower (p<0.029) in the lateral compartment as compared to standing on both legs. CONCLUSION: With the technique used, the assessment of the MJS width in the p.a. view of the TFJ in weight-bearing examinations should be performed with equal weight on both legs. Standing on only the examined leg might be an option in cases of suspected narrowing in the lateral compartment.

Use of a guide instrument for compartmental knee arthroplasty.

To improve the positioning of the tibial component in compartmental knee arthroplasty a guide instrument was introduced. With the guide instrument the position in the frontal plane significantly improved from a mean medial slope of 10 degrees to 2 degrees. In the sagittal plane the change from a mean posterior slope of 5 degrees to 3 degrees was insignificant. The mean value for the Hip-Knee-Ankle angle (HKA) (ideal 180 degrees) was 186 degrees after "free-hand" operation and 183 degrees with the modified operative technique. Thus, it is possible with the aid of a guide instrument to improve the precision in compartmental knee arthroplasty.

Revision knee arthroplasty in rheumatoid arthritis.

Seventy-six revised total knee arthroplasties (TKAs) performed for mechanical, nonseptic failure of the primary arthroplasty in 62 rheumatoid arthritis patients were investigated. The revisions were performed with McIntosh, Marmor, Attenborough, Guepar, and various types of tricompartmental prostheses. Twenty-one of the 76 revisions subsequently failed. Fifteen were mechanical failures and six were deep infections. Thirteen of the 21 failures were treated with another arthroplasty, six with arthrodesis, and two with antibiotics only. After an average of 60 months, 48 of the surviving arthroplasties were examined clinically and roentgenographically. At follow-up examination, eight were clinical failures. One-half of the McIntosh and Marmor arthroplasties and one-third of the Attenborough and Guepar arthroplasties, altogether 17 cases, showed signs of potential roentgenographic failure. The majority of the revised TKAs classified as roentgenographic failures were clinically successful or acceptable. Revision of TKAs in noninfected rheumatoid patients can be performed with acceptable clinical results but with a significantly higher failure rate than after primary procedures.

Distribution of MR-detected cartilage defects of the patellofemoral joint in chronic knee pain.

OBJECTIVES: The aim of the study was to detect cartilage defects and determine the center of these defects in MR imaging of the patellofemoral joint (PFJ) in middle-aged people with chronic knee pain. DESIGN: In the format of a prospective study of early osteoarthritis (OA), this cross-sectional study of the signal knee (the most painful one at inclusion in the study in 1990) in 59 individuals, 30 women and 29 men (aged 41-58 years, mean 50 years) with chronic knee pain, with or without radiographically determined knee OA, was examined using MR imaging on a 1.0 T imager. Cartilage defects and the center of these defects in the PFJ were recorded. RESULTS: Cartilage defects were found more often in the patella (40 knees) than in the femoral trochlea (23 knees) (P<0.001) and were unevenly distributed in the patella (P<0.001), with most cartilage defects in the mid-patella. CONCLUSIONS: Since cartilage defects occur more commonly in the mid-patella, radiographs obtained with a knee flexion of approximately 45 degrees may be more accurate to show cartilage defects of early OA of the PFJ than views with another knee flexion.

Magnetic resonance imaging of the knee in chronic knee pain. A 2-year follow-up.

OBJECTIVE: The aim of the study was to evaluate the change over time of cartilage defects, subchondral lesions and meniscal abnormalities of the knee using magnetic resonance (MR) imaging with a 2-year interval in patients with chronic knee pain. DESIGN: In the format of a prospective study of early osteoarthritis (OA), the signal knee (most painful at the inclusion in the study 1990) in 47 individuals, 25 women and 22 men (aged 41-57 years, median 50), with chronic knee pain, with or without radiographically determined knee OA, were examined using MR imaging on a 1.0 T imager with a 2-year interval (median 25 months, range 21-30). Cartilage defects, subchondral lesions and meniscal abnormalities were recorded and compared in blind between the examinations. RESULTS: Five new cartilage defects and eight subchondral lesions appeared during the 2-year interval. Seven defects and seven subchondral lesions disappeared during the same time. Thirty-two out of 93 cartilage defects (34%) and 19 out of 32 subchondral lesions (59%) displayed an increase or a decrease in size over time. A meniscal abnormality appeared in three locations, and disappeared in none. In 14 out of 54 locations (26%) with a meniscal abnormality an increase or a decrease of the abnormality was recorded over time and no abnormality decreased. CONCLUSIONS: After the 2 years of observation it was possible to register, using MR imaging, the appearance, increase, decrease and disappearance of cartilage defects, subchondral lesions and meniscal abnormalities in middle-aged people with chronic knee pain. This has to be considered in studies of the natural course of knee OA as well as in studies of the intraarticular effect of pharmacological treatment aiming at cartilage repair or protection.

Radiographic osteoarthritis of the knee classified by the Ahlbäck and Kellgren & Lawrence systems for the tibiofemoral joint in people aged 35-54 years with chronic knee pain.

OBJECTIVES: To determine the prevalence of tibiofemoral radiographic knee osteoarthritis (OA) in people aged 35-54 years associated with chronic (> 3 months) knee pain using two different radiographic grading systems. METHODS: Population based postal survey in a random sample of inhabitants in a district in southern Sweden followed by clinical examination and plain posteroanterior, weight bearing radiographical examination. The Ahlbäck criteria (focusing on joint space narrowing) and the Kellgren & Lawrence classification for knee OA were used for diagnosing tibiofemoral OA. RESULTS: A questionnaire was sent to 2000 randomly selected people aged 35-54 years. The response rate was 92.6%. Fifteen per cent of these people reported chronic knee pain. This group (n = 279) was offered a clinical and radiographic examination of the knee joint and 204 persons agreed to participate. According to the Kellgren & Lawrence classification 28 subjects had OA of the knee grade 2 or more and 16 grade 3 or more. Radiographically detected OA of the knee according to Ahlbäck was found in 20 cases. The minimum prevalence of radiological tibiofemoral knee OA with knee pain was thus 1.5% for Kellgren & Lawrence grade 2 or more, 0.9% for grade 3 or more, and 1.1% according to the Ahlbäck classification. The agreement between the Kellgren & Lawrence grades 2-3 versus Ahlbäck grade I as well as grade 3-4 versus Ahlbäck grade I-II was good (kappa 0.76 and 0.78 respectively). CONCLUSION: The prevalence of radiographic tibiofemoral OA combined with chronic knee pain in people aged 35-54 years was around 1% as estimated by either the Kellgren & Lawrence or the Ahlbäck classifications systems. Prospective follow up of this cohort should elucidate the significance of knee pain as a sign of developing OA.

Changes in cartilage and bone metabolism identified by serum markers in early osteoarthritis of the knee joint.

Serum concentrations of two extracellular matrix molecules were determined over a 3 yr period in individuals with chronic knee pain to investigate whether sequential serum measurements of cartilage- and bone-derived molecular fragments reflect early stages of osteoarthritis (OA) of the knee joints. Thirty-eight individuals with chronic knee pain (> 3 months at inclusion) with or without radiographic evidence of knee joint OA at the 3 yr follow-up radiographic examination were studied. Serum concentrations of cartilage oligomeric matrix protein (COMP) and bone sialoprotein (BSP) increased significantly (P < 0.001) in the 23 individuals with radiographic OA at follow-up, while remaining unchanged in the 15 individuals with normal radiographs at follow-up. The baseline concentrations of the two variables did not differ between the groups. These findings suggest that pathological processes in cartilage and subchondral bone coincide in OA, and appear to be reflected by circulating levels of macromolecules released from cartilage and bone. Changes in serum levels of COMP and BSP are potential tools in studies of knee joint OA in subjects with chronic knee pain.

Gadolinium-DTPA-enhanced MR imaging in asymptomatic knees.

PURPOSE: To evaluate the occurrence and extent of Gd-DTPA-enhanced synovial structures in asymptomatic knee joints of middle-aged healthy individuals. MATERIAL AND METHODS: MR imaging of the knee joint was performed in 10 healthy subjects aged 40-61 years. The study included a sagittal T1-weighted SE sequence before and after i.v. injection of 0.1 mmol Gd-DTPA/kg b.w. RESULTS: Contrast-enhanced synovial structures were found in all knees. The extent of the synovial structures was usually not uniform within the examined joint. In the intercondylar fossa, the thickness of synovial structures was more often pronounced. In the suprapatellar recess, synovial thickness was constant and minimal. CONCLUSION: The presence and the varying extent and thickness of synovial structures in asymptomatic knees in middle-aged individuals must be considered in the evaluation of early and mild synovitis of the knee joint with Gd-enhanced MR imaging in this age group.

Joint space width of the tibiofemoral and of the patellofemoral joint in chronic knee pain with or without radiographic osteoarthritis: a 2-year follow-up.

OBJECTIVES: To assess the interval change of the minimal joint space width (MJS) in radiographs of the tibiofemoral (TF) joint and of the patellofemoral (PF) joint with a 2-year follow-up in middle-aged people with longstanding knee pain with or without radiographic osteoarthritis (OA) and to study the precision of the MJS measurements. DESIGN: In the format of a prospective study of early OA the signal knee in 55 people, 28 men and 27 women (aged 41-57 years, median 50), with chronic knee pain at inclusion was examined with a 2-year interval (median 25 months, range 21-30). The MJS of the TF joint was measured using a flexed PA view in weightbearing and the MJS of the PF joint using an axial view in standing. RESULTS: The MJS of the TF joint decreased medially by 0.056+/-0.44mm (n.s.) and increased laterally by 0.080+/-0.51mm (n.s.) during the time of observation. In knees with an MJS medially that was less or the same as compared with the lateral compartment, the MJS decreased by 0.14+/-0.38mm (p=0.038) and in a subgroup of these knees, without osteophytes, the MJS decreased by 0.14+/-0.27mm (p=0.018). The MJS of the PF joint decreased by 0.019mm (n.s.) during the time of observation. The coefficient of variation for intra- and interobserver MJS measurements of the TF joint was 1.0 and 1.1% medially and 2.3 and 2.7% laterally, and for measurement error 6.9% medially and 4.8% laterally, respectively. The coefficient of variation for intra- and interobserver MJS measurements of the PF joint was 8.1 and 5.8% medially and 7.5 and 10.1% laterally and for the measurement error it was 8.1% medially and 8.5% laterally, respectively. CONCLUSIONS: A statistically significant reduction of the MJS was only demonstrated in the medial compartment of the TF joint in those individuals who had an MJS in this compartment which was less or the same as compared with the lateral compartment as well as in a subgroup of these knees without osteophytes. The radiographic examinations and the MJS measurements were reproducible.