Do the Loss of Thigh Muscle Strength and Tibial Malrotation Cause Anterior Knee Pain after Tibia Intramedullary Nailing?

PURPOSE

Anterior knee pain (AKP) is a common complication after tibia intramedullary nailing surgery, but yet the etiology is not fully revealed. Our study had two hypotheses. The first one is "after tibia intramedullary nailing with transtendinous approach, thigh muscles strength decreases and this loss of muscle strength causes AKP." Secondly, "lower extremity rotational profile is affected after tibia intramedullary nailing." . Our study was planned retrospectively and included 40 patients, who underwent tibia intramedullary nailing surgery. Mean follow-up time was 22.5 months. Tegner Lysholm knee scoring scale was applied to evaluate postoperative functional outcomes of all patients. Isometric muscle strengths of bilateral knee extensor and flexor muscle groups were compared with hand-held dynamometer. In addition, bilateral lower extremity Staheli rotational profile angles (foot progression angle (FPA), thigh-foot angle (TFA), and transmalleolar angle (TMA)) were compared.

RESULTS

Lysholm knee score was evaluated as excellent in 28 patients. AKP were detected in 15 patients and there was no significant difference between the injured limb with contralateral quadriceps mean muscle strength (injured limb mean (ILM) = 201.97 Newton (N) - contralateral mean (CM) = 205.4 N). However, there was a significant difference (p<0,05) between injured limb with contralateral extremity hamstring mean muscle strength (ILM = 153.2 N- CM=158.95 N). Although there was a significant difference between the two extremities' rotational profile angles, there was no significant correlation between the rotational profile angles and knee pain.

CONCLUSION

As a result of our study, AKP appears to be significantly related to the loss of hamstring muscle strength. We suppose that hamstring exercises will gain importance in rehabilitation programs of tibia intramedullary nailing surgery in future.