THA Revisions Using Impaction Allografting With Mesh Is Durable for Medial but Not Lateral Acetabular Defects

Abstract

Background Most acetabular revisions are managed with cementless hemispherical or elliptical metal implants relying on bone ingrowth. Nonetheless, loss of acetabular bone stock and inability to achieve secure component fixation represent challenges in the setting of revision total hip arthroplasty. Impaction bone grafting (IBG) using allograft represents one option for treatment of this problem. However, cup migration and bone graft resorption are limitations when IBG is used for large segmental defects, and the precise role of IBG as well as the use of mesh (and the kinds of defects for which mesh does not work well) in this setting remains unknown.Questions/purposes We therefore evaluated patients undergoing acetabular revision surgery using IBG and a cemented cup in large bone defects to determine (1) the frequency with which the hip center could be restored in hips with Paprosky 3A and 3B defects and in hips with or without the use of metallic mesh during surgery; (2) survivorship of IBG acetabular-revision reconstructions in patients with severe Paprosky 3A and 3B defects; and (3) risk factors for failure of the reconstruction, including the use of mesh and defect severity (3A versus 3B). Methods Between 1997 and 2009, we performed 226 acetabular revisions using IBG. During that time, indications for using IBG in this setting included Paprosky 3A and 3B defects without pelvic discontinuity. Of these, 204 (90.2%) were available for followup at a minimum of 5 years (mean, 10 years; range, 5-17 years). There were 100 hips with an intraoperative bone defect of Paprosky 3A and 104 with a 3B. Medial or rim acetabular uncontained defects were treated with medial and/or lateral metallic mesh in 142 hips. We determined the postoperative radiological cup position and acetabular reconstruction of the hip center according to Ranawat in both groups. We assessed the appearance of cup loosening and the possible risk factors with regression analysis. Results Mean postoperative acetabular abduction angle and vertical, horizontal, and hip rotation center distances improved (p \ 0.001 in all parameters). Nine hips showed radiological loosening in the group with bone defect 3A and 16 in Group 3B. The survival rate for loosening at 15 years was 83% (95% confidence interval [CI], 71%-95%) for Group 3A and 73% (95% CI, 60%-84%) for Group 3B (p = 0.04). The survivorship for loosening when using mesh or not at 15 years was: no mesh 89% (95% CI, 74%-99%), medial mesh 85% (95% CI, 72%-97%), lateral mesh 80% (95% CI, 67%-91%), and medial and lateral meshes

Use of Trabecular Titanium Implants for Primary Hip Arthroplasty

“…Jest to istotne z uwagi na skłonność do osteolizy dużych przeszczepów kostnych zarówno litych, jak i ubitych [4,5]. Mała ilość przeszczepów kostnych ulega dobrej przebudowie i nie prowadzi do utraty stabilności implantu pomimo wdrożenia częściowego obciążania bezpośrednio po operacji.…”

“…Nie jest to możli-we w przypadku uzupełnienia ubytków wyłącznie za pomocą przeszczepów kostnych. Ich słaba, wyjścio-wa mechaniczna wytrzymałość oraz częściowa liza w procesie wgajania może spowodować destabilizacje implantu przy zbyt szybkim obciążaniu [4,5].…”

“…Niestety często jej ilość lub jakość (zmiany martwicze, skletrotyzacja) nie pozwalają na pełne rozwiązanie problemu. Zastosowanie przeszczepów alogennych ubitych (impaction grafting) lub strukturalnych często daje niezadowalające wy niki [4,5]. Problem nie zawsze rozwiązuje także stosowane w aloplastykach rewizyjnych połączenie przeszczepu kostnego z pierścieniem oporowym [6][7][8].…”

“…This is important in view of the osteolytic propensity of large bone grafts, either solid or compact [4,5]. A small amount of bone graft demonstrates superior ingrowth and does not lead to implant instability de spite the introduction of partial loading immediately after the surgery.…”

“…Unfortunately, this frequently fails to solve the problem completely due to the amount or quality of the bone (necrosis, sclerosis). The use of compact allografts (impaction grafting) or structural grafts in many cases does not provide satisfactory outcomes [4,5]. Likewise, a combination of a bone graft and a resistance ring is also not always an adequate solution [6][7][8].…”