- Email: [email protected]
Simplifying the Hip-Spine Relationship for Total Hip Arthroplasty: When Do I Use Dual-Mobility and Why Does It Work?
The Journal of Arthroplasty 34 (2019) S74eS75
Contents lists available at ScienceDirect
The Journal of Arthroplasty journal homepage: www.arthroplastyjournal.org
2018 AAHKS Annual Meeting Symposium
Simplifying the Hip-Spine Relationship for Total Hip Arthroplasty: When Do I Use Dual-Mobility and Why Does It Work? Matthew P. Abdel, MD * Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN
a r t i c l e i n f o
a b s t r a c t
Article history: Received 7 January 2019 Accepted 9 January 2019 Available online 18 January 2019
Recent data indicate that the contemporary prevalence of dislocation after primary total hip arthroplasty is up to 5- to 10-fold greater in those patients with spinal deformities that lead to stiffness and/or significant pelvic tilt. Moreover, the interplay between the hip and spine is complex, dynamic, and changes over the lifetime of a patient. Finally, the interplay is not fully understood. As such, consideration should be given to the use of dual-mobility constructs in this cohort of patients given the increased effective head size, combined with the dual articulation before hard impingement. © 2019 Elsevier Inc. All rights reserved.
Keywords: primary total hip arthroplasty spine pelvic tilt stiffness dislocation
The interplay between the hip and spine is complex, dynamic, and changes over the lifetime of a patient. In addition, the interplay is not fully understood. When considering a total hip arthroplasty (THA) in a patient with a spinal deformity, there are 3 main considerations. Foremost, the surgeon needs to understand if the deformity is stiff or flexible. Thereafter, it is important to understand if the patient has lumbar lordosis or a flatback deformity. Finally, it is important to fundamentally understand the neuromuscular control patients have over their spine and hip. The aforementioned 3 considerations allow for individualized assessment of pelvic tilt and spinal stiffness in each patient. In general, when patients have anterior pelvic tilt due to their spinal deformity, the surgeon may consider increased acetabular anteversion at the time of THA. This is particularly true if the patient has a stiff spine. On the other hand, if the patient has posterior pelvic tilt, their anteversion target at the time of THA should be decreased, particularly if they have a flexible spine. However, if a patient has a stiff spine, and posterior pelvic tilt, then standard anteversion targets should be applied.
Investigation was performed at the Mayo Clinic, Rochester, MN. One or more of the authors of this paper have disclosed potential or pertinent conflicts of interest, which may include receipt of payment, either direct or indirect, institutional support, or association with an entity in the biomedical field which may be perceived to have potential conflict of interest with this work. For full disclosure statements refer to https://doi.org/10.1016/j.arth.2019.01.021. * Reprint requests: Matthew P. Abdel, MD, Mayo Clinic, 200 First Street S.W. Rochester, MN 55905. https://doi.org/10.1016/j.arth.2019.01.021 0883-5403/© 2019 Elsevier Inc. All rights reserved.
The natural question then arises: is that enough to mitigate the risk of the dislocation? The clear answer is no for several reasons. Foremost, the aforementioned oversimplified algorithm ignores the fact that changes to the spine occur over time. Patients can develop deformities later in life and may indeed have instrumented and noninstrumented fusions well after they have a THA. Second, it is impossible to predict the innumerable activities that patients participate in and thus the innumerable combinations of hip positions. Finally, we have no way to accurately, reliably, and efficiently determine the true neuromuscular control patients have over their hips when participating in dynamic activities. Given the aforementioned information, dual-mobility constructs at the time of index THA are a viable option in the subset of patients who have stiff spines either due to pathologic processes or surgical fusions (whether instrumented or noninstrumented). Benefits of Dual-Mobility Constructs The author (M.P.A.) had previously illustrated the benefits of using dual-mobility constructs in the revision [1,2] and conversion [3] settings. Given that the dislocation rate after primary THA in patients with spine fusions is similar to that of patients undergoing revision THAs, several of the methodologies used to mitigate the risk of dislocation in the revision setting can be applied to this patient cohort. The main benefits of a dual-mobility construct are twofold. First, a larger effective head size is achieved, improving the head-to-neck ratio and jump distance, and thus minimizing the risk of
M.P. Abdel / The Journal of Arthroplasty 34 (2019) S74eS75
dislocation. Second, the dual articulations allow a greater overall range of motion before impingement and dislocation. While these benefits of dual-mobility constructs certainly help mitigate the risk of dislocation, pristine surgical technique, accurate acetabular component positioning, and refined femoral component positioning are all essential as well.
S75
postoperative dislocation. The larger mean effective head size, combined with the dual articulations, help mitigate the risk of dislocation. Such a solution is essential given the fact that spine deformities develop and change over time combined with the fact it is impossible to fully predict the innumerable high-risk positions patients place their hip.
Cons The author (M.P.A.) had previously described the potential concerns with dual-mobility constructs [4]. These include the theoretical risk of adverse local tissue reactions if a cobalt-chrome liner is used with a titanium acetabular component and intraprosthetic dislocations. However, the benefits of substantially reducing the rate of complications, namely dislocations, far outweigh the theoretical concerns. Conclusion Dual-mobility constructs are an excellent option for those patients with spinal pathologies given their very high risk of
References [1] Abdel MP. Dual-mobility constructs in revision total hip arthroplasties. J Arthroplasty 2018;33:1328e30. [2] Hartzler MA, Abdel MP, Sculco PK, Taunton MJ, Pagnano MW, Hanssen AD. Otto Aufranc Award: dual-mobility constructs in revision THA reduced dislocation, rerevision, and reoperation compared with large femoral heads. Clin Orthop Rel Res 2018;476:293e301. [3] Chalmers BP, Ledford CK, Taunton MJ, Sierra RJ, Lewallen DG, Trousdale RT. Cementation of a dual mobility construct in recurrently dislocating and high risk patients undergoing revision total arthroplasty. J Arthroplasty 2018;33: 1501e6. [4] Chalmers BP, Perry KI, Hanssen AD, Pagnano MW, Abdel MP. Conversion of hip hemiarthroplasty to total hip arthroplasty utilizing a dual-mobility construct compared with large femoral heads. J Arthroplasty 2017;32: 3071e5.
Contents lists available at ScienceDirect
The Journal of Arthroplasty journal homepage: www.arthroplastyjournal.org
2018 AAHKS Annual Meeting Symposium
Simplifying the Hip-Spine Relationship for Total Hip Arthroplasty: When Do I Use Dual-Mobility and Why Does It Work? Matthew P. Abdel, MD * Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN
a r t i c l e i n f o
a b s t r a c t
Article history: Received 7 January 2019 Accepted 9 January 2019 Available online 18 January 2019
Recent data indicate that the contemporary prevalence of dislocation after primary total hip arthroplasty is up to 5- to 10-fold greater in those patients with spinal deformities that lead to stiffness and/or significant pelvic tilt. Moreover, the interplay between the hip and spine is complex, dynamic, and changes over the lifetime of a patient. Finally, the interplay is not fully understood. As such, consideration should be given to the use of dual-mobility constructs in this cohort of patients given the increased effective head size, combined with the dual articulation before hard impingement. © 2019 Elsevier Inc. All rights reserved.
Keywords: primary total hip arthroplasty spine pelvic tilt stiffness dislocation
The interplay between the hip and spine is complex, dynamic, and changes over the lifetime of a patient. In addition, the interplay is not fully understood. When considering a total hip arthroplasty (THA) in a patient with a spinal deformity, there are 3 main considerations. Foremost, the surgeon needs to understand if the deformity is stiff or flexible. Thereafter, it is important to understand if the patient has lumbar lordosis or a flatback deformity. Finally, it is important to fundamentally understand the neuromuscular control patients have over their spine and hip. The aforementioned 3 considerations allow for individualized assessment of pelvic tilt and spinal stiffness in each patient. In general, when patients have anterior pelvic tilt due to their spinal deformity, the surgeon may consider increased acetabular anteversion at the time of THA. This is particularly true if the patient has a stiff spine. On the other hand, if the patient has posterior pelvic tilt, their anteversion target at the time of THA should be decreased, particularly if they have a flexible spine. However, if a patient has a stiff spine, and posterior pelvic tilt, then standard anteversion targets should be applied.
Investigation was performed at the Mayo Clinic, Rochester, MN. One or more of the authors of this paper have disclosed potential or pertinent conflicts of interest, which may include receipt of payment, either direct or indirect, institutional support, or association with an entity in the biomedical field which may be perceived to have potential conflict of interest with this work. For full disclosure statements refer to https://doi.org/10.1016/j.arth.2019.01.021. * Reprint requests: Matthew P. Abdel, MD, Mayo Clinic, 200 First Street S.W. Rochester, MN 55905. https://doi.org/10.1016/j.arth.2019.01.021 0883-5403/© 2019 Elsevier Inc. All rights reserved.
The natural question then arises: is that enough to mitigate the risk of the dislocation? The clear answer is no for several reasons. Foremost, the aforementioned oversimplified algorithm ignores the fact that changes to the spine occur over time. Patients can develop deformities later in life and may indeed have instrumented and noninstrumented fusions well after they have a THA. Second, it is impossible to predict the innumerable activities that patients participate in and thus the innumerable combinations of hip positions. Finally, we have no way to accurately, reliably, and efficiently determine the true neuromuscular control patients have over their hips when participating in dynamic activities. Given the aforementioned information, dual-mobility constructs at the time of index THA are a viable option in the subset of patients who have stiff spines either due to pathologic processes or surgical fusions (whether instrumented or noninstrumented). Benefits of Dual-Mobility Constructs The author (M.P.A.) had previously illustrated the benefits of using dual-mobility constructs in the revision [1,2] and conversion [3] settings. Given that the dislocation rate after primary THA in patients with spine fusions is similar to that of patients undergoing revision THAs, several of the methodologies used to mitigate the risk of dislocation in the revision setting can be applied to this patient cohort. The main benefits of a dual-mobility construct are twofold. First, a larger effective head size is achieved, improving the head-to-neck ratio and jump distance, and thus minimizing the risk of
M.P. Abdel / The Journal of Arthroplasty 34 (2019) S74eS75
dislocation. Second, the dual articulations allow a greater overall range of motion before impingement and dislocation. While these benefits of dual-mobility constructs certainly help mitigate the risk of dislocation, pristine surgical technique, accurate acetabular component positioning, and refined femoral component positioning are all essential as well.
S75
postoperative dislocation. The larger mean effective head size, combined with the dual articulations, help mitigate the risk of dislocation. Such a solution is essential given the fact that spine deformities develop and change over time combined with the fact it is impossible to fully predict the innumerable high-risk positions patients place their hip.
Cons The author (M.P.A.) had previously described the potential concerns with dual-mobility constructs [4]. These include the theoretical risk of adverse local tissue reactions if a cobalt-chrome liner is used with a titanium acetabular component and intraprosthetic dislocations. However, the benefits of substantially reducing the rate of complications, namely dislocations, far outweigh the theoretical concerns. Conclusion Dual-mobility constructs are an excellent option for those patients with spinal pathologies given their very high risk of
References [1] Abdel MP. Dual-mobility constructs in revision total hip arthroplasties. J Arthroplasty 2018;33:1328e30. [2] Hartzler MA, Abdel MP, Sculco PK, Taunton MJ, Pagnano MW, Hanssen AD. Otto Aufranc Award: dual-mobility constructs in revision THA reduced dislocation, rerevision, and reoperation compared with large femoral heads. Clin Orthop Rel Res 2018;476:293e301. [3] Chalmers BP, Ledford CK, Taunton MJ, Sierra RJ, Lewallen DG, Trousdale RT. Cementation of a dual mobility construct in recurrently dislocating and high risk patients undergoing revision total arthroplasty. J Arthroplasty 2018;33: 1501e6. [4] Chalmers BP, Perry KI, Hanssen AD, Pagnano MW, Abdel MP. Conversion of hip hemiarthroplasty to total hip arthroplasty utilizing a dual-mobility construct compared with large femoral heads. J Arthroplasty 2017;32: 3071e5.