The mid-long term results of reconstructional cage and morselized allografts combined application for the Paprosky type III acetabular bone defects in revision hip arthroplasty.

BACKGROUND: Severe acetabular bone defects is a complex problem in revision hip arthroplasty, cage is one of the reconstruction options. The purpose of this study is to report the mid-long term clinical and radiographic results of Paprosky type III acetabular bone defects revised with reconstructional cage and morselized allogeneic cancellous bone graft without impaction. METHODS: We retrospectively analyzed 28 patients who underwent revision hip arthroplasty with reconstructional cage and allogeneic cancellous bone graft between January 2007 and January 2016. There were 13 Paprosky type IIIA bone defect patients and 15 Paprosky type IIIB bone defect patients and 4 patients of the 15 were also with pelvic discontinuity. Clinical assessment included Harris Hip Score (HHS) and Short Form-12 (SF-12). Radiographic assessment included center of rotation, cage migration, and bone graft incorporation. RESULTS: All patients were followed up with a mean follow-up of 79.5 months (range 38-141), HHS improved from 31.4 (13-43) points preoperatively to 84.6 (55-94) points at last follow-up and SF-12 also improved significantly. There was 1 re-revision for the cage loosening and screw breakage at 61 months after surgery, and 2 patients had nonprogressive radiolucency in zone III and the junction of zone II and zone III at the bone implant interface. CONCLUSION: The reconstructional cage combining with morselized allografts without impaction achieves a good result with a high complete allograft incorporation rate in Paprosky type III acetabular bone defects.

Short-term follow-up of anterior and posterior both column fractures of acetabulum managed through both column plating.

OBJECTIVE: To evaluate the results of short-term follow-up of patients of both column acetabular fractures managed through anterior and posterior column plating. INTRODUCTION: Both column acetabular fractures are challenging articular injuries. Majority of them are treated operatively. The concept of "secondary congruence" was introduced by Letournel. Despite this, biomechanical data on secondary congruence indicate that nonoperative treatment leads to an increase in peak pressures in the supraacetabular region with the potential risk of developing posttraumatic degenerative osteoarthritis. Operative management is therefore justified. METHODOLOGY: A cohort of 10 patients having both column (anterior and posterior) acetabular fractures managed using bicolumnar plating between January 2016 and December 2017 were enrolled in the study and were analyzed during follow-up period. RESULTS: In total, 80% of the patients had excellent to good result. Average postoperative score was 85.7. Assessment was done using modified Harris Hip score.

Acetabular reconstruction with the Kerboull-type plate at mid-term follow-up: survivorship analysis and prognostic factors for loosening.

INTRODUCTION: Successful reconstruction during total hip arthroplasty for acetabular bone defects remains challenging. The purpose of our study was to evaluate clinical and radiographic results and performed a survivorship analysis for patients with acetabular bone loss undergoing total hip arthroplasty (THA) or revision THA using Kerboull-type acetabular reinforcement device(KT plate). Additionally, some independent prognostic factors for radiographic failure were identified. METHODS: A retrospective cohort study was conducted. Thirty patients (36 hips) were available for follow-up examination between 1997 and 2012, with a mean follow-up period of 10 years. We evaluated clinical and radiographic results. The mean patient age at the time of the operation was 66 years. RESULTS: Failure occurred in 6 cases, and further revisions were required for 2 hips. With failure for any reason as an endpoint, the cumulative survival at 10 years was 85%. Survival analysis at 10 years with failure as the endpoint revealed that the inclination angle of the KT plate ≤ 45° group showed higher survivorship than the inclination angle > 45° group (95.8 vs. 63.6%, P = 0.0047). CONCLUSIONS: With a mean follow-up of 10 years, the clinical and radiographic outcomes were satisfactory. While this study group was small, the results suggest that prosthesis longevity may be improved by setting the inclination angle of this reinforcement device at ≤ 45°.

[Biological downsizing : Acetabular defect reconstruction in revision total hip arthroplasty]. / Biologisches Downsizing : Azetabuläre Knochendefekte in der Hüftrevisionsendoprothetik.

BACKGROUND: Periacetabular bony defects remain a great challenge in revision total hip arthroplasty. After assessment and classification of the defect and selection of a suitable implant the primary stable fixation and sufficient biological reconstitution of a sustainable bone stock are essential for long term success in acetabular revision surgery. Biological defect reconstruction aims for the down-sizing of periacetabular defects for later revision surgeries. TECHNIQUE: In the field of biological augmentation several methods are currently available. Autologous transplants feature a profound osseointegrative capacity. However, limitations such as volume restrictions and secondary complications at the donor site have to be considered. Structural allografts show little weight bearing potential in the long term and high failure rates. In clinical practice, the usage of spongious chips implanted via impaction bone grafting technique in combination with antiprotrusio cages for the management of contained defects have shown promising long time results. Nevertheless, when dealing with craniolateral acetabular and dorsal column defects, the additional implantation of macroporous metal implants or augments should be considered since biological augmentation has shown little clinical success in these particular cases. PROSPECT: This article provides an overview of the current clinically available biological augmentation methods of peri-acetabular defects. Due to the limitations of autologous and allogeneic bone transplants in terms of size and availability, the emerging field of innovative implantable tissue engineering constructs gains interest and will also be discussed in this article.

[Use of dual mobility cups for revision hip arthroplasty]. / Einsatz von Dual-Mobility-Pfannen beim Hüftprothesenwechsel.

The dual mobility cup (DMC) is an increasingly important tool not only in primary but also in revision total hip arthroplasty to prevent dislocation and eventually reduce postoperative complication rates. Various studies have shown survival rates with DMCs of up to 100% with an average dislocation rate of less than 1.5% after primary hip arthroplasty and a follow-up of 10 years. In revision surgery, survival rates of up to 99% were reported with dislocation rates between 0 and 10% after an average of 5 years after implantation. This article is intended to provide an overview of the principle and function of DMCs. Furthermore, indications as well as complications are presented.

[Treatment of acetabular defects with the trabecular metal revision system]. / Defektadaptierte azetabuläre Versorgung mit der Trabecular-Metal-Technologie.

BACKGROUND: The results after acetabular component revision are very heterogeneous, irrespective of the use of established or new components. This could be due to a lack of treatment standards for new revision components. The Trabecular Metal™ (TM) revision system, through its modularity, allows for an individual intraoperative reconstruction of the acetabular defect with a single implant system. It was the aim of this study to investigate the results of acetabular revision with the TMT system taking into consideration the utilized components and the acetabular defect. METHODS: A total of 200 consecutive isolated revisions of the acetabular component from 2010 until 2012 were retrospectively analyzed from our institutional database. Of the 200 cases, 114 revisions were performed with a combination of different TMT components (wedge and cup, cup and cage). Aseptic cup failure and revision for any reason were the defined endpoints of this study. The acetabular defects were graded according to the Paprosky classification. RESULTS: The average patient age was 63.6 ± 14.8 years (range 32-85 years) and the average follow-up was 5.3 ± 0.7 years. The overall revision rate, independent of the utilized components, was 4.4% and the revision rate for aseptic failure of the acetabular component was 2.6%. The revision rate for aseptic loosening for Paprosky type I and II defects was 0% and Paprosky type III and IV defects was 12%. CONCLUSIONS: The modular TMT system shows low revision rates. The modularity of the system allows for a safe and intraoperative adaptation to the individual acetabular defect without the need for extensive preoperative imaging or custom-made implants.

[Partial exchange in total hip arthroplasty : What can we combine?] / Gelenkteilwechsel in der Hüftarthroplastik : Was dürfen wir kombinieren?

BACKGROUND: In case of hip revision arthroplasty, one component (cup/stem) is often well fixed and does not need to be exchanged. The newly implanted component needs to be compatible with the well-fixed implant. The combination of implants from different companies leads to "mix and match" or even mismatch between the implants. OBJECTIVES AND METHODS: The objective of this work was to describe possible combinations including their specifications that need to be considered in partial exchange of hip prostheses. For this purpose the literature, surgical techniques of companies and judgements concerning this topic were analysed and our own results and experiences were included. RESULTS AND CONCLUSIONS: Partial revision arthroplasty can be challenging and needs to be planned in detail. In case of isolated cup or inlay revision with exchange of a modular head the cone of the stem needs to be identified. A ceramic head may be used in revision with a titanium sleeve even from a different company as long as they are compatible. Patients however need to give their informed consent for this mix and match procedure. This procedure is done frequently and good study results support this, however from a juristic point of view a definite recommendation cannot be given. If the inlay of a cup is replaced, the original inlay should be used. If this is not available anymore, it can be manufactured as a special product in many cases. If this is also not possible, an inlay can also be cemented into a well-fixed cup. Biomechanical and clinical studies support this off-label technique. In case of an isolated exchange of the stem with a ceramic inlay that is retained in a well-fixed cup, the revision stem and ceramic head need to be from the same company as the cup. In case of ceramic fracture, a ceramic head with a titanium sleeve should be combined with a PE or ceramic inlay, a metal head or inlay should never be used.

[Treatment of acetabular bone defects in revision hip arthroplasty using the Revisio-System]. / Defektadaptierte Versorgung azetabulärer Knochendefekte mit dem Revisio-System.

BACKGROUND: Many different systems for the management of primary and secondary acetabular defects are available, each with its inherent advantages and disadvantages. The Revisio-System is a press-fit oval mono-block implant that makes a defect-oriented reconstruction and restoration of the center of rotation possible. MATERIAL AND METHODS: In this study, we retrospectively reviewed the outcome of 92 consecutive patients treated with this oval press-fit cup due to periacetabular bone loss. The average follow-up was 58.2 months. Defects were classified according to D'Antonio. There were 39 type II, 38 Type III, and 15 type IV defects. After an average of 4.9 years, the implant survival rate was 94.6% with cup revision as the end point and 89.1% with revision for any reason as the end point. The Harris Hip Score increased from 41.1 preoperatively to 62.3 postoperatively. The mean level of pain measured with the Visual Analogue Scale (VSA) was reduced from 6.9 preoperatively to 3.8 postoperatively. RESULTS: The Revisio-System represents a promising toolbox for defect-orientated reconstruction of acetabular bone loss in revision hip arthroplasty. Our results demonstrate that the implantation of the Revisio-System can result in a good mid-term clinical outcome.

Combination acetabular radiofrequency ablation and cementoplasty using a navigational radiofrequency ablation device and ultrahigh viscosity cement: technical note.

BACKGROUND: Percutaneous radiofrequency ablation and cementoplasty is an alternative palliative therapy for painful metastases involving axial load-bearing bones. This technical report describes the use of a navigational radiofrequency probe to ablate acetabular metastases from an anterior approach followed by instillation of ultrahigh viscosity cement under CT-fluoroscopic guidance. MATERIALS AND METHODS: The tumor ablation databases of two institutions were retrospectively reviewed to identify patients who underwent combination acetabular radiofrequency ablation and cementoplasty using the STAR Tumor Ablation and StabiliT Vertebral Augmentation Systems (DFINE; San Jose, CA). Pre-procedure acetabular tumor volume was measured on cross-sectional imaging. Pre- and post-procedure pain scores were measured using the Numeric Rating Scale (10-point scale) and compared. Partial pain improvement was categorically defined as ≥ 2-point pain score reduction. Patients were evaluated for evidence of immediate complications. Electronic medical records were reviewed for evidence of delayed complications. RESULTS: During the study period, 12 patients with acetabular metastases were treated. The median tumor volume was 54.3 mL (range, 28.3-109.8 mL). Pre- and post-procedure pain scores were obtained from 92% (11/12) of the cohort. The median pre-procedure pain score was 8 (range, 3-10). Post-procedure pain scores were obtained 7 days (82%; 9/11), 11 days (9.1%; 1/11) or 21 days (9.1%; 1/11) after treatment. The median post-treatment pain score was 3 (range, 1-8), a statistically significant difference compared with pre-treatment (P = 0.002). Categorically, 73% (8/11) of patients reported partial pain relief after treatment. No immediate symptomatic complications occurred. Three patients (25%; 3/12) were discharged to hospice within 1 week of treatment. No delayed complications occurred in the remaining 75% (9/12) of patients during median clinical follow-up of 62 days (range, 14-178 days). CONCLUSIONS: Palliative percutaneous acetabular radiofrequency ablation and cementoplasty can be feasibly performed from an anterior approach using a navigational ablation probe and ultrahigh viscosity cement instilled under CT-fluoroscopic guidance.

Phosphocalcium ceramics are efficient in the management of severe acetabular loss in revision hip arthroplasties. A 22 cases long-term follow-up study.

Management of bone loss in revision total hip replacement remains a challenge. To eliminate any immunological or infectious problem and so to try to improve the long-term results obtained with allografts, the authors used synthetic ceramics as bone substitutes since 1995. We reviewed 13 of the patients of our study, we previously reported in 2005 (Schwartz and Bordei in Eur J Orthop Surg Traumatol 15: 191 2005), which was a prospective cohort of thirty-two cases of acetabular revision reconstruction, with a mean follow-up of 14.4 years yet (from 9 to 16 years). Clinical results were assessed according to Oxford scale and Postel and Merle d'Aubigne (PMA) scale. Since 2005, no specific complications were noted. The average PMA functional hip score was 14.9 (vs. 9.2 before revision) at follow-up over 9 years. Nine patients still alive in 2013 were seen again by a surgeon, which was not the operator, with a mean follow-up of 15.3 years: Their Oxford average score was 40.3. Radiological assessment affirmed a good integration of the substitutes in bone without any edging in all cases. A progressive invasion of the ceramics by bone can be seen on the X-ray. We conclude that about 15 years of average delay, which is a significant follow-up in orthopedic surgery, the outcomes without specific complications are satisfactory and allow one to go with these materials in total hip revision surgery.

[Acetabulum injuries in infancy and childhood]. / Acetabulumverletzungen im Kleinkindes--und Kindesalter.

In this article, the anatomical and morphological features of the acetabulum in infancy and childhood are presented. The pathology and treatment of older children and adolescents is deliberately not covered, because the fracture morphology and treatment of patients aged 13 to 15 years is based on the criteria of adult medicine. Especially in the younger child, the anatomical differences are of particular importance. The younger the child is, the more difficult the diagnosis. Therefore today, MRI examinations should be generous used, even if anesthesia is necessary. If the injured child is hemodynamic stable, anesthesia can be electively used for a more complex diagnosis. Acetabular fractures are particularly problematic in infancy because even with optimal treatment and perfect reduction growth disturbances can occur. These manifest as so-called secondary dysplasia. During treatment, care should be taken to ensure that a surgical team having experience with the infant and juvenile skeleton is available and that appropriate implants are available.

Transverse + posterior wall fractures of the acetabulum: epidemiology, operative management and long-term results.

UNLABELLED: PURPOUSE OF THE STUDY: Associated transverse and posterior wall fractures account for approximately 20% of all acetabular fractures. To asses the risk of these concommitant bone injuries on early joint failure despite a high rate of postoperative congruency. MATERIAL: The analysis of 104 surgically treated patients with associated transverse and posterior wall fractures showed that more than half of these patients had associated injuries. The mean age was 35 years, and > 75% of these patients were male. A high energy trauma was the trauma mechanism in 94.2%. The mean ISS was 26.3 points. The majority of patients showed a juxta- or transtectal fracture line. The mean articular fracture displacement was 13.5 mm. 87.5% of the patients showed a femoral head dislocation. An acetabular roof comminution was present in 16.3%. 20.2% of patients received a fracture related preoperative nerve injury to the sciatic nerve. METHODS: Osteosynthesis was performed 9.9 days after trauma. The Kocher-Langenbeck approach was used in > 90% for stabilization with a combination of plate and screw fixation in 71.1%. The mean operative time was 190 minutes with a blood loss of 855 ml. Postoperatively the hip joint was congruent in 90.3% with anatomical or near-anatomical joint reconstruction in > 90%. Iatrogenic nerve injury occurred in 12 patients (8.9%). RESULTS: 67 patients (67.7%) could be followed after a mean of 42.7 months. The average subjective Visual Analog Scale pain score was 42.7. Mild or no pain was seen in 58.2%. The mean Merle d'Aubigné score was 15.4 with 56.7% of patients having a functionally perfect or good result. 52.2% had no post-traumatic osteoarthritic changes of their hip joint. A joint failure was diagnosed in 32.8% of the patients. Analyzing only patients with anatomically reconstructed hip joints, patients showed comparable results with 61.3% having no or mild pain and 59.2% a good or excellent functional result. Posttraumatic arthrotic changes occur in only 26.5% of these patients. A joint failure was present in 32.7%. In this group, a joint failure was significantly more likely to be present with an additional acetabular comminution zone. CONCLUSION: Associated transverse and posterior wall fractures have a significant risk of early joint failure despite a high rate of postoperative congruency.

Traditional three-dimensional printing technology versus three-dimensional printing mirror model technology in the treatment of isolated acetabular fractures: a retrospective analysis.

OBJECTIVE: This study was performed to compare the clinical outcomes of traditional three-dimensional (3D) printing technology and 3D printing mirror model technology in the treatment of isolated acetabular fractures. METHODS: Prospectively maintained databases were reviewed to retrospectively compare patients with an isolated acetabular fracture who were treated with traditional 3D printing technology (Group T) or 3D printing mirror model technology (Group M) from 2011 to 2017. In total, 146 advanced-age patients (146 hips) with an isolated acetabular fracture (Group T, n = 72; Group M, n = 74) were assessed for a mean follow-up period of 29 months (range, 24-34 months). The primary endpoint was the postoperative Harris hip score (HHS). The secondary endpoints were the operation time, intraoperative blood loss, fluoroscopy screening time, fracture reduction quality, and incidence of postoperative complications at the final follow-up. RESULTS: The HHS, operation time, intraoperative blood loss, fluoroscopy screening time, and incidence of postoperative complications were significantly different between the groups, with Group M showing superior clinical outcomes. CONCLUSION: In patients with an isolated acetabular fracture, 3D printing mirror model technology might lead to more accurate and efficient treatment than traditional 3D printing technology.

Surgical Treatment of Pelvic Discontinuity: A Systematic Review and Meta-Analysis.

BACKGROUND: Pelvic discontinuity is a rare condition that is treated with a range of implant constructs. However, surgical failure rates are high, and outcome data are inconsistent. It is therefore difficult to gain a clear picture of whether recently developed constructs (antiprotrusio cage [APC], cup-cage, custom triflange, and porous metal) provide better outcomes in terms of mechanical failure and complications in the short to long terms. This study investigated the failure and complication rates associated with cage constructs and porous metal technologies. METHODS: A systematic review and meta-analysis were performed according to the Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines to evaluate the studies showing pelvic discontinuity in revision total hip arthroplasty. Data retrieved included the intervention performed, length of follow-up, mechanical failure, and other complication rates (dislocation, infection, neurological, loosening, migration). Study quality was assessed with the Methodological Index for Non-Randomized Studies (MINORS) instrument. Pooled mechanical failure and complication rates were calculated using MetaXL 5.3. RESULTS: None of the included 30 articles (n = 585 hips) were of high quality. The meta-analyses revealed a mechanical failure rate of 14% for all constructs combined. Custom triflange (5%) and cup-cage (7%) had the lowest mechanical failure rates compared with the commonly used APC (25%) and porous metal (12%). The overall other complication rate was 28%, with cup-cage lower at 21% compared with APC (34%) and custom triflange (28%). Long-term evidence investigating both interventions and porous metal technology is limited. CONCLUSIONS: Mechanical failure rates for cup-cage and custom triflange were lowest. The other complication rate for cup-cage was lower than the pooled average. The study quality was limited, indicating a need for better studies and/or a registry. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Role of Cages in Revision Arthroplasty of the Acetabulum.

➤ The outcome of acetabular revision is heavily influenced by the degree of associated bone loss.➤ Uncemented hemispherical acetabular components can be used in the majority of acetabular revisions, although occasionally the degree of bone loss precludes the stability of the hemispherical component at the correct anatomic level or there is minimal bleeding host bone left for biologic fixation.➤ Massive acetabular bone loss resulting in the need for bone grafts or highly porous augments involving more than half of the acetabulum is one of the main indications for the use of cages.➤ The cup-cage reconstruction is based on bone-grafting the deficient acetabulum and securing a hemispherical, highly porous metal component with multiple screws to bridge the discontinuity and off-loading the hemispherical component with a titanium cage spanning from ischium to ilium.➤ In addition to managing pelvic discontinuities, the cup-cage construct can also be used in hips without discontinuity as the hemispherical, highly porous metal component is used to restore bone stock.➤ In situations in which there is not enough bleeding host bone to secure a hemispherical component, a highly porous metal augment can be used to address the osseous deficiency. The augment is also protected with a cage to assist bone ingrowth.

[Surgical Treatment of Acetabulum Fractures with a New Acetabulum Butterfly Plate]. / Operative Versorgung von Azetabulumfrakturen mit der neuen Azetabulumflügelplatte.

Introduction: There have been significant increases in the number of acetabular fractures in elderly patients with primarily ventral pathology and medial protrusion of the femoral head. We have developed the "acetabulum wing plate", which is designed to facilitate repositioning, with its anatomically precontoured structure, and which offers full support of the quadrilateral surface, thus counteracting the force of the femoral head pushing inwards. Conventional plate osteosynthesis only provides insufficient support to the medial surface. After a successful series of biomechanical tests, we now report a clinical case series. Material and Methods: Between April 2012 and August 2013, a total of twelve patients underwent plate osteosynthesis using the precontoured plate described above. The patients (ten male, two female) were aged between 45 and 87 years, the average age being 62.5 years. We were able to perform all osteosynthesis with the modified Stoppa approach, in combination with the first window of the ilioinguinal approach (according to Letournel). In most patients, the plate was applied without complications, In some patients, it even supported repositioning. In six patients, the fractures were of the anterior collum and six fractures were fractures of both colla. The mean time span of follow-up was 13.1 months, the minimum being 4.5 and the maximum 23 months. Results: In most patients, the intra- and postoperative computed tomographic scans showed anatomically correct placement of the plate, thus confirming the correct repositioning of the bone. Routine follow-ups are part of the hospital's postsurgical care system for acetabular fractures; these revealed no secondary dislocation or loosening of the plate. The radiological examination showed consolidation of the fractures after a mean period of twelve weeks. A full year after the initial procedure, no implant-specific complications were observed. Revision surgery was necessary in one patient due to bleeding five days after surgery. In another patient, necrosis of the femoral head necessitated total hip replacement ten weeks after the first surgical intervention. In summary, the concept of the plate proved to be successful in its first case series. Summary: In spite of increasing surgical expertise and the refinements of standard approaches, there is a recognisable shift in acetabular fractures from mainly posterior fracture patterns to fractures of the anterior column. The new acetabulum wing plate takes these factors into account and is an implant designed to address the anterior aspects of the acetabulum. The outcome of the first application is promising and the acetabulum wing plate produces satisfactory results in our patients.

Percutaneous Anterior Column Fixation for Acetabulum Fractures, Does It Have to Be Difficult?-The New Axial Pedicle View of the Anterior Column for Percutaneous Fixation.

Anterior column percutaneous screw fixation can be challenging. The purpose of this new technique is to offer a rapid, simple, and safe method to place an anterior screw. The authors used a 3-dimensional reconstruction simulation, cadaver study, and a clinical case series to demonstrate this new alternative to standard previously described techniques.