scholarly journals What is a balanced knee replacement?

2018 ◽  
Vol 3 (12) ◽  
pp. 614-619 ◽  
Author(s):  
Lucy C. Walker ◽  
Nick D. Clement ◽  
Kanishka M. Ghosh ◽  
David J. Deehan

For multifactorial reasons an estimated 20% of patients remain unsatisfied after total knee arthroplasty (TKA). Appropriate tension of the soft tissue envelope encompassing the knee is important in total knee arthroplasty and soft tissue imbalance contributes to several of the foremost reasons for revision TKA, including instability, stiffness and aseptic loosening. There is debate in the literature surrounding the optimum way to achieve balancing of a total knee arthroplasty and there is also a lack of an accepted definition of what a balanced knee replacement is. It may be intuitive to use the native knee as a model for balancing; however, there are many difficulties with translating this into a successful prosthesis. One of the foundations of TKA, as described by Insall, was that although the native knee has more weight transmitted through the medial compartment this was to be avoided in a TKA as it would lead to uneven wear and early failure. There is a focus on achieving symmetrical tension and pressure and subsequent ‘balance’ in TKA, but the evidence from cadaveric studies is that the native knee is not symmetrically balanced. As we are currently trying to design an implant that is not based on its anatomical counterpart, is it possible to create a truly balanced prosthesis or to even to define what that balance is? The authors have reviewed the current evidence surrounding TKA balancing and its relationship with the native knee. Cite this article: EFORT Open Rev 2018;3:614-619. DOI: 10.1302/2058-5241.3.180008.

2020 ◽  
Vol 102-B (3) ◽  
pp. 276-279 ◽  
Author(s):  
Sam Oussedik ◽  
Matthew P. Abdel ◽  
Jan Victor ◽  
Mark W. Pagnano ◽  
Fares S. Haddad

Dissatisfaction following total knee arthroplasty is a well-documented phenomenon. Although many factors have been implicated, including modifiable and nonmodifiable patient factors, emphasis over the past decade has been on implant alignment and stability as both a cause of, and a solution to, this problem. Several alignment targets have evolved with a proliferation of techniques following the introduction of computer and robotic-assisted surgery. Mechanical alignment targets may achieve mechanically-sound alignment while ignoring the soft tissue envelope; kinematic alignment respects the soft tissue envelope while ignoring the mechanical environment. Functional alignment is proposed as a hybrid technique to allow mechanically-sound, soft tissue-friendly alignment targets to be identified and achieved. Cite this article: Bone Joint J 2020;102-B(3):276–279.


Author(s):  
Justin S. Chang ◽  
Babar Kayani ◽  
Charles Wallace ◽  
Fares S. Haddad

Aims Total knee arthroplasty (TKA) using functional alignment aims to implant the components with minimal compromise of the soft-tissue envelope by restoring the plane and obliquity of the non-arthritic joint. The objective of this study was to determine the effect of TKA with functional alignment on mediolateral soft tissue balance as assessed using intraoperative sensor-guided technology. Methods This prospective study included 30 consecutive patients undergoing robotic-assisted TKA using the Stryker PS Triathlon implant with functional alignment. Intraoperative soft tissue balance was assessed using sensor-guided technology after definitive component implantation; soft tissue balance was defined as intercompartmental pressure difference (ICPD) of < 15 psi. Medial and lateral compartment pressures were recorded at 10°, 45°, and 90° of knee flexion. This study included 18 females (60%) and 12 males (40%) with a mean age of 65.2 years (SD 9.3). Mean preoperative hip-knee-ankle deformity was 6.3° varus (SD 2.7°). Results TKA with functional alignment achieved balanced medial and lateral compartment pressures at 10° (25.0 psi (SD 6.1) vs 23.1 psi (SD 6.7), respectively; p = 0.140), 45° (21.4 psi (SD 5.9) vs 20.6 psi (SD 5.9), respectively; p = 0.510), and 90° (21.2 psi (SD 7.1) vs 21.6 psi (SD 9.0), respectively; p = 0.800) of knee flexion. Mean ICPD was 6.1 psi (SD 4.5; 0 to 14) at 10°, 5.4 psi (SD 3.9; 0 to 12) at 45°, and 4.9 psi (SD 4.45; 0 to 15) at 90° of knee flexion. Mean postoperative limb alignment was 2.2° varus (SD 1.0°). Conclusion TKA using the functional alignment achieves balanced mediolateral soft tissue tension through the arc of knee flexion as assessed using intraoperative pressure-sensor technology. Further clinical trials are required to determine if TKA with functional alignment translates to improvements in patient satisfaction and outcomes compared to conventional alignment techniques.


2017 ◽  
Vol 5 (5_suppl5) ◽  
pp. 2325967117S0015
Author(s):  
Gavin Clark ◽  
Luke Mooney

Objectives: Current techniques in Total Knee Arthroplasty(TKA) are utilitarian in that all patients are recommended to have the same alignment of neutral mechanical axis. It has been well established that the population has a varied natural alignment with less than 20% of patients naturally neutral. The ability to predictably individualise alignment for patients is hypothesised to result in greater patient satisfaction. This technique aims to modify mechanical axis technique to consider an individual’s soft tissue constraints. Methods: Soft Tissue Envelope Preserving (STEP) is an operative technique for performing TKA that utilises the soft tissue data obtained intra-operatively from computer navigation registration to determine the optimal alignment to provide balanced positioning of implants without the need for soft tissue releases. Hence balance is achieved through bone cuts rather than altering the patient’s soft tissue balance. The technique will be described in detail. Results: The last 100 patients performed with complete data sets including navigation files and both pre-op and one year post operative outcome measures were reviewed. The spread of overall alignments and bony resections have been compiled with no outliers outside 5 degrees of neutral. The clinical results were comparable with other series and patient satisfaction of greater than 90% was reported. There were no MCL or LCL releases performed. Ilio-tibial band partial releases were the only reported soft tissue releases made. Conclusions: This technique is a safe and effective method of performing TKA with good short term outcomes. It minimises the use of soft tissue releases by utilising the patient’s own soft tissue envelope to balance the knee whilst maintaining the basic principles of a measured resection mechanical axis technique. It has resulted in excellent patient satisfaction in the short term.


10.29007/wrvx ◽  
2019 ◽  
Author(s):  
Jingwei Zhang ◽  
Manoshi Bhowmik-Stoker ◽  
Laura Scholl ◽  
Caitlin Condrey ◽  
Kevin Marchand ◽  
...  

The purpose of this work was to determine the number of soft tissue releases and component orientation of valgus cases performed with Robotic-Arm Assisted total knee arthroplasty (RATKA).This study was a retrospective chart review of cases performed by a single surgeon from July 2016 to December 2017. 72 RATKA cases were defined as having a valgus deformity pre-operatively. Patient demographics and intraoperative surgical details were collected, including initial and final 3D component alignment, knee balancing gaps, full or partial releases. Post- operatively, radiographs, adverse events, and reduced WOMAC pain and KOOS Jr scores were collected at 6 months post-operatively.Pre-operatively, knee deformities ranged from 1o to 12° with fixed flexion contracture. All knees were corrected within 2.5 degrees of mechanical neutral. Medial and lateral gaps were balanced in extension 100% of cases and flexion 93% of cases.Radiographic evidence suggested well seated and well-fixed components. No revision and re- operation is reported. Patient reported outcomes measures collected at 6-month follow up indicated an improvement in WOMAC pain score from 9.6 to 3.2 and improvement in KOOS Jr from 44.7 to 74.4 points.In this retrospective case review, soft tissue releases were not needed to address valgus knees ranging from 1-12° of deformity. The surgeon was able to balance the knee with bone resections and avoid disturbing the soft tissue envelope. While this study has a number of limitations, RATKA for valgus knees should continue to be investigated in a multicenter study.


2018 ◽  
Vol 33 (7) ◽  
pp. S249-S252 ◽  
Author(s):  
Stephen Yu ◽  
Matthew Siow ◽  
Khalid Odeh ◽  
William J. Long ◽  
Ran Schwarzkopf ◽  
...  

Author(s):  
Meredith Perkins ◽  
Julie Lowell ◽  
Christina Arnholt ◽  
Daniel MacDonald ◽  
Anita L. Kerkhof ◽  
...  

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Jake von Hintze ◽  
Mika Niemeläinen ◽  
Harri Sintonen ◽  
Jyrki Nieminen ◽  
Antti Eskelinen

Abstract Background The purpose of this study was to determine the mid-term clinical, radiographic and health-related quality of life (HRQoL) outcomes and define the survival rate in patients who had undergone revision total knee arthroplasty (TKA) using the single rotating hinged knee (RHK) design. Methods Between January 2004 and December 2013, 125 revision TKAs were performed at our institution using the single RHK implant. We conducted both a retrospective analysis of prospectively collected outcome data of these patients and a prospective follow-up study of all 39 living patients (41 knees). The follow-up phase included an optional extra follow-up visit, PROM questionnaires, and plain radiographs. Results The ten-year Kaplan-Meier survival rate of the revision RHK knees was 81.7% (95% CI 71.9–91.6%) with re-revision for any reason as the endpoint. Overall, 15 knees (12% of the total) underwent re-revision surgery during the follow-up. The median follow-up was 6.2 years (range, 0–12.7 years) post-operatively for the baseline group. One mechanical hinge mechanism-related failure occurred without any history of trauma or infection. At the time of the final follow-up, the majority of patients evinced a fairly good clinical outcome measured with patient-reported outcome measures and none of the components were radiographically loose. Conclusion We found that in patients undergoing complex revision TKA, fairly good functional outcome and quality of life can be achieved using an RHK implant. Further, it seems that in this type of patient cohort, revision TKA using an RHK implant relieves pain more than it improves ability to function. The NexGen® RHK design can be regarded as a suitable option in complex revision TKA.


Author(s):  
Eitan Ingall ◽  
Christian Klemt ◽  
Christopher M. Melnic ◽  
Wayne B. Cohen-Levy ◽  
Venkatsaiakhil Tirumala ◽  
...  

AbstractThis is a retrospective study. Prior studies have characterized the deleterious effects of narcotic use in patients undergoing primary total knee arthroplasty (TKA). While there is an increasing revision arthroplasty burden, data on the effect of narcotic use in the revision surgery setting remain limited. Our aim was to characterize the effect of active narcotic use at the time of revision TKA on patient-reported outcome measures (PROMs). A total of 330 consecutive patients who underwent revision TKA and completed both pre- and postoperative PROMs was identified. Due to differences in baseline characteristics, 99 opioid users were matched to 198 nonusers using the nearest-neighbor propensity score matching. Pre- and postoperative knee disability and osteoarthritis outcome score physical function (KOOS-PS), patient reported outcomes measurement information system short form (PROMIS SF) physical, PROMIS SF mental, and physical SF 10A scores were evaluated. Opioid use was identified by the medication reconciliation on the day of surgery. Propensity score–matched opioid users had significantly lower preoperative PROMs than the nonuser for KOOS-PS (45.2 vs. 53.8, p < 0.01), PROMIS SF physical (37.2 vs. 42.5, p < 0.01), PROMIS SF mental (44.2 vs. 51.3, p < 0.01), and physical SF 10A (34.1 vs. 36.8, p < 0.01). Postoperatively, opioid-users demonstrated significantly lower scores across all PROMs: KOOS-PS (59.2 vs. 67.2, p < 0.001), PROMIS SF physical (43.2 vs. 52.4, p < 0.001), PROMIS SF mental (47.5 vs. 58.9, p < 0.001), and physical SF 10A (40.5 vs. 49.4, p < 0.001). Propensity score–matched opioid-users demonstrated a significantly smaller absolute increase in scores for PROMIS SF Physical (p = 0.03) and Physical SF 10A (p < 0.01), as well as an increased hospital length of stay (p = 0.04). Patients who are actively taking opioids at the time of revision TKA report significantly lower preoperative and postoperative outcome scores. These patients are more likely to have longer hospital stays. The apparent negative effect on patient reported outcomes after revision TKA provides clinically useful data for surgeons in engaging patients in a preoperative counseling regarding narcotic use prior to revision TKA to optimize outcomes.


2021 ◽  
Vol 29 (1) ◽  
pp. 230949902110020
Author(s):  
Seikai Toyooka ◽  
Hironari Masuda ◽  
Nobuhiro Nishihara ◽  
Takashi Kobayashi ◽  
Wataru Miyamoto ◽  
...  

Purpose: To evaluate the integrity of lateral soft tissue in varus osteoarthritis knee by comparing the mechanical axis under varus stress during navigation-assisted total knee arthroplasty before and after compensating for a bone defect with the implant. Methods: Sixty-six knees that underwent total knee arthroplasty were investigated. The mechanical axis of the operated knee was evaluated under manual varus stress immediately after knee exposure and after navigation-assisted implantation. The correlation between each value of the mechanical axis and degree of preoperative varus deformity was compared by regression analysis. Results: The maximum mechanical axis under varus stress immediately after knee exposure increased in proportion to the degree of preoperative varus deformity. Moreover, the maximum mechanical axis under varus stress after implantation increased in proportion to the degree of preoperative varus deformity. Therefore, the severity of varus knee deformity leads to a progressive laxity of the lateral soft tissue. However, regression coefficients after implantation were much smaller than those measured immediately after knee exposure (0.99 vs 0.20). Based on the results of the regression formula, the postoperative laxity of the lateral soft tissue was negligible, provided that an appropriate thickness of the implant was compensated for the bone and cartilage defect in the medial compartment without changing the joint line. Conclusion: The severity of varus knee deformity leads to a progressive laxity of the lateral soft tissue. However, even if the degree of preoperative varus deformity is severe, most cases may not require additional procedures to address the residual lateral laxity.


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