- This retrospective study included 234 patients who underwent revision total hip arthroplasty (THA) because of adverse local tissue reaction (ALTR) and were found to have grade 3 tissue necrosis and abductor muscle insufficiency
- Dislocation rates for the dual mobility (DM) implants (0%) and constrained liners (4%) were significantly lower than those for the conventional liners (16%; P<0.001) over an average follow-up period of four years (range, 2.8–8.6 years)
- Compared with conventional liners, the use of DM implants or constrained liners did not increase the risk of periprosthetic joint infection, fracture or recurrent ALTR
- Three patients who received DM implants (7%) developed iliopsoas tendonitis; all were treated with anti-inflammatory medications and physical therapy, and had not required surgical intervention at latest follow-up
- During revision total hip arthroplasty in the setting of significant abductor deficiency due to ALTR, dual mobility implants minimize dislocation and are viable surgical treatment alternatives to constrained liners
During revision total hip arthroplasty (THA) following adverse local tissue reaction (ALTR), necrotic abductor muscles that are critical for hip stability may need to be debrided. Dual mobility (DM) implant constructs have two articulations and are designed to improve range-of-motion before impingement when compared with conventional liners.
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For patients who have severe abductor muscle deficiency due to ALTR, a study at Massachusetts General Hospital suggests DM implants will provide greater postoperative hip joint stability compared with large-head conventional liners and similar stability compared with constrained liners. Christian Klemt, PhD, research fellow, Evan Smith, MD, arthroplasty fellow, Young-Min Kwon, MD, PhD, director of the Bioengineering Laboratory and the vice chair of clinical research in Mass General Department of Orthopaedic Surgery, and colleagues from the Lab detail their findings in The Journal of Arthroplasty.
The researchers retrospectively studied 234 patients who underwent revision THA and were noted to have grade 3 intraoperative tissue necrosis and abductor muscle deficiency. The average follow-up period was four years (range, 2.8–8.6 years).
At latest follow-up, the dislocation rates were:
- DM implants (n=42)—0%
- Constrained liners (n=24)—4%
- Conventional liners, non–large head diameter (≤32 mm) (n=64)—22%
- Conventional liners, large head diameter (>32 mm) (n=104)—11%
- All conventional liners (n=168)—16%
The dislocation rates for the DM implants and constrained liners were significantly lower than for conventional liners (P<0.001).
Other Postoperative Complications
There were no significant differences among the DM, constrained liner and conventional liner cohorts with respect to periprosthetic joint infection, fracture or recurrent ALTR.
At three-year follow-up, implant survival rates were:
- DM implants—87%
- Constrained liners—74%
- Conventional liners, non–large head diameter—59%
- Conventional liners, large head diameter—77%
Guidance for Surgeons
Several previous studies have identified concerns about aseptic loosening of constrained liner implants. Especially in light of that limitation, DM implants can be considered a viable alternative for patients with significant abductor deficiency.
Surgeons should be aware that although DM implants can be associated with iliopsoas tendonitis, dual mobility implants are viable surgical treatment alternatives to constrained liners for minimizing dislocation during revision THA in the setting of significant abductor deficiency due to ALTR.
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