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.

Knee laxity after complete anterior cruciate ligament tear: a prospective study over 15 years.

There is limited knowledge of knee laxity in the long term after a complete anterior cruciate ligament (ACL) tear treated without ACL reconstruction. The aim of this study was (1) to describe the clinical course of knee laxity after a complete ACL tear over 15 years, and (2) to study the association between knee laxity and meniscal injuries and the development of knee osteoarthritis (OA). We studied 100 consecutive subjects [mean (SD) age 26 (8) years] presenting with acute ACL injury prospectively. The initial treatment in all subjects was knee rehabilitation without reconstructive surgery. The subjects were examined with Lachman's and pivot-shift tests at baseline, 6 weeks, 3 months, 1 year, 3 years and 15 years after the injury. Sagittal knee laxity was also evaluated with the KT-1000 arthrometer at the 15-year follow-up. During follow-up, 22 subjects were ACL reconstructed due to unacceptable knee instability. There was only a mild remaining knee laxity [median Lachman grade and pivot-shift test value of 1 on a 4-grade scale (0-3)] after 15 years in subjects treated without primary ACL reconstruction. Knees with higher anterior sagittal knee laxity 3 months after the injury had a worse long-term outcome with respect to meniscal injuries and knee OA development.

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.

Patellofemoral osteoarthritis 15 years after anterior cruciate ligament injury--a prospective cohort study.

OBJECTIVE: Prevalence and clinical relevance of patellofemoral (PF) osteoarthritis (OA) after anterior cruciate ligament (ACL) injury. METHOD: Prospectively we studied 94 out of 100 consecutive patients 15 years after acute ACL injury. ACL reconstructions were only performed late if recurrent "give way" persisted or a secondary meniscal injury suitable for repair occurred. The subjects, mean age 42 years, had knee radiographs including skyline PF view taken, which were graded according to the atlas of the Osteoarthritis Research Society International. Knee-related symptoms and function were assessed by questionnaires. RESULTS: PF OA was present in 12/75 knees (16%). Of 94 patients 22 (23%) have had their ACL reconstructed during follow-up. Meniscal injury and ACL reconstruction had occurred more often in knees with PF OA than in knees without PF OA (P=0.004 and P=0.002, respectively). Seven of 15 ACL reconstructed knees showed radiographic PF OA at follow-up. Knees with PF OA had more extension and flexion deficit than knees without PF OA. Subjects with PF OA maintained a higher activity level from injury to follow-up, but did not differ significantly from those without PF OA regarding patient-relevant symptoms and knee function. However, there was a trend for worse outcome in subjects with PF OA. CONCLUSION: We found a relatively low prevalence of mild PF OA after ACL injury treated non-operatively, and it had limited impact on knee symptoms and patient-relevant knee function. At follow-up PF OA was associated with higher activity level, meniscal injury, extension and flexion deficit, and ACL reconstruction.