Dislocation After Total Hip Arthroplasty Using the Anterolateral Abductor Split Approach

487

406

Background Few studies have examined factors that affect acetabular cup positioning. Since cup positioning has been linked to dislocation and increased bearing surface wear, these factors affecting cup position are important considerations. Question/purposes We determined the percent of optimally positioned acetabular cups and whether patient and surgical factors affected acetabular component position. Methods We obtained postoperative AP pelvis and crosstable lateral radiographs on 2061 consecutive patients who received a THA or hip resurfacing from 2004 to 2008. One thousand nine hundred and fifty-two hips had AP pelvic radiographs with correct position of the hip center, and 1823 had both version and abduction angles measured. The AP radiograph was measured using Hip Analysis Suite TM to calculate the cup inclination and version angles, using the lateral film to determine version direction. Acceptable ranges were defined for abduction (30°-45°) and version (5°-25°).Results From the 1823 hips, 1144 (63%) acetabular cups were within the abduction range, 1441 (79%) were within the version range, and 917 (50%) were within the range for both. Surgical approach, surgeon volume, and obesity (body mass index [ 30) independently predicted malpositioned cups.

Section: Introductionmentioning

confidence: 99%

The John Charnley Award: Risk Factors for Cup Malpositioning: Quality Improvement Through a Joint Registry at a Tertiary Hospital

Callanan

Jarrett

Bragdon

et al. 2011

487

406

“…Reported incidence ranges from less than 1% to 5% with a recent Medicare claims data analysis of 58,521 patients reporting 3.9% dislocation in the first 26 weeks postoperative [31]. Numerous patient factors may contribute to increased dislocation risk: aging, female gender, lower muscular disorders, cognitive dysfunction, dysplasia, previous femoral neck fracture, and rheumatoid arthritis [9,18,21,24,26,29,41]. The correlation between higher surgeon and hospital volume and lower dislocation rates has also been established [20].…”

Section: Introductionmentioning

confidence: 99%

Do Large Heads Enhance Stability and Restore Native Anatomy in Primary Total Hip Arthroplasty?

Lombardi¹,

Skeels

Berend

et al. 2011

104

Background Dislocation remains a serious complication in hip arthroplasty. Resurfacing proponents tout anatomic femoral head restoration as an advantage over total hip arthroplasty. However, advances in bearings have expanded prosthetic head options from traditional sizes of 22, 26, 28, and 32 mm to diameters as large as 60 mm. Large heads reportedly enhance stability owing to increased range of motion before impingement and increased jump distance to subluxation. Available larger diameter material combinations include metal-or ceramic-on-highly crosslinked polyethylene and metal-on-metal, each with distinct advantages and disadvantages. Questions/purposes We sought to determine (1) if using larger diameter heads has lowered our dislocation rate; and (2) how closely an anatomic metal-on-metal bearing with diameters to 60 mm replicates native femoral head size. Methods We retrospectively reviewed 2020 primary arthroplasties performed with large heads (C 36 mm) in 1748 patients and noted dislocation incidence. In a prospective subset of 89 cases using anatomic heads, native femoral head diameter was measured intraoperatively with calipers by an independent observer and later compared with implanted size. Results One dislocation has occurred in 2020 hips for an incidence of 0.05%. The prosthetic head averaged 0.7 mm larger than the native head with 68 of 89 (76%) reconstructed to within ± 2 mm of native size. Conclusions Larger diameter heads have contributed to lower dislocation rates and large-diameter metal-on-metal articulation can provide close anatomic restoration in primary THA.

“…The surgical approach may be extended for additional exposure if necessary. The reported dislocation rate with this approach has been reported as 0 to 2% [3,6,7,11,14], with an overall dislocation rate of 0.55% [13]. So-called ''hip precautions'' are not necessary when utilizing this approach for primary arthroplasty [17].…”

Section: Anterolateral Approach (Supine Position)mentioning

confidence: 99%

Acetabular Orientation: Anterolateral Approach in the Supine Position

Austin¹,

Rothman²

2009

The anterolateral approach in the supine position provides excellent visualization of the acetabulum. The main advantage of the approach, a low dislocation rate, has been demonstrated in the literature, while the purported disadvantage of abductor dysfunction has not been clearly delineated in the literature. The technique requires meticulous attention to preservation of the gluteus medius and minimus tendons. Impingement and dislocation are avoided by careful attention to the preparation of acetabulum, critical assessment of the implanted components, and intraoperative trialing. Leg lengths are assessed through direct palpation of the malleoli. Routine use of postoperative hip precautions is not necessary when this approach is utilized. The anterolateral approach in the supine position allows for a reproducible result with a low dislocation rate. Level of Evidence: Level V, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.