Chin Med J 2014;127 (6)1062

DOI: 10.3760/cma.j.issn.0366-6999.20132488Department of Orthopaedics, Beijing Jishuitan Hospital, Beijing 100035, China (Zhou XH, Zhang L and Zhou YX)Department of Orthopeadic, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China (Wang M and Liu C)Correspondence to: Dr. Wang Min, Department of Orthopeadic, Xinqiao Hospital, Third Military Medical University, No. 2 Xinqiao Street, Chongqing 400037, China (Tel: 86-23-68774308. Email: 52solar@sina.cn)

Original articleTotal knee arthroplasty for severe valgus knee deformityZhou Xinhua, Wang Min, Liu Chao, Zhang Liang and Zhou Yixin

Keywords: total knee arthroplasty; variant-III valgus knees

Background Primary total knee arthroplasty (TKA) in severe valgus knees may prove challenging, and choice of implant depends on the severity of the valgus deformity and the extent of soft-tissue release. The purpose of this study was to review 8 to 11 years (mean, 10 years) follow-up results of primary TKA for varient-III valgus knee deformity with use of different type implants. Methods Between January 2002 and January 2005, 20 women and 12 men, aged 47 to 63 (mean, 57.19±6.08) years old, with varient-III valgus knees underwent primary TKA. Of the 32 patients, 37 knees had varient-III deformities. Pie crusting was carefully performed with small, multiple inside-out incisions, bone resection balanced the knee in lieu of soft tissue releases that were not used in the series. Cruciate-retaining knees (Gemini MKII, Link Company, Germany) were used in 13 knees, Genesis II (Simth & Nephew Company, USA) in 14 knees, and hinged knee (Endo-Model Company, Germany) in 10 knees. In five patients with bilateral variant-III TKAs, three patients underwent 1-stage bilateral procedures, and two underwent 2-stage procedures. All implants were cemented and the patella was not resurfaced. The Hospital for Special Surgery (HSS) knee score was assessed. Patients were followed up from 8 to 11 years.Results The mean HSS knee score were improved from 50.33±11.60 to 90.06±3.07 (P <0.001). The mean tibiofemoral alignment were improved from valgus 32.72º±9.68º pre-operation to 4.89º±0.90º post-operation (P <0.001). The mean range of motion were improved from 93.72º±23.69º pre-operation to 116.61±16.29º post-operation (P <0.001). No patients underwent revision. One patient underwent open reduction and internal fixation using femoral condylar plates for supracondylar femoral fractures secondary to a fall at three years. Three patients developed transient peroneal nerve palsies, which resolved within nine months. Two patients developed symptomatic deep vein thrombosis that was managed with rivaroxaban and thrombo-embolic deterrent stockings. There was no incidence of pulmonary embolism. Postoperative patient satisfaction was 80.7±10.4 points in the groups. Prosthetic survival rate was 100% at mean 10 years post-operative.Conclusions Not only hinged implants can be successfully used in variant-III valgus knees. As our results show, if proper ligament balancing techniques are used and proper ligament balance is attained, the knee may not require the use of a more constrained components. Our results also present alternative implant choices for severe knee deformities.

Chin Med J 2014;127 (6): 1062-1066

Severe valgus knees are defined as those with a valgus alignment of >20° on standing anteroposterior

radiographs1,2 and classified as variant-III,3 which account for 5% of all valgus deformities. Variant-III deformities are distinguished by attenuation of the medial capsular ligament complex, marked lateral soft-tissue contracture, and marked osseous deficiency of both the lateral femoral condyle and the lateral tibial plateau. Soft-tissue balance is difficult to achieve and a constrained type of implant is often required. The purpose of this report was to review the long-term results of knee arthroplasty achieved in knees with a preoperative severe valgus orientation.

METHODS

Between January 2002 and January 2005, 20 women and 12 men, aged 47 to 63 years old (mean, 57.19±6.08), with severe valgus knees, underwent primary total knee arthroplasty (TKA) by a senior surgeon for rheumatoid arthritis (n=10) or primary osteoarthritis (n=22). Demographic data on the patients are summarized as height (160.13±9.54) cm, weight (65.06±12.65) kg, and body mass index (BMI) (25.15±2.93) kg/m2. With regard

to these patients, 37 knees had severe valgus deformities defined as type-III.4 The preoperative weight bearing valgus (tibiofemoral alignment) was between 21° and 52° (mean, 32.72°±9.68°) (Figures 1A, 2A and 3A). There was no history of proximal tibial or distal femoral osteotomy. Any patient who had neurological disorders, diabetes mellitus, severe osteoarthritis of the hip joints or muscular imbalance in the lower extremities was excluded from the study. Each patient was subjected to spinal epidural anesthesia. The knee was exposed in flexion using a midline longitudinal skin incision and a lateral parapatellar arthrotomy that permited direct exposure of the contracted soft tissue in the lateral aspect of the kneel. In this orientation an extensive lateral release is much easier to perform. A tourniquet was

Chinese Medical Journal 2014;127 (6) 1063

used. In five patients with bilateral variant-III TKAs, three patients underwent 1-stage bilateral procedures, and two underwent 2-stage bilateral procedures.

The tibia was then prepared using an extra-medullary jig at first, the femur was prepared using intramedullary instruments. The distal femur was resected in 6º of valgus. The rotational alignment of the femur was referenced to the Whiteside line and transepicondylar axis. In some cases of valgus deformity, the lateral epicondyle is not prominent, and defining a distinct lateral point for the axis may be imprecise. With these axises in view, the amount of posterior femoral condylar deformity is estimated. A spacer block was then used to check the flexion and extension gaps. The selective release of the tight lateral structures technique (Pie crusting) was carefully performed with small, multiple inside-out incisions. The release always started from the posterolateral capsule at the level of the tibial cut and then moved anteriorly to involve the lateral

Figure 3. A 78-year-old male patient suffering right severe knee deformity. A: AP radiograph of right knee. B, C: AP and lateral radiograph of right knee postoperation.

Figure 1. A 67-year-old female patient suffering from OA with left severe valgus deformity. A: Left knee clinical photograph preoperation. B: Clinical photograph postoperation. C, D: Radiograph of left knee pre-operation. E, F: Radiograph after TKA with a CR prosthesis (Link company, Germany).

Figure 2. A 64-year-old female patient with severe left knee valgus deformity. A: Left knee clinical photograph pre-operation. B: Pre-operative full leg standing X-ray shows valgus knee deformity. C, D: Radiograph after TKA with use of hinge knee prosthesis (Link company, Germany). E: Left knee clinical photograph post-operation. F: Radiograph of left knee shows dislocation of patellar.

Chin Med J 2014;127 (6)1064

collateral ligament and the iliotibial band. The popliteus tendon was released in nine knees, and gap changes were tested by spacer block after each puncture until gap symmetry was achieved. All 37 severe knees obtained symmetrical flexion and extension gaps under fractional lengthening by means of gradual release of the lateral collateral ligament (LCL). Based on the competency of the medial collateral ligament, advancement of the ligament was not needed in any of the knees. Lateral release must be performed in a graduated, organized stepwise fashion to provide adequate stability without over releasing. Finally, we assessed gap balancing by placing the trial components and applying varus and valgus stress to the knee again until gap symmetry was seen. Patellar maltracking was judged by a no-thumb technique.

Valgus was predominantly of femoral origin, bone deficits in the lateral femoral condyle (15 knees) or lateral the tibial plateau (three knees) may require bone-grafting as estimated, and the remaining defects in six lateral femoral condyles were filled with autograft bone taken from other cuts during the procedure. Bone resection balance of the knee in lieu of soft tissue releases were not used in the series, and a tibial tubercle osteotomy is not suggested here yet.

In the 37 knees with a variant-III deformity, cruciate-retaining knees (Gemini MK II, Link Company, Germany. Figure 1E and 1F) were used in 13 knees, Posterior Sacrified implant Genesis II (Simth & Nephew Company, USA, Figure 3B and 3C) in 14 knees, and hinged knee (Endo-Model Company, Germany. Figure 2C and 2D) in 10 knees. All implants were cemented and the patella was not resurfaced. Postoperatively the knees were placed in 10º of flexion for 3–4 days to prevent stretching of the peroneal nerve, active and passive range-of-motion exercises (within a range of 10º to 70º) were allowed. The mean duration of hospital stay was 14 days with a range of 12–15 days. Patients were followed up by the same surgeon at 3, 6, and 12 months, and then yearly.

The Hospital for Special Surgery (HSS) knee score was assessed. Limb alignment, patellar position, and evidence of loosening or osteolysis were assessed using standing anteroposterior, lateral, and skyline radiographs according to the Knee Society roentgenographic evaluation system. Mediolateral stability was assessed by a varus-valgus stress in full extension. Anteroposterior stability was assessed by an anteroposterior stress test in 30º and 90º of flexion. The patient’s active range of motion was measured using a goniometer. Patient satisfaction was assessed by the questioner as 100 points at full mark, with the best condition equaling 100 points.

Statistical analysis was performed using SPSS 13.0 (SPSS, Inc., Chicago, IL), the paired t-test or independent-samples t-test was employed for comparison of preoperative and postoperative results. Results were considered statistically significant at P <0.05.

RESULTS

Routine postoperative care after all total knee arthroplasties included early mobilization, walking with full weight-bearing, and quadriceps-strengthening and range-of-motion exercises beginning after 2–3 days postoperatively under a physiotherapist’s supervision.

All patients were followed up for 8 to 11 years (mean of 10 years), all knees had good patellar position and were clinically stable in both mediolateral and anteroposterior planes. The mean HSS knee score was improved from 50.33±11.60 (range, 30º–70º) preoperation to 90.06±3.07 (range, 83º–95º) postoperation. There was significant improvement in the postoperative knee score (P <0.001). The mean tibiofemoral alignment was improved from valgus 32.72º±9.68º (range, 21º–52º) preoperation to 4.89º±0.90º (range, 3º–9º) postoperation (Figures 1B, 1E, 1F, 2C-2E, 3B and 3C). There were significant differences between the tibiofemoral alignments at preoperation and those at postoperation (P <0.001). The mean range of motion improved from 93.72º±23.69º (range, 47º–127º) preoperation to 116.61º±16.36º (range, 81º–136º) postoperation. There were significant differences between the preoperation and postoperation range of motion in terms of arc of range of motion (P <0.001, Table 1). No patient underwent revision. One patient underwent open reduction and internal fixation using femoral condylar plates for supracondylar femoral fractures secondary to a fall at three years. Three patients developed transient peroneal nerve palsies, which resolved within nine months. Two patients developed symptomatic deep vein thrombosis; there was no incidence of pulmonary embolism.

Four patients had moderate knee pain (4–5 by VAS evaluation), three of them complained of posterior knee pain at passive maximum flexion and one had severe pain for the first seven months after surgery. Only one patient walked with a cane; a bilateral TKRs case. The other patients could walk without canes and could go up or down stairs slowly. Twenty-four patients could participate in recreational sports such as fishing and gardening.

On the skyline radiographs a normal patellar position was observed in 36 knees and abnormal patellar tilt greater than 4° was observed in only one knee. Radiographic evaluation showed no femoral and tibial osteolysis adjacent to components in any patients at the time of the latest follow-up. No tibial or femoral component had radiographic evidence of loosening, and no subsidence was detected. No late-onset instability was displayed in the follow-up. Postoperative patient satisfaction was 80.7±10.4 points in the groups. Prosthetic survival rate was 100% at a mean of

Table 1. Range of motion (degree)Time Extension Flexion ArcPreoperation –0.78±2.49 92.94±23.43 93.72±23.69Postoperation –0.33±1.49 116.28±16.29* 116.61±16.36*

*A significant difference was observed between the preoperation and postoperation in terms of flexion and arc of range of motion (P <0.001).

Chinese Medical Journal 2014;127 (6) 1065

10 years postoperatively

DISCUSSION

To our knowledge, the mean preoperative tibiofemoral valgus angle (32.72°±9.68°) in this study is the highest reported in the literature. All total knee prosthesis achieved satisfactory clinical results in variant-III valgus knees arthroplasty in our study and no revisions were needed for any reason during a mean follow-up of 10 years.

Adequate soft-tissue balance in variant-III valgus knees during TKA is really challenging. Any tight lateral structures were released by means of pie crusting with a low complication rate with this practice. Some authors advocate reconstruction of the medial collateral ligament complex. In this study we did not have medial advancement of the medial collateral ligament as a means to limit the degree of soft-tissue release. This avoided drawbacks such as non-union at the medial collateral ligament advancement site, increased surgery time, and delayed mobilization,5 it also avoided late-onset instability in 100% of these variant-III valgus knees. In our study implants in variant-III knees would not have led to late-onset instability after nearly 10 years. Good stability and deformity correction were reported in all knees, and there was no incidence of flexion instability, mediolateral instability, and there was no patellar dislocation. A tibial tubercle osteotomy is suggested in cases where the Q angle was >20º, but it has inherent risks of non-union and subsequent extensor mechanism problems, it was not used in our cases. Augmentation of the deficient condyle has been suggested by some authors. In our study, augmentation was applied in 18 cases, although Koskinen et al6 reported that augmentation of the deficient condyle with bone graft or metal blocks was not necessary. In the last 25 years, a number of different surgical techniques and implants have been proposed in TKRs, but the variant-III valgus knee still presents a formidable reconstructive challenge. It is unknown whether and how implant variables influence outcomes in the variant-III knee deformities, and there is also no consensus on the degree of implant constraint that should be used in these cases. Our results present an alternative implant choice for the variant-III valgus knee deformities in younger patients.

Choosing the constraint level according to balancing difficulties appears to be more prudent. Girard et al7 published results that each increase of 1º in laxity in valgus augmented the risk of inserting a constrained prosthesis by 1.9 folds (P=0.000 3). Adolph et al3 recommended that more severe deformity may require more aggressive releases and a posterior stabilized constrained, or hinged total knee arthroplasty; hinged implants are recommended in elderly patients with severe irreducible valgus.8 But authors have raised concerns that these high-constraint prosthesis and hinge prostheses represent a higher risk of loosening and exposure to technical difficulties in case of revision.9 Girard et al7 emphasized that high-constraint prostheses have preferentially been used in elderly and less

active patients, as their survival at five years is less than 70%, despite the introduction of newly-conceived, modern implants. Insall and Easley10 suggested that a posterior cruciate ligament-substituting prosthesis should be selected for elderly patients, and many authors have advocated the use of PCL-substituting implant designs, avoiding concerns with PCL balancing and dealing with a potentially abnormal native ligament.11 Conversely, others have published results that supported the use of PCL-retaining designs with various soft tissue balancing techniques.12,13 McAuley et al4 concluded cruciate-retaining implants could be used in a wide range of patients with valgus osteoarthritis. Posterior cruciate-retaining prostheses have significantly improved the survival rate in comparison with posterior cruciate-stabilizing prostheses at fifteen years.14

As our results show, if proper ligament balancing techniques are used and proper ligament balance is attained, the knee may not require the use of a more constrained component. Aglietti et al15 confirms that selective multiple-puncture release of the lateral soft tissues of the knee joint corrects moderate to severe valgus deformities independently from the implant. We have preferred to use the cruciate-retaining model in valgus patients in order to save bone stock for future possible needs, especially among younger patients. We have achieved excellent results in varus or valgus deformity TKAs with the implants. The choice of whether to use a PCL-retaining design or posterior-stabilized design for variant-III TKA is based on limited data, and few trials have been published presenting results of this prosthesis in variant-III valgus knees.

In a study using a cruciate-retaining implant, no significant difference was reported in terms of knee score, alignment, or rate of surgical revision in patients with severe (≥20º) varus or valgus deformity and matched controls.16 Revisions were due to surgical errors and might have been avoided using proper surgical technique rather than implants. Cruciate-retaining implants can be successfully used in valgus knees and implant survival can be improved if at least one of the lateral-stabilizing structures is preserved.4,9 Aglietti et al15 reported a series of patients where a rotating and anteroposterior gliding mobile bearing, cruciate-retaining knee was implanted, and no hinged knees implants were used, although 13% of the patient’s preoperative weight bearing valgus mechanical axis was greater than 20°.

There are some limitations regarding the findings of our current clinical study due to the absence of a large series and long term follow-up, and more extensive functional analyses have to be employed to finally evaluate the theoretical advantage of implants. A constrained implant is also an important alternative selection for a successful TKA for variant-III valgus knees, especial for elderly patients over 75 years. If proper soft-tissue balance cannot be achieved or there is no functional medial collateral ligament present in elderly patients, more constrained implants should be used. The results present an alternative

Chin Med J 2014;127 (6)1066

implant choice for the variant-III valgus knee deformities for patients less than 65 years old.

REFERENCES

1. Beverland D. Management of the severe varus and valgus knee using the low contact stress rotating platform. Orthopedics 2006; 29 (Suppl): S60-S63.

2. Ranawat AS, Ranawat CS, Elkus M, Rasquinha VJ, Rossi R, Babhulkar S. Total knee arthroplasty for severe valgus deformity. J Bone Joint Surg 2005; 87: 271-283.

3. Adolph V, Lombardi Jr, Kathleen L. An algorithmic approach to total knee arthroplasty in the valgus knee. J Bone Joint Surg 2004; 86 (Suppl 2): 62-71.

4. McAuley JP, Collier MB, Hamilton WG, Tabaraee E, Engh GA. Posterior cruciate-retaining total knee arthroplasty for valgus osteoarthritis. Clin Orthop Relat Res 2008; 466: 2644-2649.

5. Elkus M, Ranawat CS, Rasquinha VJ, Babhulkar S, Rossi R, Ranawat AS. Total knee arthroplasty for severe valgus deformity. Five to fourteen-year follow-up. J Bone Joint Surg Am 2004; 86: 2671-2676.

6. Koskinen E, Ville R, Pekka P, Harilainen A, Sandelin J, Tallroth K, et al. Results of total knee replacement with a cruciate-retaining model for severe valgus deformity: a study of 48 patients followed for an average of 9 years. Knee 2011; 18: 145-150.

7. Girard J, Amzallag M, Pasquier G, Mullieza A, Brosseta T, Gougeonc F, et al. Total knee arthroplasty in valgus knees: Predictive preoperative parameters influencing a constrained design selection. Orthop Traumatol Surg Res 2009; 95: 260-266.

8. Williot A, Rosset P, Favard L, Brilhault J, Burdin P. Total knee

arthroplasty in valgus knee. Orthop Traumatol Surg Res 2010; 96 (Suppl): S37-S42.

9. Pour AE, Parvizi J, Slenker N, Purtill JJ, Sharkey PF. Rotating hinged total knee replacement: use with caution. J Bone Joint Surg (Am) 2007; 89: 1735-1741.

10. Insall JN, Easley ME. Surgical techniques and instrumentation in total knee arthroplasty. In: Surgery of the Knee, 3rd ed. Insall JN, Scott WN, eds. Churchill Livingstone: New York; 2001: 1717-1738.

11. Anderson JA, Baldini A, MacDonald JH, Pellici PM, Sculco TP. Primary constrained condylar knee arthroplasty without stem extensions for the valgus knee. Clin Orthop Relat Res 2006; 442: 199-203.

12. Politi J, Scott R. Balancing severe valgus deformity in total knee arthroplasty using a lateral cruciform retinacular release. J Arthroplasty 2004; 19: 553-557.

13. Engh GA. The difficult knee: severe varus and valgus. Clin Orthop Relat Res 2003; 416: 58-63.

14. Abdel MP, Morrey ME, Jensen MR, Morrey BF. Increased long-term survival of posterior cruciate-retaining versus posterior cruciate-stabilizing total knee replacements. J Bone Joint Surg Am 2011; 93: 2072-2078.

15. Aglietti P, Lup D, Cuomo P, Baldini A, De Luca L. Total knee arthroplasty using a pie-crusting technique for valgus deformity. Clin Orthop Relat Res 2007; 464: 73-77.

16. Ritter MA, Faris GW, Faris PM, Davis KE. Total knee arthroplasty in patients with angular varus or valgus deformities of > or = 20 degrees. J Arthroplasty 2004; 19: 862-866.

(Received September 25, 2013)Edited by Wang De