Tracy L Kinsey

University of North Carolina at Chapel Hill, North Carolina, United States

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Publications (23)61 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: For unicompartmental knee arthroplasty (UKA), abnormal loading on the tibiofemoral joint could exacerbate knee osteoarthritis or implant wear. Joint moments are an indirect measure of such loading. However, little is known about knee moments of patients with UKA, tempering enthusiasm for its use. In patients with UKAs performing stair ascent, we (1) determined whether interlimb differences for knee moments are demonstrated, (2) described the knee kinetics of patients with medial and lateral UKAs, and (3) investigated possible factors that might influence the knee abductor moments. In our cross-sectional study, we recruited 26 patients with UKA with nondiseased contralateral limbs who performed stair ascent. Seventeen patients had medial UKAs and nine had lateral UKAs. Paired t-tests and CIs were applied to determine interlimb differences within each UKA group for peak knee moments and times to peak moments. During stair ascent, the medial UKA group displayed greater peak extensor moments for the nondiseased compared to the UKA limb (p = 0.030), whereas the lateral UKA group did not (p = 0.087). For both medial and lateral UKA groups, the UKA limb demonstrated greater internal peak abductor moments (p = 0.005 and 0.013, respectively). Both UKA groups exhibited knee moments similar to those in the literature. Limb dominance and postoperative time were correlated for both UKA groups. Reduced knee extensor moments of limbs with UKA displayed by some participants may indicate less compressive loading on the tibiofemoral joint surfaces, whereas the increased abductor moments suggest increased compression on the medial compartment. These findings suggest UKA knees may not be subjected to excessive loads regardless of the side reconstructed. Level II, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.
    Clinical Orthopaedics and Related Research 07/2013; 472(1). DOI:10.1007/s11999-013-3128-y · 2.88 Impact Factor
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    ABSTRACT: Squeaking is a recognized complication of total hip arthroplasty with ceramic on ceramic bearings but the etiology has not been well identified. We evaluated 183 hips in 148 patients who had undergone ceramic-on-ceramic noncemented total hip arthroplasties at one center between 1997-2007 by standardized telephone interviews and radiographic review. Audible squeaking was reported from 22 hips (12% of 183) of 19 patients. Prevalence of squeaking was associated with younger age; obesity; lateralized cup position; use of beta titanium alloy femoral components and shortened head length options; and higher reported activity level, greater pain, and decreased satisfaction at the time of the interview. Squeaking was described as having little personal significance by most patients. Squeaking might be preventable in part through medialization of the acetabular cup and avoidance of the use of shortened femoral necks.
    The Journal of arthroplasty 03/2013; 28(6). DOI:10.1016/j.arth.2012.10.014 · 2.37 Impact Factor
  • The Journal of Bone and Joint Surgery 02/2013; 95(4):366. DOI:10.2106/JBJS.9504.ebo571 · 4.31 Impact Factor
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    ABSTRACT: The purpose of this article is to determine if individuals with high rather than low femoral offset of a total hip arthroplasty achieve improved hip abductor muscle strength and thus improved their ability to step over an obstacle safely. These outcomes will help surgeons decide whether increasing the femoral offset helps a patient's physical function.
    Orthopedic Clinics of North America 11/2012; 43(5):e48-58. DOI:10.1016/j.ocl.2012.07.008 · 1.70 Impact Factor
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    ABSTRACT: BACKGROUND: Unicompartmental knee arthroplasty (UKA) has long been a treatment option for patients with disease limited primarily to one compartment with small, correctable deformities. However, some surgeons presume that normal kinematics of a lateral compartment UKA are difficult to achieve. Furthermore, it is unclear whether UKA restores normal knee kinematics and interlimb symmetry. QUESTIONS/PURPOSES: We determined knee kinematics exhibited during stair ascent by patients with medial- (MED-UKA) or lateral-UKA (LAT-UKA) and if the knee kinematics of the operated and nonoperated limbs were symmetrical. METHODS: Participants were 17 individuals with MED-UKA and nine with LAT-UKA, all with nondiseased contralateral limbs. For each limb, participants walked up four stairs for five trials while a motion-capture system obtained reflective marker locations. Temporal events were determined by force platform signals. Interlimb symmetry was classified for temporal gait and knee angular kinematics by comparing observed interlimb differences with clinically meaningful differences set at 5% of stride time for temporal variables and 5° for angular variables. The minimum postoperative followup was 6 months (median, 24 months; range, 6-53 months). RESULTS: Neither group demonstrated clinically meaningful mean interlimb differences. However, approximately half of participants of each UKA group displayed asymmetry favoring the operative or nonoperative limb with similar frequency. CONCLUSIONS: Many patients undergoing UKA demonstrate kinematic interlimb symmetry during stair ascent. Interlimb asymmetry may be affected by a variety of factors unrelated to the UKA. CLINICAL RELEVANCE: A MED- or LAT-UKA can potentially restore normal knee function for a demanding task of daily life.
    Clinical Orthopaedics and Related Research 08/2012; 471(1). DOI:10.1007/s11999-012-2522-1 · 2.88 Impact Factor
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    ABSTRACT: Mobile bearing (MB) total knee design has been advocated as a means to enhance the functional characteristics and decrease the wear rates of condylar total knee arthroplasty (TKA). However, it is unclear if these designs achieve these goals. We asked whether function of patients or survivorship would be greater or complications would be lesser in groups of patients with MB compared with fixed bearing (FB) TKA. We also sought to describe retrieval findings. We randomized 507 primary TKAs in 416 eligible patients to receive MB (n = 252) or FB (n = 255) devices from November 2001 to August 2007 (Investigational Device Exemption G000180, registration number NCT00946075). Patients were blinded to treatment allocation. WOMAC Index, SF-12 Health Survey, knee range of motion, and Knee Society scores were collected and compared preoperatively and at 6, 12, and 24 months postoperatively. We recorded device failures and complications until October 2009. Kaplan-Meier survivorship was compared using the log rank test. Twelve retrieved MB devices underwent pathologic analysis. The minimum postoperative time was 2.2 years (mean, 5.9 years; range, 2.2-7.9 years). We found no differences in mean clinical assessment scores or mean score changes from baseline at any postoperative interval through 2 postoperative years. Nineteen of the 252 MB and 13 of the 255 FB knees had undergone revision of any component. Estimated survival at 6 postoperative years was similar for the two devices: 90.1% (95% confidence interval [CI], 84.1-93.9) for MB and 94.2% (95% CI, 90.1-96.6) for FB. Two MB and no FB tibial components were revised for loosening. There was one case of MB insert dislocation. Retrieved MB devices demonstrated no unexpected wear or mechanical device failures. We found no evidence of functional advantage of the MB design. Survivorship was similar, although the study is limited by short duration of followup.
    Clinical Orthopaedics and Related Research 01/2012; 470(1):33-44. DOI:10.1007/s11999-011-2114-5 · 2.88 Impact Factor
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    ABSTRACT: We describe the use of a novel technique for adapting nonmatching tibial inserts into tibial trays in revision total knee arthroplasty. From 1998 to 2003, the senior author performed 7 revision total knee arthroplasty procedures, during which a nonmatching tibial insert was cemented into a tibial tray to retain a well-fixed but incompatible opposite component. Bench tests were undertaken to confirm the stability of cement as a locking mechanism substitute. Three components completed 1 000 000 cycles of loading under simulated physiologic stresses with no evidence of fixation failure. There have been no clinical failures at 18 to 69 months in vivo follow-up (mean, 49 months). This technique provided durable fixation while avoiding host bone damage that might have occurred needlessly had the well-fixed implant been extracted. Level of evidence: level IV therapeutic study, case series.
    The Journal of arthroplasty 04/2011; 27(1):55-9. DOI:10.1016/j.arth.2011.02.013 · 2.37 Impact Factor
  • Ormonde M Mahoney, Tracy Kinsey
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    ABSTRACT: Recently, much attention has been directed to femoral component overhang in total knee arthroplasty. The purposes of this study were to describe the prevalence of femoral component overhang among men and women after total knee arthroplasty, to identify risk factors for overhang, and to determine whether overhang was associated with postoperative knee pain or decreased range of motion. Femoral component overhang was measured intraoperatively during 437 implantations of the same type of total knee arthroplasty prosthesis. The overhang of metal beyond the bone cut edge was measured in millimeters at the midpoint of ten zones after permanent fixation of the implant. Factors predictive of overhanging fit were identified, and the effect of overhang on postoperative pain and flexion was examined. Overhang of >or=3 mm occurred in at least one zone among 40% (seventy-one) of 176 knees in men and 68% (177) of 261 knees in women, most frequently in lateral zones 2 (anterior-distal) and 3 (distal). Female sex, shorter height, and larger femoral component size were highly predictive of greater overhang in multivariate models. Femoral component overhang of >or=3 mm in at least one zone was associated with an almost twofold increased risk of knee pain more severe than occasional or mild at two years after surgery (odds ratio, 1.9; 95% confidence interval, 1.1 to 3.3). In this series, overhang of the femoral component was highly prevalent, occurring more often and with greater severity in women, and the prevalence and magnitude of overhang increased with larger femoral component sizes among both sexes. Femoral component overhang of >or=3 mm approximately doubles the odds of clinically important knee pain two years after total knee arthroplasty.
    The Journal of Bone and Joint Surgery 05/2010; 92(5):1115-21. DOI:10.2106/JBJS.H.00434 · 4.31 Impact Factor
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    The Journal of Bone and Joint Surgery 09/2009; 91 Suppl 5:43-8. DOI:10.2106/JBJS.I.00406 · 4.31 Impact Factor
  • The Journal of Bone and Joint Surgery 09/2009; 91 Suppl 5:23-8. DOI:10.2106/JBJS.I.00363 · 4.31 Impact Factor
  • Ormonde M Mahoney, Tracy L Kinsey, Isao Asayama
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    ABSTRACT: We describe the use of a fully hydroxylapatite-coated long-stem femoral implant in a series of 40 complex revision total hip arthroplasties. All reconstructions involved severe bone loss or malalignment and were accomplished entirely without the use of augmentary bone graft. Outcomes were evaluated at 7 minimum years of follow-up (average, 10.2 years). Three stems were rerevised because of infection, trauma, and loosening with nonunion of a fracture. Bone ingrowth was radiographically evident by one postoperative year in all other cases. There were no cases of subsidence. Stress shielding with thigh pain was seen in one patient. The stem provided immediate stability and excellent long-term fixation in these reconstructions of severely diseased femurs.
    The Journal of arthroplasty 07/2009; 25(3):355-62. DOI:10.1016/j.arth.2009.03.022 · 2.37 Impact Factor
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    ABSTRACT: The purpose of this study was to evaluate the rotational kinematics of a fixed-bearing posteriorly stabilized total knee design in moderate and deep flexion. Three-dimensional kinematics analyses were conducted on 20 knees in 4 weight-bearing positions using 3-dimensional shape-matching techniques. Average maximum skeletal flexion was 138 degrees . Internal tibial rotation was demonstrated in 19 of 20 knees. The average internal tibial rotation in midflexed lunge was 5.5 degrees (-3.8 degrees to 14.1 degrees ) and in maximum flexion kneeling was 4.0 degrees (-3.1 degrees to 10.6 degrees ). Separation of articular surfaces was not identified. In this study, patients with this device demonstrated patterns of rotation similar to those previously reported for both the normal knee and rotating platform designs.
    The Journal of arthroplasty 07/2008; 24(4):641-5. DOI:10.1016/j.arth.2008.03.009 · 2.37 Impact Factor
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    Ormonde M Mahoney, Tracy L Kinsey
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    ABSTRACT: We studied 1030 consecutive cemented primary TKAs performed by the primary author (OMM) using a single-radius, posterior-stabilized total knee prosthesis with 5 years' minimum followup to determine whether an accelerated early failure rate was associated with this design. At 5 to 9.5 postoperative years, 32 knees had been revised at an average of 2.4 postoperative years (range, 0.1-8.2 years) because of infection (11), periprosthetic fracture (10), aseptic loosening (eight), stiffness (two), and late hemarthrosis (one). Four had only the tibial insert revised. One-half of all failures occurred within 1.5 years. The cases of aseptic loosening involved the femoral component in one patient, tibial component in five, and both components in two. With only seven patients (0.7%) having unknown outcomes, the overall failure rate was 4.9 per 1000 person-years for the study period. The Kaplan-Meier survivorship using any part of the prosthesis removed or revised for any reason as the end point was 95.8% (95% confidence interval, 93.7%-95.5%), and with aseptic loosening as the end point, it was 98.6% (95% confidence interval, 96.5%-99.4%). The midterm survivorship rates were comparable to those of other posterior-stabilized total condylar designs and are not suggestive of excessive risk of early failure. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
    Clinical Orthopaedics and Related Research 03/2008; 466(2):436-42. DOI:10.1007/s11999-007-0070-x · 2.88 Impact Factor
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    ABSTRACT: Compared to the design of a traditional multi-radius (MR) total knee arthroplasty (TKA), the single-radius (SR) implant investigated has a fixed flexion/extension center of rotation. The biomechanical effectiveness of an SR for functional daily activities, i.e., sit-to-stand, is not well understood. The purpose of the study was to compare the biomechanics underlying functional performance of the sit-to-stand (STS) movement between the limbs containing an MR and an SR TKA of bilateral TKA participants. Sagittal plane kinematics and kinetics, and EMG data for selected knee flexor and extensor muscles were analyzed for eight bilateral TKA patients, each with an SR and an MR TKA implant. Compared to the MR limb, the SR limb demonstrated greater peak antero-posterior (AP) ground reaction force, higher AP ground reaction impulse, less vastus lateralis and semitendinosus EMG during the forward-thrust phase of the STS movement. No significant difference of knee extensor moment was found between the two knees. Some GRF and EMG differences were evident between the MR and SR limbs during STS movement. Compensatory adaptations may be used to perform the STS.
    Dynamic Medicine 02/2008; 7:12. DOI:10.1186/1476-5918-7-12
  • Isao Asayama, Tracy L Kinsey, Ormonde M Mahoney
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    ABSTRACT: We evaluated clinical, radiographic, and short-term recovery outcomes in an 18-month 1 surgeon series of 102 unilateral primary total hip arthroplasties performed by direct lateral approach through standard size (15-20 cm) and limited (<10 cm) incisions. Patients were blinded to incision type. Observed measures related to hematological status, transfusions, operative time, hospitalization time, narcotic use, rehabilitation, and discharge disposition did not appear to differ by incision type. Components were well placed in both groups. Intraoperative femoral fractures occurred in 2 limited-incision cases. At 2 years' minimum follow-up, we did not observe evidence that minimally invasive surgical technique provided clinically significant benefit to these patients.
    The Journal of Arthroplasty 01/2007; 21(8):1083-91. DOI:10.1016/j.arth.2005.09.014 · 2.37 Impact Factor
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    ABSTRACT: The purpose of the study was to investigate the influence of the mechanical differences between a single-radius total knee arthroplasty (SR TKA) and a multi-radius (MR) TKA design on the functional performance during a sit-to-stand movement. Three-dimensional kinematics and electromyography for selected knee flexor and extensor muscles were obtained for 16 (8 SR and 8 MR) unilateral, posterior-stabilized TKA participants. Compared to the SR group, the MR group demonstrated compensatory adaptations, with increases in performance time, trunk flexion displacement and velocity, and knee extensor electromyography; and greater relative hamstring co-activation of the MR limbs was needed to increase joint stability. An initial knee abduction displacement was exhibited by more MR than SR participants. In conclusion, SR TKA provides functional benefits to patients.
    The Journal of Arthroplasty 01/2007; 21(8):1193-9. DOI:10.1016/j.arth.2006.02.172 · 2.37 Impact Factor
  • Ormonde M. Mahoney, Tracy L. Kinsey
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    ABSTRACT: This article discusses the clinical significance of restoring hip kinematics and the effect of implant design and surgical technique on proper restoration of the anatomic condition of the hip. Incomplete restoration of femoral offset, body weight lever arm, and hip center height could cause subtle functional deficits in patients that conventional clinical outcome measures would not capture, but that may affect safety. We illustrate this with a case example of a patient who suffered falls while attempting to clear low obstacles after a clinically “successful” hip replacement with a 135-degree neck shaft angle stem that did not restore femoral offset.
    Seminars in Arthroplasty 06/2006; 17(2):32–34. DOI:10.1053/j.sart.2006.05.005
  • Ormonde M Mahoney, Tracy L Kinsey
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    ABSTRACT: Restoration of proper joint line position in revision total knee arthroplasty is essential in promoting recovery of function. We retrospectively analyzed joint line restoration and clinical outcomes in 22 consecutive femur revision cases using modular offsets of variable length and direction between the intramedullary fixation rod and the femoral component. Flexion and extension gap balancing techniques and medial epicondylar referencing was used to achieve proper position of the joint line. Position of the reconstructed joint line from postoperative radiographs was compared to the baseline position of intended anatomic placement determined from pre-operative planning radiographs. Postoperative joint line height averaged 1.6 mm distal to baseline (range, 5 mm distal to 2.5 proximal). Joint line was restored to within 2 mm of anatomic position in 12 of the 22 knees. Sixteen patients received conventional, minimally constrained tibial inserts, and joint stability was achieved in all cases. Level of Evidence: Therapeutic study, Level IV (case series). See Guidelines for Authors for a complete description of levels of evidence.
    Clinical Orthopaedics and Related Research 06/2006; 446(446):93-8. DOI:10.1097/01.blo.0000214425.44582.6b · 2.88 Impact Factor
  • Medicine &amp Science in Sports &amp Exercise 05/2006; 38(5). DOI:10.1249/00005768-200605001-00196 · 4.46 Impact Factor
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    ABSTRACT: We evaluated 60 limbs in 30 patients with unilateral primary total hip arthroplasty and nondiseased contralateral hip. The ratio of femoral offset (FO) to the body weight lever arm (FO ratio) and the ratio of the height of hip center (HC) to pelvic height (HC ratio) were calculated on radiographs. Isometric hip abductor strength was measured by dynamometer. The ratio of normalized strength of the reconstructed side to that of the nonoperated side was calculated (strength ratio). The FO ratio correlated positively to the strength ratio (r = 0.491; P = .0059), whereas the HC ratio correlated negatively (r = -0.568; P = .0011). Slight increase of FO ratio along with restoration of normal hip joint center erring on the side of slight inferomedial cup positioning appeared to optimize hip abductor function.
    The Journal of Arthroplasty 07/2005; 20(4):414-20. DOI:10.1016/j.arth.2004.01.016 · 2.37 Impact Factor

Publication Stats

261 Citations
61.00 Total Impact Points


  • 2012–2013
    • University of North Carolina at Chapel Hill
      North Carolina, United States
  • 2007
    • University of Georgia
      Атина, Georgia, United States
  • 2006
    • Waco Orthopedic and Sports Medicine Clinic
      Waco, Texas, United States
  • 2005
    • Chiang Mai University
      • Department of Physical Therapy
      Amphoe Muang Chiang Mai, Chiang Mai, Thailand