Damage of the superior gluteal nerve after the lateral transgluteal approach of the hip. anatomical, clinical and electrophysiological study

Twenty-two patients who had undergone unilateral hip athroplasty using the transgluteal approach of Hardinge were studied. The abductor muscles of the hip joint were assessed electrophysiologically and clinically by Trendelenberg test six months after the operation. Electrophysiological evidence of damage of the superior gluteal nerve was found in two patients, while positive Trendelenberg was present in seven cases. In an effort to understand the mechanism of injury of the nerve, ten Egyptian cadavers were bilaterally dissected to expose the superior gluteal nerve. The course, pattern of branching and distribution of the nerve were evaluated. Two patterns of nerve distribution were recorded. The spray pattern in 90% of cadavers and the transverse neural trunk pattern in the remaining 10%. In both patterns all branches lied deep to the middle third of the undersurface of the gluteus medius muscle. A safe area devoid of any neural branches was detected in all cadavers. It is safe to extend the incision up to 4.8cm in a cephalic direction from the tip of the greater trochanter, before reaching the lower most branch of the superior gluteal nerve

Evaluation of the donor site after harvesting the central third of the patellar tendon

The purpose of this study was to evaluate the donor site after use of the central third of the patellar tendon, as a free autograft for anterior cruciate ligament [ACL] reconstruction. Twelve consecutive patients were evaluated clinically and serially imaged with magnetic resonance image [MRI], two years after operation. The tendon defect was not closed primarily, but the paratenon [peritendon] was approximated. Examination of knee walking ability and assessment of the anterior knee sensitivity were made in order to evaluate donor site discomfort and the function of the infrapatellar nerves. 75% of the patients had disturbed anterior knee sensitivty with a median value of 16 cm2. Knee walking ability was unpleasant or difficult in 67% of cases. In the MRI evaluation the following measurements were performed: tendon width, defct width, tendon thickness and tendon length. All measurements were compared to the contralateral unoperated patellar tendon. Complete closure of the tendon defect was detected in four cases, while the mean tendon defect was 2mm [range 0-5mm]. Tendon width was increased [p=0.022]. Tendon thickness was also increased [p=0.035], but tendon length was noted to be decreased [p= 0.017]. Degenerative changes of the lateral third of the patellar tendon were detected in one case. The bony defect in the anterior surface of the patella and tibial tuberosity was present in all cares. The retropateller fat pad was found to be hypertrophied in six cases. Presence of a gap in the middle of the fat pad was detected in four cases. Presence of changes in the donor site after harvesting the patellar tendon autograft may explain the increased incidence of anterior knee pain after ACL reconstruction