Ethan Krell1, Amethia Joseph1, Joseph Nguyen2, Alejandro Gonzalez Della Valle3. 1. Department of Orthopaedic Surgery, Hospital for Special Surgery, Weill Medical College of Cornell University, 535 East 70th Street, New York, NY, 10021, USA. 2. Department of Biostatistics, Hospital for Special Surgery, Weill Medical College of Cornell University, New York, NY, USA. 3. Department of Orthopaedic Surgery, Hospital for Special Surgery, Weill Medical College of Cornell University, 535 East 70th Street, New York, NY, 10021, USA. gonzaleza@hss.edu.
Abstract
BACKGROUND: Adequate soft tissue tension and balance is paramount to achieve favourable outcomes of total knee arthroplasty (TKA). Implant manufacturers offer 1-mm liner increments to fine-tune ligament tension and balance. In this study, we assessed if soft tissue tension changes introduced by minimal changes in liner thicknesses affect early patient reported outcomes. METHODS: Eighty-nine patients undergoing 99 primary, elective TKAs by a single surgeon were included. After achieving adequate ligament balance, the first 50 knees received an insert that would allow 2-3 mm of medial and lateral opening (control group), whereas the last 49 received an insert which was 1 mm thicker, resulting in a slight increase in ligament tension (study group). Sensor technology was used to record compartmental loads. Knee Society Score (KSS), KOOS Jr., and ROM were recorded pre-operatively, six weeks, four and 12 months post-operatively. The Forgotten Joint Score (FJS) was administered four and 12 months post-operatively. RESULTS: No differences were observed in demographic variables, pre-operative outcome scores, and ROM measures between groups. Six weeks post-operatively, there was no statistically significant difference in the outcome variables. Four months post-operatively, statistically significant differences were only observed in KOOS Jr. (79 and 73.6; p = 0.05), and FJS (59.9 and 45.5; p < 0.01); all of which favoured the control group. There was no difference in the outcome variables at 12 months. CONCLUSION: Minor changes in soft tissue tension induced by 1-mm changes in liner thickness resulted in clinically meaningful differences favouring the control group four months post-operatively, but in no clinically noticeable differences 12 months post-operatively. It is possible that lower soft tissue tension may lead to transient improvement in patient-reported early outcomes.
BACKGROUND: Adequate soft tissue tension and balance is paramount to achieve favourable outcomes of total knee arthroplasty (TKA). Implant manufacturers offer 1-mm liner increments to fine-tune ligament tension and balance. In this study, we assessed if soft tissue tension changes introduced by minimal changes in liner thicknesses affect early patient reported outcomes. METHODS: Eighty-nine patients undergoing 99 primary, elective TKAs by a single surgeon were included. After achieving adequate ligament balance, the first 50 knees received an insert that would allow 2-3 mm of medial and lateral opening (control group), whereas the last 49 received an insert which was 1 mm thicker, resulting in a slight increase in ligament tension (study group). Sensor technology was used to record compartmental loads. Knee Society Score (KSS), KOOS Jr., and ROM were recorded pre-operatively, six weeks, four and 12 months post-operatively. The Forgotten Joint Score (FJS) was administered four and 12 months post-operatively. RESULTS: No differences were observed in demographic variables, pre-operative outcome scores, and ROM measures between groups. Six weeks post-operatively, there was no statistically significant difference in the outcome variables. Four months post-operatively, statistically significant differences were only observed in KOOS Jr. (79 and 73.6; p = 0.05), and FJS (59.9 and 45.5; p < 0.01); all of which favoured the control group. There was no difference in the outcome variables at 12 months. CONCLUSION: Minor changes in soft tissue tension induced by 1-mm changes in liner thickness resulted in clinically meaningful differences favouring the control group four months post-operatively, but in no clinically noticeable differences 12 months post-operatively. It is possible that lower soft tissue tension may lead to transient improvement in patient-reported early outcomes.
Entities:
Keywords:
Ligament balance; Outcomes; Soft tissue tension; Total knee arthroplasty
Authors: Giles R Scuderi; Robert B Bourne; Philip C Noble; James B Benjamin; Jess H Lonner; W N Scott Journal: Clin Orthop Relat Res Date: 2012-01 Impact factor: 4.176
Authors: Ronald E Delanois; Jaydev B Mistry; Morad Chughtai; Alison K Klika; Anton Khlopas; Wael K Barsoum; Carlos A Higuera; Anil Bhave; Michael A Mont Journal: Surg Technol Int Date: 2016-09-10