Unconstrained total knee arthroplasty in significant valgus deformity: a modified surgical technique to balance the knee and avoid instability
- 632 Downloads
Correction of valgus deformity in total knee arthroplasty (TKA) is technically challenging and has produced variable results. A modified surgical technique involving adapting the distal femoral cut with minimal soft tissue release is proposed. The authors hypothesise that using this technique would result in satisfactory radiological and functional outcome.
The technique involves balancing the knee in extension by changing the distal femoral resection angle and confining soft tissue release to only the posterolateral capsule if required. Retrospective analysis of 276 consecutive TKAs performed using this technique under the care of a single surgeon in patients with valgus knee deformity ≥10° was undertaken. An unconstrained mobile bearing implant was used in all knees with a medial para-patellar approach, and outcome scores were collected prospectively. Ninety six percent of the knees were cementless.
Mean coronal alignment of the lower limb was corrected from 15.6° (±5.7°) to 3.8° (±2.5°). 97.8 % knees had their coronal alignment restored to ≤7°. Seventy-eight knees (28 %) were balanced by only changing the distal femoral resection angle. One hundred and ninety-eight knees (72 %) had release of the posterolateral capsule. Sixteen knees (5.8 %) also had release of iliotibial band. Lateral patellar release was performed in 39 knees (14 %). 93.1 % had central patello-femoral alignment. At between 5.8 and 10.5 year follow-up, there has been one spinout, managed by closed reduction, and one revision of tibial tray for subsidence. The mean American Knee Society clinical score improved from 19.1 to 86.5 (±12.2).
Adequate correction of valgus knee deformity was successfully achieved using this modified technique with satisfactory medium-term outcome and avoidance of instability.
KeywordsValgus deformity Total knee arthroplasty Rotating platform Modified surgical technique Mobile bearing Cementless
The authors would like to thank the outcome team in Musgrave Park for help in collecting the data used in the paper, Michael Parker for his statistical advice and Professor James Nixon for his help in editing the paper.
- 7.Buechel FF (1990) A sequential three-step lateral release for correcting fixed valgus knee deformities during total knee arthroplasty. Clin Orthop Relat Res 260:170–175Google Scholar
- 11.Clarke HD, Scott WN, Insall JN, Pedersen HB, Math KR, Vigorita VJ, Cushner FD (2001) Anatomy. In: Insall JN, Scott WN (eds) Surgery of the knee. Churchill Livingstone, New York, pp 13–76Google Scholar
- 15.Ewald FC (1989) The knee society total knee arthroplasty roentgenographic evaluation and scoring system. Clin Orthop Relat Res 248:9–12Google Scholar
- 21.Insall JN, Dorr LD, Scott RD, Scott WN (1989) Rationale of the Knee Society clinical rating system. Clin Orthop Relat Res 248:13–14Google Scholar
- 23.Keblish PA (1991) The lateral approach to the valgus knee: surgical technique and analysis of 53 cases with over two-year follow-up evaluation. Clin Orthop Relat Res 271:52–62Google Scholar
- 26.Krackow KA, Jones MM, Teeny SM, Hungerford DS (1991) Primary total knee arthroplasty in patients with fixed valgus deformity. Clin Orthop Relat Res 273:9–18Google Scholar
- 29.Mullaji A, Kanna R, Marawar S, Kohli A, Sharma A (2007) Comparison of limb and component alignment using computer-assisted navigation versus image intensifier-guided conventional total knee arthroplasty: a prospective, randomized, single-surgeon study of 467 knees. J Arthroplasty 22(7):953–959CrossRefPubMedGoogle Scholar
- 32.Peters CL, Jimenez C, Erickson J, Anderson MB, Pelt CE (2013) Lessons learned from selective soft-tissue release for gap balancing in primary total knee arthroplasty: an analysis of 1216 consecutive total knee arthroplasties: AAOS exhibit selection. J Bone Joint Surg Am 95(20):e152CrossRefPubMedPubMedCentralGoogle Scholar
- 34.Ritter MA, Faris PM, Keating EM, Meding JB (1994) Postoperative alignment of total knee replacement. Its effect on survival. Clin Orthop Relat Res 299:153–156Google Scholar
- 35.Scuderi GR, Insall JN (1995) Fixed varus and valgus deformities. In: Lotke PA (ed) Knee Arthroplasty. Raven Press, Ltd., New York, pp 111–127Google Scholar
- 39.Stern SH, Moeckel BH, Insall JN (1991) Total knee arthroplasty in valgus knees. Clin Orthop Relat Res 273:5–8Google Scholar
- 44.Whiteside LA (1993) Correction of ligament and bone defects in total arthroplasty of the severely valgus knee. Clin Orthop Relat Res 234–245(288):234–245Google Scholar
- 46.Windsor RE, Scuderi GR, Moran MC, Insall JN (1989) Mechanisms of failure of the femoral and tibial components in total knee arthroplasty. Clin Orthop Relat Res 248:15–20Google Scholar