Long-term followup of surgically treated knee dislocations: stability restored, but arthritis is common.

BACKGROUND

Surgical treatment of knee dislocations is intended to correct the anatomic injury and restore knee stability and patient function. Several studies have shown successful results with surgical treatment of knee dislocations with up to 10 years of followup, but longer-term studies are uncommon.

QUESTIONS/PURPOSES: We evaluated patients treated surgically for knee dislocations at 10-year followup to assess (1) knee stability; (2) return to preinjury level of function; (3) development of arthrosis; and (4) range of motion (ROM) loss.

METHODS

This study was a retrospective review of 127 combined PCL, ACL, and medial and/or lateral side reconstructions performed by a single surgeon (GCF) between 1990 and 2008. Of these, 44 were available for clinical and functional evaluation (35%) at a minimum 5-year followup. Inclusion criteria were combined PCL/ACL plus medial and/or lateral side reconstruction. Evaluation methods included arthrometer measurements, stress radiography, knee ligament rating and activity scales (Lysholm and Tegner), plain radiographs with osteoarthritic assessment, and physical examination.

RESULTS

Of the 44 patients, there were nine ACL/PCL medial, 22 ACL/PCL lateral, and 13 ACL/PCL mediolateral reconstructions. Followup was at a minimum of 5 years (mean, 10 years; range, 5-22 years). The mean age at the time of injury was 31 years with a range of 13 to 65 years. The mean arthrometer-measured side-to-side differences were as follows: PCL screen, 1.9 mm; corrected posterior, 2.4 mm; corrected anterior, 0.8 mm; and anterior displacement at 30° of knee flexion, 1.7 mm. Stress radiographic measurements at 90° of knee flexion revealed a mean side-to-side difference of 1.9 mm. Mean Lysholm, and Tegner scores were 84 of 100 and 4.1 of 9, respectively. Ninety-three percent (41 of 44) of patients returned to their preinjury level of activity or one Tegner grade lower. Ten of the 44 knees (23%) developed degenerative joint disease. The mean flexion loss was 12.5°, and flexion contractures were not seen in any of the patients.

CONCLUSIONS

We found that a high proportion of patients treated for these severe injuries achieved static and functional stability, allowing the return to physically demanding work and recreational activities, but that nearly one-fourth of them will develop arthritis at a mean of 10 years. We cannot extrapolate our results to an elite athlete population, but our results probably apply well to working class populations.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.