Abstract
Complete or nearly complete disruption of the attachment of the gluteus is seen in 10–20% of cases at the time of THA. Special attention is needed to identify the lesion at the time of surgery because the avulsion often is visible only after a thickened hypertrophic trochanteric bursa is removed. From 1/1/09 to 12/31/13, 525 primary hip replacements were performed by a single surgeon. After all total hip components were implanted, the greater trochanteric bursa was removed, and the gluteus medius and minimus attachments to the greater trochanter were visualised and palpated. Ninety-five hips (95 patients) were found to have damage to the muscle attachments to bone. Fifty-four hips had mild damage consisting of splits in the tendon, but no frank avulsion of abductor tendon from their bone attachments. None of these cases had severe atrophy of the abductor muscles, but all had partial fatty infiltration. All hips with this mild lesion had repair of the tendons with #5 Ticron sutures to repair the tendon bundles together, and drill holes through bone to anchor the repair to the greater trochanter. Forty-one hips had severe damage with complete or nearly complete avulsion of the gluteus medius and minimus muscles from their attachments to the greater trochanter. Thirty-five of these hips had partial fatty infiltration of the abductor muscles, but all responded to electrical stimulation. The surface of the greater trochanter was denuded of soft tissue with a rongeur, the muscles were repaired with five-seven #5 Ticron mattress sutures passed through drill holes in the greater trochanter, and a gluteus maximus flap was transferred to the posterior third of the greater trochanter and sutured under the vastus lateralis. Six hips had complete detachment of the gluteus medius and minimus muscles, severe atrophy of the muscles, and poor response of the muscles to electrical stimulation. The gluteus medius and minimus muscles were sutured to the greater trochanter, and gluteus maximus flap was transferred as in the group with functioning gluteus medius and minimus muscles. Postoperatively, patients were instructed to protect the hip for 8 weeks, then abductor exercises were started.
The normal hips all had negative Trendelenburg tests at 2 and 5 years postoperative with mild lateral hip pain reported by 11 patients at 2 years, and 12 patients at 5 years. In the group of 54 with mild abductor tendon damage that were treated with simple repair, positive Trendelenburg test was found in 5 hips at 2 years and in 8 hips at 5 years. Lateral hip pain was reported in 7 hips at 2 years, and in 22 at 5 years. In the group of 35 hips with severe avulsion but good muscle tissue, who underwent repair with gluteus maximus flap transfer, all had good abduction against gravity and negative Trendelenburg tests at 2 and 5 years postoperative, and none had lateral hip pain. Of the 6 hips with complete avulsion and poor muscle who underwent abductor muscle repair and gluteus maximus flap transfer, all had weak abduction against gravity, mildly positive Trendelenburg sign, and mild lateral hip pain at 2 and 5 years postoperative. Abductor avulsion is uncommon but not rare, and is detected during THA only by direct examination of the tendon and removal of the trochanteric bursa. Simple repair of mild abductor tendon damage did not prevent progressive abductor weakness in some hips; and the increase in number of patients with lateral hip pain from 2 to 5 years suggests progressive deterioration. Augmentation of the repair with a gluteus maximus flap appears to provide a stable reconstruction of the abductor muscles, and seemed to restore abductor function in the hips with functioning muscles.
