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Posterior dislocation of the hinge-post extension in a rotating hinge total knee prosthesis.

Manzano G, Schwarzkopf R - Case Rep Orthop (2013)

Bottom Line: Despite improvements in design, nonmechanical and mechanical complications continue to be a problem.We report a case of isolated disengagement of the rotating hinge mechanism, due to severe flexion gap imbalance, leading to subsequent posterior dislocation of the hinge and anterior knee dislocation, in a patient with a history of multiple total knee arthroplasty revisions.This case suggests the importance of the soft tissue balancing, the adequate patellar tracking, and use of a long cylindrical, minimally tapered rotating stem in hinge arthroplasty to minimize hinge dislocation.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Surgery, Joint Replacement Service, University of California Irvine Medical Center, 101 The City Drive South, Pavilion III, Building 29, Orange, CA 92868, USA.

ABSTRACT
The rotating hinge knee prosthesis is a popular intervention in patients lacking stability with highly constrained total knee arthroplasty. Despite improvements in design, nonmechanical and mechanical complications continue to be a problem. Dislocation of the hinge has been widely described, mainly due to the component fracture. Few reports describe isolated dislocation of the rotating stem. We report a case of isolated disengagement of the rotating hinge mechanism, due to severe flexion gap imbalance, leading to subsequent posterior dislocation of the hinge and anterior knee dislocation, in a patient with a history of multiple total knee arthroplasty revisions. This case suggests the importance of the soft tissue balancing, the adequate patellar tracking, and use of a long cylindrical, minimally tapered rotating stem in hinge arthroplasty to minimize hinge dislocation.

No MeSH data available.


Related in: MedlinePlus

Intraoperative illustrating new tibial hinge insert, hinge pin, and locking pin.
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Related In: Results  -  Collection


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fig3: Intraoperative illustrating new tibial hinge insert, hinge pin, and locking pin.

Mentions: P. K. is an 83-year-old male with a history of multiple health comorbidities and multiple revision right total knee arthroplasty (TKA) with a rotating hinge implant, who presented to our institution's emergency room with progressively worsening right knee pain causing instability and inability to ambulate after sustaining a fall while walking outdoors one month prior. The patient underwent total knee revision surgery 1 year prior at an outside institution where a DePuy S-ROM rotating hinge implant was used. Physical examination was limited due to gross deformity of the right knee. Neurovascular examination was intact with good distal pulses and an ankle brachial index >0.9. Radiographs revealed a posterior dislocation of the hinge post of the right total knee arthroplasty; the post was in close proximity to the location of the popliteal neurovascular structures (Figure 1). A lower extremity CT angiography showed intact vascular structures. Infection workup showed an increase in ESR and CRP however, fluid cultures and cell counts with differential from joint aspirate were unremarkable. Intraoperative findings confirmed a disengaged hinge that dislocated on flexion (Figures 2(a) and 2(b)) and a laterally dislocated patella. The mobile hinge components were removed and replaced with an extra-extra small-size bumper and a 12 mm tibial insert (Figure 3). Extensive lateral release was performed to centralize the laterally dislocated patella and restore proper patella tracking. Intraoperative arc of motion after revision of the hinge components was 0° to 90° against gravity, and no instability could be elicited. Postoperatively, the patient was placed in a hinged brace locked in full extension. At his one-month followup, he was ambulating painlessly with the assistance of a cane and demonstrated flexion up to 100°. Postoperative imaging showed a well-seated implant with no signs of loosening, fracture, dislocation, or wear. The patient was doing well on his 3-month and 1-year followup, ambulating with no assistive devices with good range of motion and no further instability and complications. The patient gave informed consent for the case to be published.


Posterior dislocation of the hinge-post extension in a rotating hinge total knee prosthesis.

Manzano G, Schwarzkopf R - Case Rep Orthop (2013)

Intraoperative illustrating new tibial hinge insert, hinge pin, and locking pin.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3794624&req=5

fig3: Intraoperative illustrating new tibial hinge insert, hinge pin, and locking pin.
Mentions: P. K. is an 83-year-old male with a history of multiple health comorbidities and multiple revision right total knee arthroplasty (TKA) with a rotating hinge implant, who presented to our institution's emergency room with progressively worsening right knee pain causing instability and inability to ambulate after sustaining a fall while walking outdoors one month prior. The patient underwent total knee revision surgery 1 year prior at an outside institution where a DePuy S-ROM rotating hinge implant was used. Physical examination was limited due to gross deformity of the right knee. Neurovascular examination was intact with good distal pulses and an ankle brachial index >0.9. Radiographs revealed a posterior dislocation of the hinge post of the right total knee arthroplasty; the post was in close proximity to the location of the popliteal neurovascular structures (Figure 1). A lower extremity CT angiography showed intact vascular structures. Infection workup showed an increase in ESR and CRP however, fluid cultures and cell counts with differential from joint aspirate were unremarkable. Intraoperative findings confirmed a disengaged hinge that dislocated on flexion (Figures 2(a) and 2(b)) and a laterally dislocated patella. The mobile hinge components were removed and replaced with an extra-extra small-size bumper and a 12 mm tibial insert (Figure 3). Extensive lateral release was performed to centralize the laterally dislocated patella and restore proper patella tracking. Intraoperative arc of motion after revision of the hinge components was 0° to 90° against gravity, and no instability could be elicited. Postoperatively, the patient was placed in a hinged brace locked in full extension. At his one-month followup, he was ambulating painlessly with the assistance of a cane and demonstrated flexion up to 100°. Postoperative imaging showed a well-seated implant with no signs of loosening, fracture, dislocation, or wear. The patient was doing well on his 3-month and 1-year followup, ambulating with no assistive devices with good range of motion and no further instability and complications. The patient gave informed consent for the case to be published.

Bottom Line: Despite improvements in design, nonmechanical and mechanical complications continue to be a problem.We report a case of isolated disengagement of the rotating hinge mechanism, due to severe flexion gap imbalance, leading to subsequent posterior dislocation of the hinge and anterior knee dislocation, in a patient with a history of multiple total knee arthroplasty revisions.This case suggests the importance of the soft tissue balancing, the adequate patellar tracking, and use of a long cylindrical, minimally tapered rotating stem in hinge arthroplasty to minimize hinge dislocation.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Surgery, Joint Replacement Service, University of California Irvine Medical Center, 101 The City Drive South, Pavilion III, Building 29, Orange, CA 92868, USA.

ABSTRACT
The rotating hinge knee prosthesis is a popular intervention in patients lacking stability with highly constrained total knee arthroplasty. Despite improvements in design, nonmechanical and mechanical complications continue to be a problem. Dislocation of the hinge has been widely described, mainly due to the component fracture. Few reports describe isolated dislocation of the rotating stem. We report a case of isolated disengagement of the rotating hinge mechanism, due to severe flexion gap imbalance, leading to subsequent posterior dislocation of the hinge and anterior knee dislocation, in a patient with a history of multiple total knee arthroplasty revisions. This case suggests the importance of the soft tissue balancing, the adequate patellar tracking, and use of a long cylindrical, minimally tapered rotating stem in hinge arthroplasty to minimize hinge dislocation.

No MeSH data available.


Related in: MedlinePlus