Treatment of periprosthetic acetabular fractures after previous hemi- or total hip arthroplasty
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Treatment of displaced periprosthetic acetabular fractures in elderly patients. The goal is to stabilize an acetabular fracture independent of the fracture pattern, by inserting the custom-made roof-reinforcement plate and starting early postoperative full weight-bearing mobilization.
Acetabular fracture with or without previous hemi- or total hip arthroplasty.
Non-displaced acetabular fractures.
Watson-Jones approach to provide accessibility to the anterior and supraacetabular part of the iliac bone. Angle-stable positioning of the roof-reinforcement plate without any fracture reduction. Cementing a polyethylene cup into the metal plate and restoring prosthetic femoral components.
Full weight-bearing mobilization within the first 10 days after surgery. In cases of two column fractures, partial weight-bearing is recommended.
Of 7 patients with periprosthetic acetabular fracture, 5 were available for follow-up at 3, 6, 6, 15, and 24 months postoperatively. No complications were recognized and all fractures showed bony consolidation. Early postoperative mobilization was started within the first 10 days. All patients except one reached their preinjury mobility level. This individual and novel implant is custom made for displaced acetabular and periprosthetic fractures in patients with osteopenic bone. It provides a hopeful benefit due to early full weight-bearing mobilization within the first 10 days after surgery.
In case of largely destroyed supraacetabular bone or two-column fractures according to Letournel additional synthesis via an anterior approach might be necessary. In these cases partial weight bearing is recommended.
KeywordsMobilization Osteoporosis Weight-bearing Prosthesis Acetabulum
Behandlung periprothetischer Azetabulumfrakturen nach früherer Hemi- oder Totalhüftendoprothetik
Ziel ist die Behandlung von dislozierten periprothetischen Azetabulumfrakturen bei älteren Patienten. Dabei werden Frakturen des Azetabulums unabhängig vom Frakturmuster durch Einsetzen einer sonderangefertigten Azetabulumabstützpfanne stabilisiert und eine frühe postoperative Mobilisation unter Vollbelastung begonnen.
Azetabulumfraktur mit oder ohne vorherige Hüftendoprothetik.
Zugang nach Watson-Jones, um die Erreichbarkeit des vorderen und supraazetabulären Anteils des Darmbeins zu ermöglichen. Winkelstabile Positionierung der Azetabulumabstützpfanne ohne Frakturreposition. Zementieren einer Polyethylenpfanne in die Metallplatte und Reposition der femoralen Prothesenkomponenten.
Mobilisation unter Vollbelastung innerhalb der ersten 10 Tage nach Operation. In Fällen einer 2‑Pfeiler-Fraktur mit ungenügender Schraubenzahl im stabilen Knochen wird eine Teilbelastung empfohlen.
Von insgesamt 7 Fällen mit periprothetischer Azetabulumfraktur konnten 5 Patienten 3, 6, 6, 15 und 24 Monate postoperativ nachuntersucht werden. Es gab keine nennenswerten Komplikationen. Alle Frakturen zeigten eine knöcherne Konsolidierung. Eine frühe postoperative Mobilisation wurde in den ersten 10 Tagen begonnen und alle Patienten außer einem erreichten ihren ursprünglichen Mobilitätsgrad.
Dieses individuelle, neuartige Implantat ist für dislozierte Azetabulumfrakturen und periprothetische Frakturen bei Patienten mit osteoporotischem Knochen entwickelt worden. Es verspricht hoffnungsvollen Benefit aufgrund der frühen Vollmobilisation innerhalb der ersten 10 Tage nach Operation.
Bei stark zerstörten supraazetabulären Knochen- oder 2-Pfeiler-Frakturen nach Letournel könnte eine zusätzliche Synthese über einen anterioren Zugang notwendig sein. In diesen Fällen wird eine Teilbelastung empfohlen.
SchlüsselwörterMobilisierung Osteoporose Gewichtsbelastung Prothese Azetabulum
Periprosthetic acetabular fractures are severe complications of hemi- (HA) or total hip arthroplasty (THA), and are on the rise in terms of occurrence and recognition [1, 2, 3, 4, 5]. As the function of implants in hip replacement is based on the bone–cement or bone–prosthesis fixation, a fracture that interrupts this fixation presents a challenging situation. In the presence of osteoporosis, even a fall from a standing position can lead to comminuted acetabular fractures with poor prognosis [6, 7, 8, 9, 10]. Different management approaches for stabilization of the acetabular component using dual plates and cages have been described in the literature. In the case of a structural bone defect, allograft treatment has been attempted [11, 12, 13, 14, 15, 16].
The custom-built roof-reinforcement implant
The designed plate by itself has an outer diameter of 50 mm and an inner diameter of 48 mm, which perfectly fits cemented cups of 46 mm. On the cranial side, the cage is extended by a fin to provide sufficient fixation at the intact iliac bone by means of eight angle-stable 3.5-mm screws aimed in different directions. The inner ring is outfitted with another seven holes for 3.5-mm angle-stable screws to provide stabilization for the anterior and posterior column, as well as the acetabular roof. As reaming of the fractured acetabulum is performed up to 52 mm, only one size is necessary for all cases. According to preoperative planning based on CT scans, left and right implants are needed due to the fin of the cage (Fig. 1a, b).
Surgical principle and objective
Treatment of displaced acetabular fractures with or without previous hip replacement in elderly patients. The custom-made acetabulum roof-reinforcement plate maintains stable acetabular fixation and allows immediate postoperative mobilization at least in most cases. The implant can be used in periprosthetic acetabular fractures, as well as in the presence of isolated displaced acetabular fractures requiring surgical stabilization and hip arthroplasty.
Compared to the transgluteal approach (Bauer) the classic anterolateral approach (Watson-Jones) is used to provide better access to the anterior and middle supraacetabular part of the iliac bone
In cases with isolated displaced acetabular fractures, the femoral head can be used as autograft after resection in the presence of bone defects
No donor site morbidity
Limited surgery time and limited blood loss
Immediate postoperative mobilization
In case of largely destroyed supraacetabular bone or in case of a two column fracture according to Letournel  additional osteosynthesis might be necessary. In these cases partial weight bearing is recommended
Displaced acetabular fractures without previous hip replacement
Periprosthetic acetabular fracture in HA
Periprosthetic acetabular fracture in THA
Central pelvic dislocation of the femoral head and acetabular protrusion after HA
Age of 65 years or older, depending on bone quality
Pretraumatic mobility dependent on a walker at the most
Non-union of acetabulum fractures after open reduction internal fixation (ORIF)
Poor general health situation
Active or latent infection
Allergy against implant material
Local bone tumors or cysts
Age below 65 years
Non-displaced acetabular fractures
Possible delayed or absent healing of osteoporotic bone
Possible intolerance to the implant
Possible wound healing disturbances, sensibility disturbances, and/or circulation disorders with need for surgical revision
General risks of surgery
Longer surgical time due to cage fixation
Clinical assessment of pelvic stability
Documentation of the patient’s preinjury mobility status
X-ray of the pelvis and hip with AP and oblique views
CT scans of the involved hip in three planes for implant planning
Documentation of the sensibility and circulation of the foot
General preparations for surgery
Instruments and implants
Basic set of surgical instruments for pelvic surgery
Patient-fitted roof-reinforcement plate 3.5 based on preoperative CT scans
Screwdriver hex 2.5 mm with screwdriver bit and helve
Screwdriver star drive T15 with screwdriver bit
Torque limiter 1.5 Nm
3.5-mm hex self-cutting angle-stable screws (L = 10–95 mm)
3.5 mm star drive self-cutting angle-stable screws (L = 10–95 mm)
Anesthesia and positioning
Endotracheal intubation or larynx mask anesthesia
Perioperative single shot of antibiotic (e. g., 2 g cefacolin i. v.)
The hip, iliac crest, and proximal part of the femur are disinfected at once
Passive and active motion should be exercised up to the onset of pain and intensified step-by-step directly after surgery.
Early mobilization with full weight-bearing is started within the first few days with use of a walking aid (crutches, walking frame, cane).
In cases of destruction of the supraacetabular bone or with two column fractures, postoperative CT scan is recommended in order to check the number of screws positioned in stable bone. Postoperative mobilization depends on this information (full or partial weight-bearing).
Errors, hazards, and complications
If the inserted Prolene® mesh graft leaks, a cement outflow into the pelvis is possible.
As joint stability depends on the positioning of the polyethylene cup, increased attention has to be paid during cementing.
In the case of poor positioning of the cemented cup, dislocation of the prosthetic head can occur.
Deep wound infection should be treated by early surgical debridement and appropriate antibiotic treatment.
Incomplete healing of the bone in situations of osteoporosis, partial weight-bearing is recommended.
Surgical repetition is possible. However, after failure of initial surgery, careful reassessment of possible causes of failure is mandatory.
In cases with a fractured acetabular roof, a postoperative CT scan should be performed in order to check screw fixation and stability. Postoperative mobilization with full or partial weight-bearing depends on this information.
Compared to the increasing number of acetabular fractures in the elderly, patients with periprosthetic acetabular fractures are still not very common. Considering a time period of almost 4 years in two level I trauma centers, the authors can report only on 7 patients. Due to the advanced age of the patients, with an average age of 80 years, only 5 were available for FU. Two patients had died in the meantime. In a group of patients with such advanced age it is sometimes difficult to follow-up for a long time period. The authors are aware that this is a limitation of this paper.
In the literature it is reported that the typical acetabulum fracture in osteoporotic bone conditions involves the anterior column associated with a fracture of the quadrilateral plane . This seems to be different with periprosthetic fractures. Only one of the 7 patients showed the described fracture type, whereas among the other 6, a transverse fracture was found in 5 patients and a T-fracture in one. Concerns are reported in the literature regarding stable fixation of the acetabular component, recommending additional cables or plates [5, 10]. The design of the described roof-reinforcement plate is such that all the stability is provided by fixation of the fin of the cage at the intact iliac bone by eight multidirectional angle-stable screws. Additional stability is provided by up to seven angle-stable screws through upper, anterior, and posterior holes of the ring. The stability of fixation allows immediate postoperative full weight-bearing, at least in most cases. Fixation of a fractured anterior column can be performed by anterior screws, but this does not enhance primary stability of the cage. The results of a series of 30 consecutive patients of the same age (average 79 years) suffering from acetabulum fractures without previous prostheses have shown that the stability provided by the fixation described above was sufficient for early full weight-bearing (paper under review). No loosening signs were found in any case. New and modern titanium fixators with multidirectional interlocking screws inserted by a minimally invasive procedure might be an alternative ; however, in the authors’ experience, in periprosthetic fractures the quadrilateral plane is commonly destroyed and associated with a dome fragment of the acetabulum. Furthermore, due to advanced head protrusion in the case of HA, the bone of the quadrilateral plane is thin and of very poor quality, rendering stable fixation even with the new plates difficult.
In summary, this report demonstrates that this custom-built roof-reinforcement plate is a beneficial addition to the treatment spectrum for elderly patients with previous hip replacement, especially for patients with periprosthetic acetabular discontinuity after THA and HA. Early mobilization with full weight-bearing within the first 10 days after surgery can be achieved, at least in most cases. However, short- and long-term results from higher numbers of cases are needed in order to draw conclusions on the mechanical behavior of this custom-made reconstructive implant over time.
Compliance with ethical guidelines
Conflict of interest
Only H. Resch has a pending patent for the novel product, which is broadly relevant to the work. D. Krappinger, P. Moroder, M. Blauth, and J. Becker state that there are no conflicts of interest.
All studies on humans described in the present manuscript were carried out with the approval of the responsible ethics committee and in accordance with national law and the Helsinki Declaration of 1975 (in its current, revised form). Informed consent was obtained from all patients included in studies.
Consent was obtained from all patients identifiable from images or other information within the manuscript. In the case of underage patients, consent was obtained from a parent or legal guardian.
- 16.Ochs BG, Schmid U, Rieth J, Ateschrang A, Weise K, Ochs U (2008) Acetabular bone reconstruction in revision arthroplasty: a comparison of freeze-dried, irradiated and chemically-treated allograft vitalised with autologous marrow versus frozen non-irradiated allograft. J Bone Joint Surg Br 90(9):1164–1171 (Sep)CrossRefPubMedGoogle Scholar
- 21.Matta JM, Mehne DK, Roffi R (1986) Fractures of the acetabulum. Early results of a prospective study. Clin Orthop Relat Res 205:241–250 (Apr)Google Scholar
- 23.Letournel E (1980) Acetabulum fractures: classification and management. Clin Orthop Relat Res 151:81–106 (Sep)Google Scholar
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