Patient-Specific Instrumentation in Total Knee Arthroplasty Provides No Improvement in Component Alignment

Background: The goal of obtaining more accurate component alignment in total knee arthroplasty (TKA) has led to the development of techniques like portable accelerometer-based handheld navigation system, computer assisted system, patient specific instrumentation. Among which hand held navigation has showed promising results for achieving accurate resection and alignment and only few studies were done to assess radiological outcome or the effective component alignment using portable accelerometer-based hand held navigation system in TKA.Methods: TKA using portable accelerometer-based hand held navigation system (Smith and Nephew- knee align) was done on 25 knees with primary osteoarthritis. Preoperative and post-operative mechanical axis and component alignments were measured using hip-to-ankle radiographs.Results: Among the femoral components, 92.0% were placed within 90°±2° to the femoral mechanical axis in the coronal and 96.0% of the tibial components were placed within 90°±2° to the mechanical axis in the coronal plane, 94.3% of the TKAs had an overall lower extremity alignment within 3° of neutral to the mechanical axis, based on postoperative hip-to-ankle radiographs.Conclusions: The degree of accuracy in positioning the femoral and tibial component in TKA using portable accelerometer-based hand held navigation system (knee align) is very much promising and is an effective intraoperative tool for reducing the proportion of outliers for component placement and thus decreasing the chances of instability and early wear and tear of the components in TKA.

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Should we abandon the patient-specific instrumentation ship in total knee arthroplasty? Not quite yet!

BMC Musculoskeletal Disorders ◽

10.1186/s12891-021-04581-2 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

László Török ◽

Péter Jávor ◽

Petra Hartmann ◽

László Bánki ◽

Endre Varga

Keyword(s):

Total Knee Arthroplasty ◽

Postoperative Complications ◽

Knee Arthroplasty ◽

Meta Analysis ◽

Patient Specific ◽

Transfusion Rate ◽

Component Alignment ◽

Patient Specific Instrumentation ◽

Patient Reported ◽

Total Knee

AbstractPatient-specific Instrumentation (PSI) is an innovative technique aiding the precise implementation of the preoperative plan during total knee arthroplasty (TKA) by using patient-specific guides and cutting blocks. Despite of the theoretical advantages, studies have reported contradictory results, thus there is no consensus regarding the overall effectiveness of PSI. Through the critical assessment of a meta-analysis published lately, this correspondence aims to highlight the complexity of comparing the efficacy of PSI to standard instrumentation (SI). The accuracy of component alignment, patient-reported outcome measures (PROMs), surgery time, blood loss, transfusion rate, and postoperative complications are commonly used outcomes for investigating the efficacy of PSI-aided TKA. By assessing component alignment, the expertise of the surgeon(s) should be taken into consideration, since PSI may not provide benefits for expert surgeons but might improve accuracy and patient safety during the learning curve of novice surgeons. With respect to PROMs and postoperative complications, PSI may not improve short-term results; however, long-term follow up data is missing. Regarding transfusion rates, favorable trends can be observed, but further studies utilizing recent data are needed for a clear conclusion. When assessing surgery time, we suggest focusing on operating room turnover instead of procedure time.

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