Fifty-seven consecutive patients received KJD. At baseline and at one year of follow-up, mean and minimum joint space width (JSW) of the most-affected compartment was determined on standardized radiographs. To evaluate the predictive ability of baseline characteristics for JSW at one year of follow-up, multivariable linear regression analysis was performed.
Mean JSW ± SD of the most affected compartment increased by 0.95 ± 1.23 mm to 3.08 ± 1.43 mm at one year (P < 0.001). The minimum JSW increased by 0.94 ± 1.03 mm to 1.63 ± 1.21 mm at one year of follow-up (P < 0.001). For a larger mean JSW one year after KJD, only Kellgren & Lawrence grade (KLG) at baseline was predictive (Regression coefficient (β) = 0.47, 95% CI = 0.18 to 0.77, P = 0.002). For a larger minimum JSW, KLG (β = 0.46, 95% CI = 0.19 to 0.73, P = 0.001) and male gender (β = 0.52, 95% CI = 0.06 to 0.99, P = 0.028) were statistically predictive. Eight weeks of distraction time neared significance (β = 0.44, 95% CI = − 0.05 to 0.93, P = 0.080).
In our cohort of patients treated with KJD, males with higher KLG had the best chance of cartilaginous tissue repair by distraction.