Abductor Mechanism Deficiency after Total Hip Arthroplasty
The authors review the clinical scenarios in which abductor deficiency generally presents, as well as the options for managing this challenging complication of THA.
Nicholas J. Clark, MD, and Rafael J. Sierra, MD
The authors have no disclosures relevant to this article.
Abductor mechanism deficiency after total hip arthroplasty (THA) is a challenging problem. It is most commonly observed after anterolateral approach THA, direct lateral approach THA, and revision THA. The frequency of abductor deficiency varies in different patient populations, ranging from 1% after primary THA done through an anterolateral approach to as high as 21% in patients undergoing revision THA for instability. [1,2]
Abductor deficiency generally presents as 3 distinct clinical scenarios:
- The patient presents with moderate abductor deficiency and limp, often with some lateral hip pain, but without THA instability. This most commonly is seen after THA performed through an anterolateral approach, with a failed abductor tendon and/or muscle repair.
- The patient presents with severe abductor-related Trendelenburg limp with varying degrees of pain. This may occur in patients with either trochanteric avulsion fracture or complete avulsion of the abductor mechanism from the bone. A common scenario is the patient with severe adverse local soft-tissue reaction due to metal ions with muscle necrosis.
- The patient presents with recurrent dislocations of the hip in association with abductor deficiency. In cases in which there is no apparent etiology for the dislocation, abductor muscle necrosis often seen in cases with severe taper corrosion should be investigated.
Appropriate testing is essential for any patient presenting with suspected abductor insufficiency:
- Radiographs. Anteroposterior and lateral radiograph of the hip help the surgeon evaluate implants and rule out trochanteric fractures.
- Magnetic resonance imaging (MRI). The tendinous attachment on the trochanter can be evaluated with MRI, with the T1 weighted axial view used to determine atrophy of the gluteus medius and minimus muscle (Figure 1). Although fatty atrophy of the anterior two thirds of the gluteus minimus is common in symptomatic and asymptomatic patients after THA, fatty atrophy of gluteus medius and posterior portion of the gluteus minimus is considered pathologic. 
Figure 1. Left hip magnetic resonance axial T1 imaging demonstrating fatty infiltration of the gluteus medius and minimus in the setting of previous bipolar hemiarthroplasty.
Cobalt and chromium serum levels should be measured to rule out taper corrosion if the MRI demonstrates fluid collection that may indicate an adverse local tissue reaction.  In addition, patients may undergo an electromyogram if compromise of the superior gluteal nerve is suspected. If a patient presents with recurrent dislocation, the aim of treatment is to first provide a stable joint, taking into account that treating the abductor deficiency has the potential to decrease the risk of subsequent dislocations or failure of implants used to stabilize the hip.
Options for Treating Abductor Damage
Two important factors will influence the choice of abductor reconstruction:
- The status of the abductor muscles as evidenced by axial T1 MRI imaging and their innervation as evidenced by the electromyogram.
- The presence and quality of the greater trochanter or proximal bone.
The abductor musculature should be reattached to bone if no fatty atrophy is noted on the axial T1 MRI and the muscles contract at the time of surgery. Alternative treatment options should be sought if these circumstances are not present, however.
There are 3 options for treating abductor damage after THA:
- Direct repair of the abductors plus or minus an augmentation of the repair [1,5-7]
- Local muscle transfer [8,9]
- Abductor reconstruction with a structure that bridges a gap or provides a tendodesis effect to the detached abductors (Achilles tendon or extensor mechanism allograft) [10,11]
Direct Repair with Augmentation
Direct repair should be considered if abductor damage is noted after a direct lateral or anterolateral approach and the axial T1 MRI shows no evidence of fatty atrophy. Weber and Berry  reported on 9 patients 2 to 13.5 years after abductor mechanism repair. Six of the 9 patients were satisfied after treatment. Limp and the use of ambulatory aids had decreased in 5 of the 9 patients. Less preoperative pain and the use of a postoperative spica cast seemed to be associated with better results.
Lubbeke et al  reported on 19 patients with an average follow-up of 38 months, with limp and pain improving in 50% of patients. A successful repair was achieved when performed within 15 months of the index THA. Predictors of failure included increased body mass index and not using an orthosis postoperatively.
In another article, Miozzari et al  reported on 12 patients undergoing repair of the abductors. Seventy-five percent were satisfied, and 7 of the 12 with postoperative MRIs showed evidence of healing of the repair. Interestingly, postoperative MRIs did not show improvement in fatty degeneration, even for those who had a successful repair.
Finally, Rao et al  reported on direct repair of the abductors with augmentation using an allograft acellular dermal matrix (GRAFTJACKET Regenerative Tissue Matrix; Wright Medical Technology, Memphis, Tennessee). This on-lay augmentation was used to cover the bare area that remained present after repairing the gluteus medius and minimus to the greater trochanter. The authors noted significant improvement in visual analog pain scales and an improvement in Trendelenburg gait; at a mean follow-up of 22 months, Harris hip scores had improved from 34 to 81 points. It should be noted that these latter results are better than direct repair without augmentation.
In summary, a direct repair is best if done within 15 months of the index THA and may be more successful if the repair is augmented with an allograft matrix or some other tissue (Achilles tendon allograft is the authors’ choice; Figure 2). In addition, the results may be more successful if the repair is protected in a brace or cast (authors’ choice). Fatty degeneration of the muscle will not improve after the direct repair, and the more muscle atrophy present, the less chance of a full functional recovery.
Figure 2. (A) Intraoperative image revealing bald trochanter. Note the split of the gluteus medius which is held by the Kocher anteriorly. (B) The gluteus medius has been repaired primarily using non-absorbable suture. The Achilles allograft has been fixed distally and prepared for augmentation proximally. (C) The Achilles allograft has been secured to augment the gluteus medius repair using non-absorbable suture in a Krakow fashion.
Local Muscle Transfers
Local muscle transfer may be indicated in patients with severe abductor muscle fatty atrophy, local destruction of the abductors, or notably compromised greater trochanteric bed for abductor reattachment (trochanteric fractures, proximal femoral arthroplasties). Two types of procedures – vastus lateralis  and gluteus maximus and fascia lata transfer  – have been reported in these cases, with varying degree of success. In general, the results are better when the trochanter is present and the muscles can be transferred and attached to a live trochanter.
The vastus lateralis advancement was initially described by Beck et al in 2004.  A subsequent article demonstrated that the vastus lateralis advancement improved pain and gait in most patients; however, a maximal abductor strength of 4 of 5 was obtained.  This is an important finding and a limitation of the technique. Patients with no proximal bone have undergone vastus lateralis advancement, but the procedure is technically demanding, requires allograft bone, and the results are not as predictable as attaching the proximal vastus lateralis to the gluteus medius directly.
A gluteus maximus transfer, as described by Whiteside, [9,13] transfers the anterior aspect of the gluteus maximus to the trochanter followed by a transfer of the fascia lata distally (Figure 3). Whiteside reported on 11 patients, all of whom had marked improvement in their limp and weakness despite no gluteus medius contraction being palpable on preoperative examination. Of the 11 patients, 10 patients had significant improvement, and 9 patients no longer had a Trendelenburg sign or limp.
Figure 3. (A) Intraoperative photo through split in atrophic gluteus medius. The Kocher is placed on the anterior portion of the gluteus medius which is in continuity with the vastus lateralis distally. (B) The Kocher is attached the gluteus maximus. The line denotes the anterior limb of the gluteus maximus that will serve as the transferred muscle. (C) The anterior limb of the gluteus maximus has been transferred and attached to the trochanter using multiple transosseous, non-absorbable sutures. (D) The gluteus medius which was split in figure A is attached over the transferred gluteus maximus using non-absorbable sutures in a Krakow fashion.
Muscle transfers are complex techniques that require extensive exposure and require sacrifice of other muscles to improve function. Although transfer of the gluteus maximus has been reported to provide near normal function in some patients, the vastus lateralis transfer may only improve strength by 1 or 2 grades. These transfers are best suited for patients with severe abductor insufficiency, in which the gluteus medius and minimus cannot be repaired and/or have undergone significant fatty infiltration.
Allograft and Prosthetic Reconstruction
Allograft reconstruction of the abductor mechanism may be useful in cases in which a transfer is not possible or a short gap remains after a primary repair. The allograft tissue is used to augment or bridge a gap, aid direct soft-tissue healing, or create a tenodesis effect of the torn abductors to the bone.
The 2 reported allograft abductor reconstruction mechanism techniques are use of Achilles tendon  and use of the extensor mechanism allograft. 
Repair of the deficient abductor mechanism with Achilles tendon allograft after THA was reported by Fehm et al.  The authors reported on 7 patients, of whom 5 had an abductor avulsion and 2 had a trochanteric fracture. The Achilles tendon allograft was inserted into a recess in the trochanteric bone and woven through the gluteus medius and then fixed back onto itself in an effort to reinforce the abductors to the trochanter. Patients were then placed in an abductor brace after fixation. All but 1 patient (6 of 7) had improvements in pain and limp. It is important to note that this technique requires a viable trochanter.
Drexler et al  reported on the use of a knee extensor mechanism allograft. The allograft patella is fashioned and fixed to the trochanter, while the quadriceps tendon is sutured to the gluteus medius and the patellar tendon to the vastus lateralis. This technique was used in 11 patients with a severe limp and pain. The outcome was good in 5 patients, fair in 2, and poor in 4. The patients with poor function had detachment of the proximal limb of the reconstruction. The authors noted the limitations of their technique, especially when no trochanteric bone was present.
Caviglia et al  presented a technique using mesh to span the gap between the gluteus medius and vastus lateralis in 46 patients with trochanteric bone loss. The mesh is sutured to the proximal, anterior, and posterior portions of the gluteus medius. The vastus lateralis and gluteus medius are then mobilized to minimize the gap between them, and the mesh is used to span the gap. The mesh is sutured 15 to 20 cm distally along the vastus lateralis for fixation. All 46 patients initially presented with a Trendelenburg sign and positive stair climbing test. After reconstruction, 75% of the patients had a negative Trendelenburg sign and 60% had a negative stair climbing sign.
The techniques can be summarized as follows: Both the Achilles tendon and the extensor mechanism reconstructions need trochanteric attachment for best results. When trochanteric attachment is not an option, mesh reconstruction can be considered. The techniques are best suited to patients with small gaps after primary abductor repair, and the native muscle must not be atrophied; otherwise, they will simply serve as a checkrein and may not improve function dramatically.
All these techniques function worse than the reported muscle transfers; however, they have the advantage of not sacrificing other muscles. They have drawbacks associated with the costs of allograft tissue or mesh material and the potential risk of infection with allograft material.
Abductor insufficiency is a catastrophic problem for patients with THA. There are 3 main treatment options available, with variable success rates. The degree of disability and the status of the gluteus medius muscle and trochanteric bone will dictate which option is best in the selected case. In general, earlier repair is advantageous to try to avoid muscle fatty infiltration. Postoperatively restricting hip range of motion with spica casts or braces may be critical to success of these procedures.
Key Studies on Abductor Deficiency after THA
Weber M, Berry DJ. Abductor avulsion after primary total hip arthroplasty. Results of repair. J Arthroplasty. 1997;12(2):202-206.
Why it’s important: This report describes the outcomes of 9 patients after undergoing direct repair of abductor avulsions. Follow-up ranged from 2 to 13.5 years. Two thirds of the patients were satisfied after repair, with use of ambulatory aids decreasing in 5 of the 9 patients. Indicators of successful repair included less preoperative pain and the use of spica cast postoperatively.
Pfirrmann CW, Notzli HP, Dora C, Hodler J, Zanetti M. Abductor tendons and muscles assessed at MR imaging after total hip arthroplasty in asymptomatic and symptomatic patients. Radiology. 2005;235(3):969-976.
Why it’s important: MRI of 25 asymptomatic and 39 patients with trochanteric pain after THA were analyzed by 2 senior musculoskeletal radiologists. Tendon defects were present in a significantly higher proportion of symptomatic patients. MRI changes were common in both groups. Fatty atrophy of the anterior two thirds of the gluteus minimus was common in both symptomatic and asymptomatic patients after THA. However, fatty atrophy of gluteus medius and posterior portion of the gluteus minimus was only present in symptomatic patients, and should be considered pathologic.
Lübbeke A, Kampfen S, Stern R, Hoffmeyer P. Results of surgical repair of abductor avulsion after primary total hip arthroplasty. J Arthroplasty. 2008;23(5):694-698.
Why it’s important: Outcomes of 19 patients treated with repair of avulsed abductor mechanism. The authors noted an improvedment in patient symptoms in 50% of the patients. Patients undergoing repair within 15 months of THA and those who used a brace postoperatively were more likely to have improvement after the procedure.
Miozzari HH, Dora C, Clark JM, Nötzli HP. Late repair of abductor avulsion after the transgluteal approach for hip arthroplasty. J Arthroplasty. 2010;25(3):450-457.e451.
Why it’s important: Outcomes of 12 patients who underwent repair of abductor mechanism. Seven of the patients showed healing of the repair, and 75% of the patients were satisfied. However, postoperative MRI did not show any change from preoperative fatty degeneration, even in those patietns with successful healing of the repair.
Rao BM, Kamal TT, Vafaye J, Taylor L. Surgical repair of hip abductors. A new technique using Graft Jacket allograft acellular human dermal matrix. Int Orthop. 2012;36(10):2049-2053.
Why it’s important: The authors describe the outcomes of 12 patients treated with repair of abductors augmented with GRAFTJACKET material. Significant improvements were noted in the Visual Analog Scoring, Trendelenburg gait, and Harris hip scores from 34 to 81 points at an average 22 month follow up. These results are better than repair is performed without augmentation.
Kohl S, Evangelopoulos DS, Siebenrock KA, Beck M. Hip abductor defect repair by means of a vastus lateralis muscle shift. J Arthroplasty. 2012;27(4):625-629.
Why it’s important: Describes the vastus lateralis muscle transfer for hip abductor deficiency. This technique demonstrated significant improvements in pain and gait in 10 of 11 patients. However, abductor strength was noted to be 4/5 in all successful cases.
Whiteside LA. Surgical technique: Transfer of the anterior portion of the gluteus maximus muscle for abductor deficiency of the hip. Clin Orthop Relat Res. 2012;470(2):503-510.
Why it’s important: The authors describe the technique of transferring the anterior portion of the glutues maximus and fascia lata in 11 patients. All of the patients had significant improvements in strength and decrease in their limp. After the transfer, 9 of the 11 patients no longer demonstarted a Trendelenburg gait.
Drexler M, Abolghasemian M, Kuzyk PR, et al. Reconstruction of chronic abductor deficiency after revision hip arthroplasty using an extensor mechanism allograft. Bone Joint J. 2015;97-B(8):1050-1055.
Why it’s important: This report describes the use a knee extensor mechanism allograft to reconstruct the abductor mechanism in 11 patients. Five patients achieved a good outcome, 2 patients had a fair outcome, and 4 patients had a poor outcome. All patients with a poor outcome had detachement of the proximal limb of the reconstruction from the gluteus medius.
Fehm MN, Huddleston JI, Burke DW, Geller JA, Malchau H. Repair of a deficient abductor mechanism with Achilles tendon allograft after total hip replacement. J Bone Joint Surg Am. 2010;92(13):2305-2311.
Why it’s important: The authors report on 7 patients who underwent reconstruction of abductor deficiency using an Achilles allograft. Six of the 7 patients had improvements in pain and limp after reconstruction.
Nicholas J. Clark, MD, and Rafael J. Sierra, MD, are from the Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota.
- Weber M, Berry DJ. Abductor avulsion after primary total hip arthroplasty. Results of repair. J Arthroplasty. 1997;12(2):202-206.
- Jo S, Jimenez Almonte JH, Sierra RJ. The Cumulative Risk of Re-dislocation After Revision THA Performed for Instability Increases Close to 35% at 15years. J Arthroplasty. 2015;30(7):1177-1182.
- Pfirrmann CW, Notzli HP, Dora C, Hodler J, Zanetti M. Abductor tendons and muscles assessed at MR imaging after total hip arthroplasty in asymptomatic and symptomatic patients. 2005;235(3):969-976.
- Cooper HJ, Della Valle CJ, Berger RA, et al. Corrosion at the head-neck taper as a cause for adverse local tissue reactions after total hip arthroplasty. J Bone Joint Surg Am. 2012;94(18):1655-1661.
- Lübbeke A, Kampfen S, Stern R, Hoffmeyer P. Results of surgical repair of abductor avulsion after primary total hip arthroplasty. J Arthroplasty. 2008;23(5):694-698.
- Miozzari HH, Dora C, Clark JM, Nötzli HP. Late repair of abductor avulsion after the transgluteal approach for hip arthroplasty. J Arthroplasty. 2010;25(3):450-457.e451.
- Rao BM, Kamal TT, Vafaye J, Taylor L. Surgical repair of hip abductors. A new technique using Graft Jacket allograft acellular human dermal matrix. Int Orthop. 2012;36(10):2049-2053.
- Kohl S, Evangelopoulos DS, Siebenrock KA, Beck M. Hip abductor defect repair by means of a vastus lateralis muscle shift. J Arthroplasty. 2012;27(4):625-629.
- Whiteside LA. Surgical technique: Transfer of the anterior portion of the gluteus maximus muscle for abductor deficiency of the hip. Clin Orthop Relat Res. 2012;470(2):503-510.
- Drexler M, Abolghasemian M, Kuzyk PR, et al. Reconstruction of chronic abductor deficiency after revision hip arthroplasty using an extensor mechanism allograft. Bone Joint J. 2015;97-B(8):1050-1055.
- Fehm MN, Huddleston JI, Burke DW, Geller JA, Malchau H. Repair of a deficient abductor mechanism with Achilles tendon allograft after total hip replacement. J Bone Joint Surg Am. 2010;92(13):2305-2311.
- Beck M, Leunig M, Ellis T, Ganz R. Advancement of the vastus lateralis muscle for the treatment of hip abductor discontinuity. J Arthroplasty. 2004;19(4):476-480.
- Whiteside LA. Surgical technique: Gluteus maximus and tensor fascia lata transfer for primary deficiency of the abductors of the hip. Clin Orthop Relat Res. 2014;472(2):645-653.
- Caviglia H, Cambiaggi G, Vattani N, Landro ME, Galatro G. Lesion of the hip abductor mechanism. SICOT J. 2016;2:29.