The effect of gluteus maximus tenotomy in primary total hip arthroplasty with posterior approach: Kinematic analysis of hip extensor strength

Abstract

Background: The posterior approach (PA) is the most commonly used surgical approach for total hip arthroplasty (THA), but the proximity of the sciatic nerve may increase the likelihood of sciatic nerve injury (SNI). Gluteus maximus tenotomy can be performed to prevent SNI because tenotomy increases the distance between the femoral neck and sciatic nerve and prevents compression of the sciatic nerve by the gluteus maximus tendon (GMT) during hip movements. We aimed to kinematically compare the postoperative hip extensor forces of patients who have and have not undergone gluteus maximus tenotomy to determine whether there is a difference in hip extensor strength. Methods: Seventy-two patients who underwent gluteus maximus tenotomy during THA were included in the group 1, and 86 patients who did not undergo tenotomy were included in group 2. The Harris hip score, body mass index and hip extensor forces were measured both preoperatively, and 6 months after surgery with an isokinetic dynamometer and compared. Results: The mean age was 64.6 ± 2.3 years in group 1 and 63.8 ± 2.1 in group 2. Mean body mass index was 25.7 ± 1.1 in group 1, and 25.5 ± 1.3 in group 2. Baseline Harris hip score (HHS) was 42.36 ± 12 in group 1 and 44.07 ± 9.4 in group 2 (p = 0.31), whereas it was 89.1 ± 7.8 and 88.4 ± 8.1 at 6 months after surgery, respectively. Baseline hip extensor force (HEF) was 2 ± 0.4 Nm/kg in group 1, and 2.1 ± 0.7 Nm/kg in group 2 (p = 0.28), while it was 2.4 ± 0.6 Nm/kg, and 2.5 ± 0.5 Nm/kg, respectively at 6 month follow-up (p = 0.87). Both groups had significantly improved HHS and HEF when comparing baseline and postoperative measurements (p < 0.0001). No cases of sciatic nerve palsy were noted in group 1, whereas there were two (2.32%) cases in group 2, postoperatively. Conclusion: The release of the GMT during primary hip arthroplasty performed with the PA did not lead to significant decrease in hip extension forces. Hip extensor strength improves after THA regardless of tenotomy. Gluteus maximus tenotomy with repair does not reduce muscle strength and may offer better visualization.

Do Different Approaches Make a Difference in Isokinetic Performance in Elderly Patients With Femoral Neck Fracture Who Underwent Bipolar Endoprosthesis?

“…It has also been suggested that damage to the hip extensor muscle group may occur with the PLA approach [ 11 , 12 ]. However, Imren et al found that there was no significant decrease in hip extension strength in patients who underwent total hip arthroplasty with PLA [ 22 ]. In this study, the isokinetic values ​​of both the operated and non-operated hips did not show a statistically significant difference between the PLA and ALA groups.…”

Sciatic Nerve Palsy After Total Hip Arthroplasty

“…GMT releases with subsequent repair can be safely performed in primary total hip arthroplasty through the posterolateral approach, without any residual weakness to the hip extensors, to aid the surgeon in visualization and decrease the risk of SN injury 5,21 . Initially, patients may have difficulty climbing stairs or walking up an incline but that will resolve in almost all cases 21 .…”

“…The deep gluteal space is bordered by the gluteus maximus posteriorly, the posterior acetabular column anteriorly, the gluteal tuberosity laterally, the sacrotuberous ligament medially, the inferior margin of the sciatic notch superiorly, and the ischial tuberosity inferiorly 5 . Because the SN lies medial and deep to the deep fibers of the gluteus maximus tendon (GMT) insertion on the gluteal tuberosity, the nerve can get compressed with hip flexion and internal rotation, between the ischial tuberosity and the GMT 5,21 . Furthermore, it resumes to travel through the posterior compartment of the thigh and innervates the muscles of the posterior thigh.…”

“…This number can be even higher because electromyographic (EMG) studies performed after a routine total hip replacement have demonstrated that a subclinical injury could occur in up to 70% of the cases 11 . Although there are multiple causes described in the literature that can cause a SN palsy, in 50% of cases the reason remains unknown 5,13,21 . Studies have shown revision surgery, surgeon inexperience, female gender, underlying spinal stenosis, and hip dysplasia as some risk factors for SN palsies.…”