Anterior knee pain after intramedullary nailing of fractures of the tibial shaft. A prospective, randomized study comparing two different nail-insertion techniques.

BACKGROUND:
Anterior knee pain is the most common complication after intramedullary nailing of the tibia. Dissection of the patellar tendon and its sheath during nailing is thought to be a contributing cause of chronic anterior knee pain. The purpose of this prospective, randomized study was to assess whether the prevalence or the intensity of anterior knee pain following intramedullary nailing of a tibial shaft fracture is reduced by the use of a paratendinous incision for the nail entry portal.

METHODS:
Fifty patients with a tibial shaft fracture requiring intramedullary nailing were randomized equally to treatment with paratendinous or transtendinous nailing. Twenty-one patients from both study groups were followed for an average of three years after nailing. After fracture union, all but two patients had elective nail removal through the same surgical approach as was used for the nailing. At the follow-up evaluation, the patients used visual analog scales to report their level of anterior knee pain and the impairment caused by that pain. The scales described by Lysholm and Gillquist and by Tegner et al., the Iowa knee scoring system, and simple functional tests were used to quantitate the functional results. Isokinetic thigh-muscle strength was also measured.

RESULTS:
Fourteen (67%) of the twenty-one patients treated with transtendinous nailing reported anterior knee pain at the final evaluation. Of these fourteen patients, thirteen were mildly to severely impaired by the pain. Fifteen (71%) of the twenty-one patients treated with paratendinous nailing reported anterior knee pain, and ten of the fifteen were impaired by the pain. The Lysholm, Tegner, and Iowa knee scoring systems; muscle-strength measurements; and functional tests showed no significant differences between the two groups.

CONCLUSION:
Compared with a transpatellar tendon approach, a paratendinous approach for nail insertion does not reduce the prevalence of chronic anterior knee pain or functional impairment by a clinically relevant amount after intramedullary nailing of a tibial shaft fracture.